Major interaction on record — check this product against your medications before combining. Check your meds →
Dietary supplement

Sleep Nighttime Powder Ingredients & Drug Interactions

by youtheory

Sleep Nighttime Powder label
See full label image
Powder Category: Other Combinations
Most serious interaction: Major
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Sleep Nighttime Powder against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Major

Sleep Nighttime Powder is a dietary supplement by youtheory with 6 active ingredients. Its ingredients are commonly taken for sleep quality and insomnia, relaxation, cognitive function.Based on those ingredients, 1,580 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Melatonin, L-Theanine, L-5-Hydroxytryptophan. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Sleep Nighttime Powder by youtheory

Ask about any prescription or over-the-counter medication and we check it for interactions with Sleep Nighttime Powder by youtheory — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
Prefer a human? Send your question to our licensed pharmacists — free, answered by email within 24 hours.

HelloPharmacist Scorecard of Sleep Nighttime Powder by youtheory

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 6 of its 6 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

Youtheory Sleep Nighttime Powder contains 6 active ingredients: L-Glycine, L-Tryptophan, Magnesium, L-5-Hydroxytryptophan (5-HTP), L-Theanine, and Melatonin. These ingredients are intended to support nighttime relaxation and sleep.

The inactive ingredients are natural Lemon-Lime flavor, Silicon Dioxide, and Xanthan Gum.

Does it work?

Strong evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Strong

Clinical evidence supports at least one of this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: Sleep support and relaxation.
  • We looked for evidence on: Anxiety, Delayed sleep phase syndrome (DSPS), Depression, Fibromyalgia, Generalized anxiety disorder (GAD), Cognitive function — and 4 related terms.
  • The strongest evidence on file: Melatonin is rated "Likely Effective" for Delayed sleep phase syndrome (DSPS) (Natural Medicines).
  • Also on file: 5-htp is rated "Possibly Effective" for Depression.
  • Also on file: Melatonin is rated "Possibly Effective" for Pre-procedural anxiety, Jet lag, Beta blocker-induced insomnia.

The evidence for these ingredients in supporting sleep comes directly from their individual studied uses. Melatonin is rated Likely Effective for delayed sleep phase syndrome and non-24-hour sleep-wake disorder, and Possibly Effective for pre-procedural anxiety.

L-Glycine and L-5-HTP are both rated Possibly Effective for depression but show Insufficient Reliable Evidence for sleep specifically. L-Tryptophan is rated Possibly Ineffective for depression and Insufficient Reliable Evidence for anxiety.

L-Theanine is Possibly Effective for cognitive function, and Magnesium is Effective for dyspepsia and constipation but not rated for sleep promotion. The data we hold doesn't establish a firm effectiveness claim for this combination as a sleep aid.

The evidence, ingredient by ingredient Glycine L-tryptophan Magnesium 5-htp Theanine Melatonin

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 6 of the 6 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 6 of 6.
  • General safety write-ups exist for 6 of 6.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Most of these ingredients are generally well tolerated short-term, though long-term safety data are limited for glycine and theanine. Common side effects across the ingredients include drowsiness, nausea, headache, and gastrointestinal upset.

L-Tryptophan has a serious historical note: in 1989, a contamination event in a single Japanese manufacturer's product caused over 1,500 cases of eosinophilia-myalgia syndrome (EMS), a rare neurological disorder. Nearly all cases were traced to that one source, but the risk remains noteworthy.

Melatonin may increase seizure risk in rare cases, and there's concern about mood changes including depression and suicidal thoughts. 5-HTP can cause rare serious effects like hallucinations, mania, and aggression, especially at higher doses.

Side effects, ingredient by ingredient Glycine L-tryptophan Magnesium 5-htp Theanine Melatonin

Meds to double-check

Major interaction found
Known Interaction Concern · database check
Major identified

At least one ingredient has a documented Major-severity interaction. Check your medications for a personalized result.

Why this rating?
  • 6 of the 6 matched ingredients can interact with medications — L-tryptophan, 5-htp, Melatonin, Magnesium, Theanine, among others.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; seizure medications; immunosuppressants / transplant drugs; diabetes medications; heart-rhythm medications; Parkinson's medications.
  • For scale: 1,581 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before taking this product, check with your pharmacist if you take: CNS depressants like sleeping pills or opioids (Major risk from L-tryptophan); antidepressants or other serotonergic drugs like SSRIs and SNRIs (Moderate risk from L-tryptophan and 5-HTP); blood thinners including warfarin or antiplatelet drugs (Moderate risk from melatonin); heart medications including nifedipine or antihypertensive drugs (Moderate risk from melatonin and theanine); clozapine for schizophrenia (Moderate risk from glycine); Parkinson's medication levodopa/carbidopa (Moderate risk from magnesium); anticonvulsants for seizures (Moderate risk from melatonin); or diabetes medications (Moderate risk from melatonin). Additionally, magnesium can interfere with quinolone antibiotics, bisphosphonates, skeletal muscle relaxants, and sulfonylureas.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with clinical evidence supporting its stated purpose. Major medication interactions have been identified, and safety information is well characterized.

This product combines multiple sleep-supporting ingredients but also brings significant interaction risk—particularly if you take antidepressants, sedatives, blood thinners, or heart medications. If you take any prescription medication, check it against the tool on this page before starting.

Talk to your pharmacist or doctor about whether this powder is right for you and to review your complete medication list.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 6 of 6 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Jan 25, 2017.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Sleep Nighttime Powder, straight from the product label.

Brand youtheory
Barcode (UPC) 850502007003
Net contents 0.2 Oz(s); 5.73 Gram(s)
Market status On market
Date entered into DSLD Jan 25, 2017
DSLD ID 69102
Product type Other Combinations
Supplement form Powder
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years)
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Sleep Nighttime Powder by youtheory, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
5.73 Gram(s)
Maximum serving Sizes:
5.73 Gram(s)
Servings per container
1
UPC/BARCODE
850502007003
IngredientAmount% DV
L-Glycine3000 mg--
L-Tryptophan1000 mg--
Magnesium200 mg50%
L-5-Hydroxytryptophan100 mg--
L-Theanine200 mg--
Melatonin0.3 mg--

Other ingredients: natural Lemon-Lime flavor, Silicon Dioxide, Xanthan Gum

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
FDA Statement of Identity

Dietary Supplement

Suggested/Recommended/Usage/Directions

Suggested Use: (Adults) Mix one (1) packet with water or juice, 30 minutes before bedtime.

Precautions

This product is manufactured in a facility that processes whey milk protein and fish extracts.

Usage Warnings: Use only at bedtime. Do not use with antidepressant drugs, alcoholic beverages, when driving a vehicle, or while operating machinery.

Check with your doctor before using this product if you are taking medication or have any medical conditions. Do not use if you are pregnant or nursing. Do not use with antidepressant drugs, alcoholic beverages, when driving a vehicle, or while operating machinery.

Do not exceed the recommended daily intake.

Not intended for persons under 18. KEEP OUT OF REACH OF CHILDREN.

Storage

Store in a cool and dry place after opening.

FDA Disclaimer Statement

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

General

FLM.PP.SPA.00700.V0

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Sleep Nighttime Powder by youtheory label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Sleep Nighttime Powder label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Sleep Nighttime Powder by youtheory

These are the 6 active ingredients this product is made of. Select any to open its full monograph.

Serving size5.73 Gram(s) Dosage formPowder Servings per container1 Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

L-Glycine

Interacts with
1 drug
3000 mg per serving

Glycine is a non-essential amino acid your body makes on its own and that also appears in protein-rich foods. It is most studied for improving sleep q...

L-Glycine monograph & interactions

L-Tryptophan

Interacts with
394 drugs
1000 mg per serving

L-tryptophan is an essential amino acid the body uses to make serotonin and melatonin, and people take it to support sleep and mood. The evidence for...

L-Tryptophan monograph & interactions

Magnesium

Interacts with
295 drugs
200 mg per serving Form: Magnesium Citrate

Magnesium is an essential mineral your body needs for muscles, nerves, blood pressure, and many other functions, and supplements are useful for preven...

Magnesium monograph & interactions

L-5-Hydroxytryptophan

Interacts with
398 drugs
100 mg per serving

5-HTP is a compound your body uses to make serotonin, and people take it as a supplement hoping to improve mood, sleep, and headaches. Some early rese...

L-5-Hydroxytryptophan monograph & interactions

L-Theanine

Interacts with
565 drugs
200 mg per serving

Theanine (usually L-theanine) is an amino acid found naturally in tea leaves that many people take to feel calmer and less stressed without strong dro...

L-Theanine monograph & interactions

Melatonin

Interacts with
1,461 drugs
0.3 mg per serving

Melatonin is a hormone your body makes naturally to help control your sleep-wake cycle, and the supplement form is widely used to help with sleep timi...

Melatonin monograph & interactions

Other (inactive) ingredients: Natural Lemon-Lime flavor, Silicon Dioxide, Xanthan Gum. These complete the product’s ingredient list but are not active constituents.

Interaction report

Sleep Nighttime Powder by youtheory Drug Interactions

Want to check YOUR meds against Sleep Nighttime Powder?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
1,580Drugs
254 Major 1,025 Moderate 301 Minor

Ingredients driving the most interactions

Melatonin 1,461
L-Theanine 565
L-5-Hydroxytryptophan 398
L-Tryptophan 394
Magnesium 295

Individual Drug Interactions

The ingredients in Sleep Nighttime Powder interact with 1,580 drugs. Click any drug to see the details.

6 of the 6 ingredients in Sleep Nighttime Powder interact with drugs. Each result below shows which ingredient is responsible. Melatonin L-Theanine L-5-Hydroxytryptophan L-Tryptophan Magnesium L-Glycine

Each ingredient & the kinds of drugs it affects

For each ingredient in Sleep Nighttime Powder with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.

Melatonin18 drug types · 1,461 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, melatonin may have anticoagulant effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
There are isolated case reports of minor bleeding and decreased prothrombin activity in people taking melatonin with warfarin (Coumadin). The mechanism, if any, of this interaction is unknown. Taking melatonin orally seems to decrease coagulation activity within one hour of dosing in healthy men.

Likelihood Possible Evidence B
Anticonvulsants

Theoretically, melatonin may reduce the effects of anticonvulsants. Some clinical research suggests that melatonin may increase the frequency of seizures in certain patients, particularly children with neurological impairment.

Likelihood Possible Evidence B
Antidiabetes Drugs

Theoretically, taking melatonin with antidiabetes drugs might increase the risk of hypoglycemia.
Some clinical research shows that melatonin reduces levels of fasting blood glucose and improves glycemic control. However, other research suggests that melatonin might impair glucose utilization and increase insulin resistance, while other research has found no effect on glucose levels. Until more is known, use melatonin cautiously in combination with antidiabetes drugs.

Likelihood Possible Evidence B
Antihypertensive Drugs

Theoretically, taking melatonin with antihypertensive drugs might increase the risk of hypotension or hypertension.
Some clinical research suggests that taking melatonin decreases blood pressure in healthy adults. Also, melatonin seems to lower systolic and diastolic blood pressure in individuals with high blood pressure at nighttime or untreated essential hypertension. However, melatonin seems to worsen blood pressure in patients who are taking antihypertensive medications. Immediate-release melatonin 5 mg at night in combination with nifedipine GITS (Procardia XL) increases systolic blood pressure an average of 6.5 mmHg, diastolic blood pressure by an average of 4.9 mmHg, and heart rate by 3.9 bpm. Also, results from animal research suggest that melatonin reduces the effectiveness of certain antihypertensive drugs, including methoxamine and clonidine.

Likelihood Possible Evidence A
Caffeine

Theoretically, taking caffeine with melatonin might increase levels of melatonin.
Some evidence suggests that caffeine consumption can decrease endogenous melatonin levels, while other evidence suggests that caffeine increases endogenous melatonin levels. When administered in combination with melatonin supplements, caffeine seems to increase melatonin effects and levels. The reason for this discrepancy is not completely clear. Part of the discrepancy may result from the fact that caffeine can inhibit melatonin synthesis as well as inhibit melatonin metabolism. By functioning as an adenosine receptor antagonist, caffeine may indirectly inhibit the synthesis of melatonin. Conversely, because melatonin and caffeine are both metabolized by cytochrome P450 1A2 (CYP1A2) enzyme, concomitant use of melatonin and caffeine may reduce the metabolism of melatonin, resulting in higher serum levels.

Likelihood Probable Evidence B
Cns Depressants

Theoretically, taking melatonin might increase the sedative effects of CNS depressants.
Melatonin has sedative effects. Theoretically, concomitant use of melatonin with alcohol, benzodiazepines, or other sedative drugs might cause additive sedation.

Likelihood Possible Evidence D
Contraceptive Drugs

Theoretically, taking contraceptive drugs with melatonin might increase the effects and adverse effects of melatonin.
Contraceptive drugs can increase the levels of endogenous melatonin. Theoretically, these drugs may increase the effects and adverse effects of oral melatonin.

Likelihood Probable Evidence B
Cytochrome P450 1A2 (Cyp1A2) Substrates

Theoretically, melatonin might increase levels of drugs metabolized by CYP1A2. Also, other CYP1A2 substrates might decrease the metabolism of melatonin, increasing melatonin levels.
Melatonin is metabolized in the liver primarily by the CYP2C19 and CYP1A2 enzymes. Theoretically, combined administration of melatonin with drugs metabolized by the CYP1A2 enzyme might reduce the metabolism of these drugs, resulting in increased serum levels. Conversely, some drugs metabolized by CYP1A2 may inhibit the metabolism of melatonin, resulting in increased serum levels of melatonin. Until more is known, use melatonin cautiously in patients taking drugs metabolized by these enzymes.

Likelihood Probable Evidence D
Cytochrome P450 2C19 (Cyp2C19) Substrates

Theoretically, melatonin might increase levels of drugs metabolized by CYP2C19. Also, other CYP2C19 substrates might decrease the metabolism of melatonin, increasing melatonin levels.
Melatonin is metabolized in the liver primarily by the CYP2C19 and CYP1A2 enzymes. Theoretically, combined administration of melatonin with certain drugs metabolized by the CYP2C19 enzyme may reduce the metabolism of these drugs, resulting in increased serum levels. Conversely, some drugs metabolized by CYP2C19 may inhibit the metabolism of melatonin, resulting in increased serum levels of melatonin. Until more is known, use melatonin cautiously in patients taking drugs metabolized by these enzymes.

Likelihood Probable Evidence D
Fluvoxamine (Luvox)

Theoretically, taking fluvoxamine with melatonin might increase levels of melatonin.
Fluvoxamine can significantly increase melatonin levels. In some cases, fluvoxamine might increase bioavailability of exogenously administered melatonin by up to 20 times. Some researchers think this might be a beneficial interaction and be potentially useful for cases of refractory insomnia. However, this interaction might also cause unwanted excessive drowsiness and possibly other adverse effects. Fluvoxamine is known to increase endogenous melatonin secretion. It seems to increase serum levels of exogenously administered melatonin possibly by decreasing melatonin metabolism by inhibiting cytochrome P450 (CYP450) 1A2 and 2C19 or by inhibiting melatonin elimination. This effect has been found in healthy people taking fluvoxamine 50-75 mg and melatonin 5 mg.

Likelihood Probable Evidence B
Immunosuppressants

Theoretically, melatonin might interfere with immunosuppressive therapy.
Melatonin can stimulate immune function. Theoretically, melatonin might interfere with immunosuppressive therapy.

Likelihood Possible Evidence B
Methamphetamine (Desoxyn)

Theoretically, taking melatonin with methamphetamine may increase the adverse effects of methamphetamine.
Animal research suggests that melatonin exacerbates the adverse effects of methamphetamine, resulting in greater depression of tryptophan hydroxylase (TPH) and tyrosine hydroxylase (TH) activity, as well as a significant reduction in dopamine levels. This has not been shown in humans.

Likelihood Possible Evidence D
Nifedipine Gits (Procardia Xl)

Theoretically, taking melatonin with extended release nifedipine reduces the effects of nifedipine.
Melatonin can decrease the effectiveness of extended release nifedipine (GITS). Immediate-release melatonin 5 mg at night in combination with nifedipine GITS 30-60 mg daily increases systolic and blood pressure by an average of 6.5 mmHg and 4.9 mmHg, respectively. Concomitant use with melatonin also increases heart rate by 3.9 bpm. The mechanism of this interaction is not known.

Likelihood Probable Evidence B
Seizure Threshold Lowering Drugs

Theoretically, taking melatonin with drugs that lower the seizure threshold might increase the risk of seizure activity.
Some clinical evidence suggests that melatonin may increase the frequency of seizures in certain patients, particularly children with neurological disabilities.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Theoretically, melatonin may have antiplatelet effects and may increase the risk of bleeding with warfarin.
Three cases of increased prothrombin time have been reported for patients aged 48-72 years who took melatonin orally in combination with warfarin. However, three cases of decreased prothrombin time have also been reported for patients aged 51-84 years who took melatonin orally in combination with warfarin. Until more is known, use melatonin cautiously in patients taking warfarin.

Likelihood Possible Evidence D
Cytochrome P450 2D6 (Cyp2D6) Substrates

Theoretically, melatonin might increase levels of drugs metabolized by CYP2D6.
Laboratory research suggests that certain lots of melatonin inhibit CYP2D6. Theoretically, combined administration of melatonin with certain drugs metabolized by the CYP2D6 enzyme may reduce the metabolism of these drugs, resulting in increased serum levels. Until more is known, use melatonin cautiously in patients taking drugs metabolized by these enzymes.

Likelihood Possible Evidence D
Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, melatonin might increase levels of drugs metabolized by CYP3A4.
Laboratory research shows that certain lots of melatonin inhibit CYP3A4. Theoretically, combined administration of melatonin with certain drugs metabolized by CYP3A4 may reduce the metabolism of these drugs, resulting in increased serum levels. Until more is known, use melatonin cautiously in patients taking drugs metabolized by these enzymes.

Likelihood Possible Evidence D
Flumazenil (Romazicon)

Theoretically, taking flumazenil with melatonin might reduce the effects of melatonin.
Animal research shows that flumazenil may inhibit the effect of melatonin.

Likelihood Possible Evidence D
Melatonin full monograph & interactions

L-Theanine3 drug types · 565 drugs

Antihypertensive Drugs

Theanine might lower blood pressure, potentiating the effects of antihypertensive drugs.
Animal research shows that theanine can lower blood pressure in spontaneously hypertensive animals. Theoretically, concomitant use of theanine and antihypertensive drugs might potentiate the antihypertensive activity.

Likelihood Possible Evidence D
Cns Depressants

Theoretically, theanine might have additive sedative effects when used in conjunction with CNS depressants. However, it is unclear if this concern is clinically relevant.
Theoretically, theanine may compete with glutamate and/or increase plasma gamma-aminobutyric acid (GABA) levels, which could cause CNS depression. In one clinical study, some subjects taking oral theanine reported drowsiness.

Likelihood Unlikely Evidence D
Serotonergic Drugs

Clinical studies regarding the effects of L-theanine on serotonin levels are conflicting. Some studies suggest it can increase serotonin levels in the brain while others report that it may decrease them. Nevertheless, there have been no reports of l-theanine being a causative agent in serotonergic-related side effects or serotonin syndrome.

Likelihood Unlikely Evidence C
L-Theanine full monograph & interactions

L-5-Hydroxytryptophan3 drug types · 398 drugs

Carbidopa (Lodosyn)

Combining 5-HTP and carbidopa can increase the risk of serotonergic side effects.
Carbidopa is sometimes used with 5-HTP to minimize peripheral 5-HTP metabolism and boost the amount that reaches the brain. However, this combination might also increase the risk of some side effects including hypomania, restlessness, rapid speech, anxiety, insomnia, and aggressiveness. Combining carbidopa and 5-HTP might also increase the risk of scleroderma-like skin changes due to elevated serotonin levels.

Likelihood Possible Evidence D
Cns Depressants

Theoretically, concomitant use of 5-HTP with medications that cause sedation might have additive effects.
In clinical trials, 5-HTP has been associated with drowsiness and somnolence.

Likelihood Possible Evidence D
Serotonergic Drugs

Combining serotonergic drugs with 5-HTP might cause additive serotonergic effects.
5-HTP can increase serotonin levels and cause serotonergic effects. Theoretically, combining serotonergic drugs with 5-HTP might increase the risk of serotonergic side effects, including serotonin syndrome and cerebral vasoconstrictive disorders. However, serotonin syndrome with 5-HTP has not yet been reported in humans. Monitor patients for signs of serotonin syndrome and other serotonergic side effects if using 5-HTP with serotonergic drugs.

Likelihood Possible Evidence D
L-5-Hydroxytryptophan full monograph & interactions

L-Tryptophan2 drug types · 394 drugs

Cns Depressants

Theoretically, concomitant use of L-tryptophan with CNS depressants might cause additive sedative effects.
Clinical research shows that L-tryptophan can cause fatigue and drowsiness.

Likelihood Probable Evidence B
Serotonergic Drugs

Theoretically, combining L-tryptophan with serotonergic drugs might cause additive serotonergic effects.
L-tryptophan is a precursor to serotonin. Theoretically, combining serotonergic drugs with L-tryptophan might increase the risk of serotonergic side effects, including serotonin syndrome and cerebral vasoconstrictive disorders.

Likelihood Possible Evidence D
L-Tryptophan full monograph & interactions

Magnesium15 drug types · 295 drugs

Levodopa/Carbidopa (Sinemet)

Magnesium can reduce the bioavailability of levodopa/carbidopa.
Clinical research in healthy volunteers shows that taking magnesium oxide 1000 mg with levodopa 100 mg/carbidopa 10 mg reduces the area under the curve (AUC) of levodopa by 35% and of carbidopa by 81%. In vitro and animal research shows that magnesium produces an alkaline environment in the digestive tract, which might lead to degradation and reduced bioavailability of levodopa/carbidopa.

Likelihood Probable Evidence B
Aminoglycoside Antibiotics

Concomitant use of aminoglycoside antibiotics and magnesium can increase the risk for neuromuscular weakness.
Both aminoglycosides and magnesium reduce presynaptic acetylcholine release, which can lead to neuromuscular blockade and possible paralysis. This is most likely to occur with high doses of magnesium given intravenously.

Likelihood Possible Evidence D
Antacids

Use of acid reducers may reduce the laxative effect of magnesium oxide.
A retrospective analysis shows that, in the presence of H2 receptor antagonists (H2RAs) or proton pump inhibitors (PPIs), a higher dose of magnesium oxide is needed for a laxative effect. This may also occur with antacids. Under acidic conditions, magnesium oxide is converted to magnesium chloride and then to magnesium bicarbonate, which has an osmotic laxative effect. By reducing acidity, antacids may reduce the conversion of magnesium oxide to the active bicarbonate salt.

Likelihood Possible Evidence D
Bictegravir/Emtricitabine/Tenofovir Alafenamide (Biktarvy)

Magnesium might decrease levels of bictegravir/emtricitabine/tenofovir alafenamide by reducing its absorption.
Advise patients that bictegravir/emtricitabine/tenofovir alafenamide should be taken at least 2 hours before or 6 hours after magnesium containing products.

Likelihood Probable Evidence D
Bisphosphonates

Magnesium can decrease absorption of bisphosphonates.
Cations, including magnesium, can decrease bisphosphonate absorption. Advise patients to separate doses of magnesium and these drugs by at least 2 hours.

Likelihood Probable Evidence B
Calcium Channel Blockers

Magnesium can have additive effects with calcium channel blockers, although evidence is conflicting.
Magnesium inhibits calcium entry into smooth muscle cells and may therefore have additive effects with calcium channel blockers. Severe hypotension and neuromuscular blockades may occur when nifedipine is used with intravenous magnesium, although some contradictory evidence suggests that concurrent use of magnesium with nifedipine does not increase the risk of neuromuscular weakness. High doses of magnesium could theoretically have additive effects with other calcium channel blockers.

Likelihood Possible Evidence D
Digoxin

Magnesium salts may reduce absorption of digoxin.
Clinical evidence suggests that treatment with oral magnesium hydroxide or magnesium trisilicate reduces absorption of digoxin from the intestines. This may reduce the blood levels of digoxin and decrease its therapeutic effects.

Likelihood Possible Evidence B
Potassium-Sparing Diuretics

Potassium-sparing diuretics decrease excretion of magnesium, possibly increasing magnesium levels.
Potassium-sparing diuretics also have magnesium-sparing properties, which can counteract the magnesium losses associated with loop and thiazide diuretics. Theoretically, increased magnesium levels could result from concomitant use of potassium-sparing diuretics and magnesium supplements.

Likelihood Probable Evidence D
Quinolone Antibiotics

Magnesium decreases absorption of quinolones.
Magnesium can form insoluble complexes with quinolones and decrease their absorption. Advise patients to take these drugs at least 2 hours before, or 4 to 6 hours after, magnesium supplements.

Likelihood Probable Evidence D
Skeletal Muscle Relaxants

Parenteral magnesium alters the pharmacokinetics of skeletal muscle relaxants, increasing their effects and accelerating the onset of effect.
Parenteral magnesium shortens the time to onset of skeletal muscle relaxants by about 1 minute and prolongs the duration of action by about 2 minutes. Magnesium potentiates the effects of skeletal muscle relaxants by decreasing calcium-mediated release of acetylcholine from presynaptic nerve terminals, reducing postsynaptic sensitivity to acetylcholine, and having a direct effect on the membrane potential of myocytes. Magnesium also has vasodilatory actions and increases cardiac output, allowing a greater amount of muscle relaxant to reach the motor end plate. A clinical study found that low-dose rocuronium (0.45 mg/kg), when given after administration of magnesium 30 mg/kg over 10 minutes, has an accelerated onset of effect, which matches the onset of effect seen with a full-dose rocuronium regimen (0.6 mg/kg). In another clinical study, onset times for rocuronium doses of 0.3, 0.6, and 1.2 mg/kg were 86, 76, and 50 seconds, respectively, when given alone, but were reduced to 66, 44, and 38 seconds, respectively, when the doses were given after a 15-minute infusion of magnesium sulfate 60 mg/kg. Giving intraoperative intravenous magnesium sulfate, 50 mg/kg loading dose followed by 15 mg/kg/hour, reduces the onset time of rocuronium, enhances its clinical effects, reduces the dose of intraoperative opiates, and prolongs the spontaneous recovery time. It does not affect the activity of subsequently administered neostigmine.

Likelihood Probable Evidence A
Sulfonylureas

Magnesium increases the systemic absorption of sulfonylureas, increasing their effects and side effects.
Clinical research shows that administration of magnesium hydroxide with glyburide increases glyburide absorption, increases maximal insulin response by 35-fold, and increases the risk of hypoglycemia, when compared with glyburide alone. A similar interaction occurs between magnesium hydroxide and glipizide. The mechanism of this effect appears to be related to the elevation of gastrointestinal pH by magnesium-based antacids, increasing solubility and enhancing absorption of sulfonylureas.

Likelihood Probable Evidence B
Tetracycline Antibiotics

Magnesium decreases absorption of tetracyclines.
Magnesium can form insoluble complexes with tetracyclines in the gut and decrease their absorption and antibacterial activity. Advise patients to take these drugs 1 hour before or 2 hours after magnesium supplements.

Likelihood Probable Evidence D
Anticoagulant/Antiplatelet Drugs

Theoretically, magnesium may have antiplatelet effects, but the evidence is conflicting.
In vitro evidence shows that magnesium sulfate inhibits platelet aggregation, even at low concentrations. Some preliminary clinical evidence shows that infusion of magnesium sulfate increases bleeding time by 48% and reduces platelet activity. However, other clinical research shows that magnesium does not affect platelet aggregation, although inhibition of platelet-dependent thrombosis can occur.

Likelihood Unlikely Evidence B
Gabapentin (Neurontin)

Gabapentin absorption can be decreased by magnesium.
Clinical research shows that giving magnesium oxide orally along with gabapentin decreases the maximum plasma concentration of gabapentin by 33%, time to maximum concentration by 36%, and area under the curve by 43%. Advise patients to take gabapentin at least 2 hours before, or 4 to 6 hours after, magnesium supplements.

Likelihood Unlikely Evidence B
Sevelamer (Renagel, Renvela)

Sevelamer may increase serum magnesium levels.
In patients on hemodialysis, sevelamer use was associated with a 0.28 mg/dL increase in serum magnesium. The mechanism of this interaction remains unclear.

Likelihood Possible Evidence B
Magnesium full monograph & interactions

L-Glycine1 drug type · 1 drug

Clozapine (Clozaril)

Theoretically, glycine might decrease the effectiveness of clozapine.
One small clinical study in patients with schizophrenia shows that adding glycine to clozapine therapy worsens symptoms of schizophrenia when compared with clozapine alone. The mechanism of this interaction is unclear.

Likelihood Probable Evidence B
L-Glycine full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Sleep Nighttime Powder, from the product label.

youtheory

See all youtheory products
Name
Nutrawise
City
Irvine
State
CA
ZipCode
92618
Phone Number
1.888.271.8976
Web Address
youtheory.com
Pharmacist Counseling Corner

Sleep Nighttime Powder by youtheory: Common Questions

Does Sleep Nighttime Powder by youtheory interact with any medications?
Yes. Based on its ingredients, Sleep Nighttime Powder has a known interaction with 1,580 medications, including 254 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Sleep Nighttime Powder contains 6 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Is this product safe if I'm taking an antidepressant like sertraline or fluoxetine?
Both L-tryptophan and 5-HTP in this powder carry a Moderate interaction with antidepressants—they can increase serotonin levels, raising the risk of serotonin syndrome (agitation, confusion, rapid heart rate, muscle rigidity). You should not use this product without first speaking to your pharmacist or doctor, who can assess your specific medication and whether it's safe to combine.
Can I take this with sleep aids or pain medications that make me drowsy?
No, not without checking first. L-tryptophan has a Major-severity interaction with CNS depressants (sedatives, sleep medications, and opioids), meaning it can cause dangerous additive drowsiness and even breathing problems. L-5-HTP also carries a Moderate interaction with these drugs. Your pharmacist needs to review your exact medications before you use this powder.
What's the concern with L-tryptophan I've heard about?
In 1989, L-tryptophan from one contaminated manufacturer in Japan caused over 1,500 cases of a serious neurological disorder called eosinophilia-myalgia syndrome (EMS). About 95% of cases were traced to that one source. The FDA then limited L-tryptophan imports, and modern products are more carefully screened, but the historical event remains important to know.
Is this product okay during pregnancy?
The safety data on these ingredients during pregnancy are incomplete or advise caution. L-Tryptophan safety data advises against use during pregnancy. Magnesium is noted as needed in pregnancy but should only be used under a doctor's guidance. Glycine, 5-HTP, theanine, and melatonin all lack enough safety information; there isn't data to know either way. You should talk with your doctor or pharmacist before using this powder if you're pregnant or planning to become pregnant.
Will this interact with my blood thinner (warfarin) or aspirin?
Yes. Melatonin in this powder has a Moderate interaction with blood thinners and antiplatelet drugs like warfarin and aspirin—case reports describe changes in bleeding risk, though the mechanism is unclear. You need to check with your pharmacist before using this product.
What are the most common side effects I might notice?
Across these ingredients, the most common side effects are drowsiness, nausea, headache, and gastrointestinal upset (diarrhea, stomach pain). L-Tryptophan can cause belching, flatulence, and heartburn. Melatonin often causes dizziness. If you stop taking the product, most of these resolve quickly.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Not sure if Sleep Nighttime Powder is safe with your meds?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Sleep Nighttime Powder label
Go deeper

The Full Monographs Behind Sleep Nighttime Powder’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Glycine

Interacts with 1 drug

Glycine is a non-essential amino acid your body makes on its own and that also appears in protein-rich foods. It is most studied for improving sleep quality, where early research is promisin...

Read the full Glycine monograph → Herb & supplement monograph

L-tryptophan

Interacts with 394 drugs

L-tryptophan is an essential amino acid the body uses to make serotonin and melatonin, and people take it to support sleep and mood. The evidence for supplement use is limited and mixed, and...

Read the full L-tryptophan monograph → Herb & supplement monograph

Magnesium

Interacts with 295 drugs

Magnesium is an essential mineral your body needs for muscles, nerves, blood pressure, and many other functions, and supplements are useful for preventing or correcting deficiency. Some othe...

Read the full Magnesium monograph → Herb & supplement monograph

5-htp

Interacts with 398 drugs

5-HTP is a compound your body uses to make serotonin, and people take it as a supplement hoping to improve mood, sleep, and headaches. Some early research is promising, but the overall evide...

Read the full 5-htp monograph → Herb & supplement monograph

Theanine

Interacts with 565 drugs

Theanine (usually L-theanine) is an amino acid found naturally in tea leaves that many people take to feel calmer and less stressed without strong drowsiness. Early research suggests it may...

Read the full Theanine monograph → Herb & supplement monograph

Melatonin

Interacts with 1,461 drugs

Melatonin is a hormone your body makes naturally to help control your sleep-wake cycle, and the supplement form is widely used to help with sleep timing problems and jet lag. The evidence is...

Read the full Melatonin monograph →
Sources

Sources & How We Checked

Sleep Nighttime Powder's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 261 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Glycine 5 references
  1. Heresco-Levy U, Javitt DC, Ermilov M, et al. Efficacy of high-dose glycine in the treatment of enduring negative symptoms of schizophrenia. Arch Gen Psychiatry 1999;56:29-36.. PubMed
  2. Potkin SG, Jin Y, Bunney BG, Costa J, Gulasekaram B. Effect of clozapine and adjunctive high-dose glycine in treatment-resistant schizophrenia. Am J Psychiatry 1999;156:145-7.. PubMed
  3. Gusev EI, Skvortsova VI, Dambinova SA, et al. Neuroprotective effects of glycine for therapy of acute ischaemic stroke. Cerebrovasc Dis 2000;10:49-60. PubMed
  4. Inagawa K, Kawai N, Ono K, Sukegawa E, Tsubuku S, Takahashi M. Assessment of acute adverse effects of glycine ingestion at a high dose in human volunteers. Seikatsu Eisei. 2006; 50:27-32.
  5. Woods SW, Walsh BC, Hawkins KA, Miller TJ, Saksa JR, D'Souza DC, Pearlson GD, Javitt DC, McGlashan TH, Krystal JH. Glycine treatment of the risk syndrome for psychosis: report of two pilot studies. Eur Neuropsychopharmacol. 2013 Aug;23(8):931-40. PubMed

See these in context on the Glycine monograph →

L-tryptophan 18 references
  1. Messiha FS. Fluoxetine: adverse effects and drug-drug interactions. J Toxicol Clin Toxicol 1993;31:603-30. PubMed
  2. Devoe LD, Castillo RA, Searle NS. Maternal dietary substrates and human fetal biophysical activity. The effects of tryptophan and glucose on fetal breathing movements. Am J Obstet Gynecol 1986;155:135-9. DOI
  3. Lieberman HR, Corkin S, Spring BJ. The effects of dietary neurotransmitter precursors on human behavior. Am J Clin Nutr 1985;42:366-70. PubMed
  4. U. S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Nutritional Products, Labeling, and Dietary Supplements. Information Paper on L-Tryptophan and 5-hydroxy-L-tryptophan, February 2001.
  5. Sullivan EA, Kamb ML, Jones JL, et al. The natural history of eosinophilia-myalgia syndrome in a tryptophan-exposed cohort in South Carolina. Arch Intern Med 1996;156:973-9. DOI
  6. Philen RM, Hill RH, Flanders WD, et al. Tryptophan contaminants associated with eosinophilia-myalgia syndrome. Am J Epidemiol 1993;138:154-9. PubMed
  7. Bohme A, Wolter M, Hoelzer D. L-tryptophan-related eosinophilia-myalgia syndrome possibly associated with a chronic B-lymphocytic leukemia. Ann Hematol 1998;77:235-8. PubMed
  8. Singhal AB, Caviness VS, Begleiter AF, et al. Cerebral vasoconstriction and stroke after use of serotonergic drugs. Neurology 2002;58:130-3. PubMed
  9. Priori R, Conti F, Luan FL, et al. Chronic fatigue: a peculiar evolution of eosinophilia myalgia syndrome following treatment with L-tryptophan in four Italian adolescents. Eur J Pediatr 1994;153:344-6..
  10. Klein R, Berg PA. A comparative study on antibodies to nucleoli and 5-hydroxytryptamine in patients with fibromyalgia syndrome and tryptophan-induced eosinophilia-myalgia syndrome. Clin Investig 1994;72:541-9.. PubMed
  11. Simat TJ, Kleeberg KK, Muller B, Sierts A. Synthesis, formation, and occurrence of contaminants in biotechnologically manufactured L-tryptophan. Adv Exp Med Biol 1999;467:469-80.. PubMed
  12. Shaw K, Turner J, Del Mar C. Tryptophan and 5-hydroxytryptophan for depression. Cochrane Database Syst Rev 2002;(1):CD003198. PubMed
  13. Kilbourne EM, Philen RM, Kamb ML, Falk H. Tryptophan produced by Showa Denko and epidemic eosinophilia-myalgia syndrome. J Rheumatol Suppl 1996;46:81-8.
  14. Horwitz RI, Daniels SR. Bias or biology: evaluating the epidemiologic studies of L-tryptophan and the eosinophilia-myalgia syndrome. J Rheumatol Suppl 1996;46:60-72.
  15. Shapiro S. Epidemiologic studies of the association of L-tryptophan with the eosinophilia-myalgia syndrome: a critique. J Rheumatol Suppl 1996;46:44-58.
  16. Mayeno AN, Gleich GJ. The eosinophilia-myalgia syndrome: lessons from Germany. Mayo Clin Proc 1994;69:702-4. PubMed
  17. Carr L, Ruther E, Berg PA, Lehnert H. Eosinophilia-myalgia syndrome in Germany: an epidemiologic review. Mayo Clin Proc 1994;69:620-5. PubMed
  18. Ullrich SS, Fitzgerald PCE, Giesbertz P, Steinert RE, Horowitz M, Feinle-Bisset C. Effects of intragastric administration of tryptophan on the blood glucose response to a nutrient drink and energy intake, in lean and obese men. Nutrients 2018;10(4). pii: PubMed

See these in context on the L-tryptophan monograph →

Magnesium 82 references
  1. Rodin SM, Johnson BF. Pharmacokinetic interactions with digoxin. Clin Pharmacokinet 1988;15:227-44.
  2. Covington TR, et al. Handbook of Nonprescription Drugs. 11th ed. Washington, DC: American Pharmaceutical Association, 1996.
  3. Dahle LO, Berg G, Hammar M, et al. The effect of oral magnesium substitution on pregnancy-induced leg cramps. Am J Obstet Gynecol 1995;173:175-80. PubMed
  4. Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
  5. Peikert A, Wilimzig C, Kohne-Volland R. Prophylaxis of migraine with oral magnesium: results from a prospective, multi-center, placebo-controlled and double-blind randomized study. Cephalalgia 1996;16:257-63. PubMed
  6. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. Washington, DC: National Academy Press, 1999. Available at: http://books.nap.edu/books/0309063507/html/index.html.
  7. Birrer RB, Shallash AJ, Totten V. Hypermagnesemia-induced fatality following epsom salt gargles. J Emerg Med 2002;22:185-8. PubMed
  8. Ryan MP. Diuretics and potassium/magnesium depletion. Directions for treatment. Am J Med 1987;82:38-47.. PubMed
  9. Hollifield JW. Magnesium depletion, diuretics, and arrhythmias. Am J Med 1987;82:30-7.. PubMed
  10. Heidenreich O. Mode of action of conventional and potassium-sparing diuretics--aspects with relevance to Mg-sparing effects. Magnesium 1984;3:248-56..
  11. Pfaffenrath V, Wessely P, Meyer C, et al. Magnesium in the prophylaxis of migraine--a double-blind placebo-controlled study. Cephalalgia 1996;16:436-40.. PubMed
  12. Wang F, Van Den Eeden SK, Ackerson LM, et al. Oral magnesium oxide prophylaxis of frequent migrainous headache in children: a randomized, double-blind, placebo-controlled trial. Headache 2003;43:601-10.. PubMed
  13. Sompolinsky D, Samra Z. Influence of magnesium and manganese on some biological and physical properties of tetracycline. J Bacteriol 1972;110:468-76.. PubMed
  14. Jeyabalan A, Caritis SN. Pharmacologic inhibition of preterm labor. Clin Obstet Gynecol 2002;45:99-113. PubMed
  15. Mittendorf R, Dambrosia J, Pryde PG, et al. Association between the use of antenatal magnesium sulfate in preterm labor and adverse health outcomes in infants. Am J Obstet Gynecol 2002;186:1111-8.. PubMed
  16. Witlin AG, Sibai BM. Magnesium sulfate therapy in preeclampsia and eclampsia. Obstet Gynecol 1998;92:883-9.. DOI
  17. Crowther CA, Hiller JE, Doyle LW. Magnesium sulphate for preventing preterm birth in threatened preterm labour. Cochrane Database Syst Rev 2002;4:CD001060. . PubMed
  18. Davey MJ, Teubner D. A randomized controlled trial of magnesium sulfate, in addition to usual care, for rate control in atrial fibrillation. Ann Emerg Med 2005;45:347-53.. PubMed
  19. L'Hommedieu CS, Nicholas D, Armes DA, et al. Potentiation of magnesium sulfate--induced neuromuscular weakness by gentamicin, tobramycin, and amikacin. J Pediatr 1983;102:629-31..
  20. Dunn CJ, Goa KL. Risedronate: a review of its pharmacological properties and clinical use in resorptive bone disease. Drugs 2001;61:685-712..
  21. Kass L, Weekes J, Carpenter L. Effect of magnesium supplementation on blood pressure: a meta-analysis. Eur J Clin Nutr 2012;66:411-8. PubMed
  22. Koontz SL, Friedman SA, Schwartz ML. Symptomatic hypocalcemia after tocolytic therapy with magnesium sulfate and nifedipine. Am J Obstet Gynecol. 2004;190(6):1773-6. PubMed
  23. Snyder SW, Cardwell MS. Neuromuscular blockade with magnesium sulfate and nifedipine. Am J Obstet Gynecol. 1989;161(1):35-6. PubMed
  24. Waisman GD, Mayorga LM, Cámera MI, et al. Magnesium plus nifedipine: potentiation of hypotensive effect in preeclampsia? Am J Obstet Gynecol. 1988;159(2):308-9. PubMed
  25. Brown DD, Juhl RP. Decreased bioavailability of digoxin due to antacids and kaolin-pectin. N Engl J Med. 1976;295(19):1034-7. PubMed
  26. Allen MD, Greenblatt DJ, Harmatz JS, et al. Effect of magnesium--aluminum hydroxide and kaolin--pectin on absorption of digoxin from tablets and capsules. J Clin Pharmacol. 1981;21(1):26-30. PubMed
  27. Ravn HB, Vissinger H, Kristensen SD, et al. Magnesium inhibits platelet activity--an in vitro study. Thromb Haemost. 1996;76(1):88-93. DOI
  28. Ravn HB, Kristensen SD, Vissinger H, et al. Magnesium inhibits human platelets. Blood Coagul Fibrinolysis. 1996;7(2):241-4. PubMed
  29. Ravn HB, Vissinger H, Kristensen SD, et al. Magnesium inhibits platelet activity--an infusion study in healthy volunteers. Thromb Haemost. 1996;75(6):939-44. DOI
  30. Neuvonen PJ, Kivistö KT. The effects of magnesium hydroxide on the absorption and efficacy of two glibenclamide preparations. Br J Clin Pharmacol. 1991;32(2):215-20. PubMed
  31. Kivistö KT, Neuvonen PJ. Enhancement of absorption and effect of glipizide by magnesium hydroxide. Clin Pharmacol Ther. 1991;49(1):39-43. PubMed
  32. Neuvonen PJ, Kivistö KT. Enhancement of drug absorption by antacids. An unrecognised drug interaction. Clin Pharmacokinet. 1994;27(2):120-8. PubMed
  33. Shechter, M., Merz, C. N., Paul-Labrador, M., Meisel, S. R., Rude, R. K., Molloy, M. D., Dwyer, J. H., Shah, P. K., and Kaul, S. Beneficial antithrombotic effects of the association of pharmacological oral magnesium therapy with aspirin in coronary heart
  34. Ganzevoort, J. W., Hoogerwaard, E. M., and van der Post, J. A. [Hypocalcemic delirium due to magnesium sulphate therapy in a pregnant woman with pre-eclampsia]. Ned.Tijdschr.Geneeskd. 8-3-2002;146(31):1453-1456.
  35. Horner, S. M. Efficacy of intravenous magnesium in acute myocardial infarction in reducing arrhythmias and mortality. Meta-analysis of magnesium in acute myocardial infarction. Circulation 1992;86(3):774-779. PubMed
  36. Azria, E., Tsatsaris, V., Goffinet, F., Kayem, G., Mignon, A., and Cabrol, D. [Magnesium sulfate in obstetrics: current data]. J Gynecol.Obstet.Biol.Reprod.(Paris) 2004;33(6 Pt 1):510-517.
  37. Magee, L. A., Miremadi, S., Li, J., Cheng, C., Ensom, M. H., Carleton, B., Cote, A. M., and von Dadelszen, P. Therapy with both magnesium sulfate and nifedipine does not increase the risk of serious magnesium-related maternal side effects in women with p
  38. Henyan, N. N., Gillespie, E. L., White, C. M., Kluger, J., and Coleman, C. I. Impact of intravenous magnesium on post-cardiothoracic surgery atrial fibrillation and length of hospital stay: a meta-analysis. Ann.Thorac.Surg. 2005;80(6):2402-2406. PubMed
  39. Li, J., Zhang, Q., Zhang, M., and Egger, M. Intravenous magnesium for acute myocardial infarction. Cochrane.Database.Syst.Rev. 2007;(2):CD002755. PubMed
  40. Doyle, L. W., Crowther, C. A., Middleton, P., Marret, S., and Rouse, D. Magnesium sulphate for women at risk of preterm birth for neuroprotection of the fetus. Cochrane.Database.Syst.Rev. 2009;(1):CD004661. PubMed
  41. Han, S., Crowther, C. A., and Moore, V. Magnesium maintenance therapy for preventing preterm birth after threatened preterm labour. Cochrane.Database.Syst.Rev. 2010;(7):CD000940. PubMed
  42. Duley, L., Gulmezoglu, A. M., Henderson-Smart, D. J., and Chou, D. Magnesium sulphate and other anticonvulsants for women with pre-eclampsia. Cochrane.Database.Syst.Rev. 2010;(11):CD000025. PubMed
  43. Conde-Agudelo, A., Romero, R., and Kusanovic, J. P. Nifedipine in the management of preterm labor: a systematic review and metaanalysis. Am J Obstet.Gynecol. 2011;204(2):134-20. PubMed
  44. Wong, G. K., Boet, R., Poon, W. S., Chan, M. T., Gin, T., Ng, S. C., and Zee, B. C. Intravenous magnesium sulphate for aneurysmal subarachnoid hemorrhage: an updated systemic review and meta-analysis. Crit Care 2011;15(1):R52. PubMed
  45. Magee, L., Sawchuck, D., Synnes, A., and von, Dadelszen P. SOGC Clinical Practice Guideline. Magnesium sulphate for fetal neuroprotection. J Obstet.Gynaecol.Can. 2011;33(5):516-529.
  46. Doyle, L. W. Antenatal magnesium sulfate and neuroprotection. Curr Opin Pediatr 2012;24(2):154-159. PubMed
  47. McDonald, S. D., Lutsiv, O., Dzaja, N., and Duley, L. A systematic review of maternal and infant outcomes following magnesium sulfate for pre-eclampsia/eclampsia in real-world use. Int J Gynaecol.Obstet. 2012;118(2):90-96. PubMed
  48. Gordon, M., Naidoo, K., Akobeng, A. K., and Thomas, A. G. Osmotic and stimulant laxatives for the management of childhood constipation. Cochrane.Database.Syst.Rev. 2012;7:CD009118. PubMed
  49. Dodd, J. M., Crowther, C. A., and Middleton, P. Oral betamimetics for maintenance therapy after threatened preterm labour. Cochrane.Database.Syst.Rev. 2012;12:CD003927. PubMed
  50. Wu, X., Wang, C., Zhu, J., Zhang, C., Zhang, Y., and Gao, Y. Meta-analysis of randomized controlled trials on magnesium in addition to beta-blocker for prevention of postoperative atrial arrhythmias after coronary artery bypass grafting. BMC.Cardiovasc.D PubMed
  51. Thorp, J. M., Jr., Katz, V. L., Campbell, D., and Cefalo, R. C. Hypersensitivity to magnesium sulfate. Am.J.Obstet.Gynecol. 1989;161(4):889-890. PubMed
  52. Duley L and Gulmezoglu AM. Magnesium sulphate versus lytic cocktail for eclampsia. Cochrane Database of Systematic Reviews 2000;(3) PubMed
  53. Gibbins KJ, Browning KR, Lopes VV, Anderson BL, Rouse DJ. Evaluation of the clinical use of magnesium sulfate for cerebral palsy prevention. Obstet Gynecol 2013;121(2 Pt 1):235-40. PubMed
  54. Ji D. Oral magnesium sulfate causes perforation during bowel preparation for fiberoptic colonoscopy in patients with colorectal cancer. J Emerg Med 2012;43(4):716-7. PubMed
  55. Yagi T, Naito T, Mino Y, Umemura K, Kawakami J. Impact of concomitant antacid administration on gabapentin plasma exposure and oral bioavailability in healthy adult subjects. Drug Metab Pharmacokinet 2012;27(2):248-54. PubMed
  56. Yamasaki M, Funakoshi S, Matsuda S, Imazu T, Takeda Y, Murakami T, Maeda Y. Interaction of magnesium oxide with gastric acid secretion inhibitors in clinical pharmacotherapy. Eur J Clin Pharmacol 2014;70(8):921-4. PubMed
  57. Choi ES, Jeong WJ, Ahn SH, Oh AY, Jeon YT, Do SH. Magnesium sulfate accelerates the onset of low-dose rocuronium in patients undergoing laryngeal microsurgery. J Clin Anesth. 2017 Feb;36:102-106. PubMed
  58. Ikee R, Toyoyama T, Endo T, Tsunoda M, Hashimoto N. Impact of sevelamer hydrochloride on serum magnesium concentrations in hemodialysis patients. Magnes Res. 2016 Apr 1;29(4):184-90. PubMed
  59. Miller ES, Sakowicz A, Leger E. Lange E, Yee LM. The association between receipt of intrapartum magnesium and postpartum hemorrhage. Am J Obstet Gynecol 2018;218(1 Suppl):S165.
  60. Rodríguez-Rubio L, Solis Garcia Del Pozo J, Nava E, Jordán J. Interaction between magnesium sulfate and neuromuscular blockers during the perioperative period. A systematic review and meta-analysis. J Clin Anesth. 2016;34:524-34. PubMed
  61. Brown RS. Magnesium Sulfate: Another Cause of a Solute Diuresis. Am J Kidney Dis. 2017;69(4):550-551. PubMed
  62. Park H, Qin R, Smith TJ, et al. North Central Cancer Treatment Group N10C2 (Alliance): a double-blind placebo-controlled study of magnesium supplements to reduce menopausal hot flashes. Menopause. 2015;22(6):627-32. PubMed
  63. Sakanoue M, Sanada J, Kanekura T. Skin eruption elicited by magnesium oxide (Maglax). J Dermatol. 2016;43(2):221-2.
  64. Iwamuro M, Saito S, Yoshioka M, et al. A Magnesium Oxide Bezoar. Intern Med. 2018;57(21):3087-3091. PubMed
  65. Vilchez G, Dai J, Kumar K, Mundy D, Kontopoulos E, Sokol RJ. Racial/ethnic disparities in magnesium sulfate neuroprotection: a subgroup analysis of a multicenter randomized controlled trial. J Matern Fetal Neonatal Med. 2018;31(17):2304-2311. PubMed
  66. Drug Safety Communication: FDA Recommends Against Prolonged Use of Magnesium Sulfate to Stop Pre-term Labor Due to Bone Changes in Exposed Babies. U.S. Food and Drug Administration (FDA), May 30, 2013. https://www.fda.gov/downloads/Drugs/DrugSafety/UCM353
  67. Committee Opinion: Magnesium Sulfate Use in Obstetrics. The American College of Obstetricians and Gynecologists Committee on Obstetric Practice Society for Maternal-Fetal Medicine, Number 652, January 2016. https://www.acog.org/Clinical-Guidance-and-Publi
  68. Kashihara Y, Terao Y, Yoda K, et al. Effects of magnesium oxide on pharmacokinetics of L-dopa/carbidopa and assessment of pharmacodynamic changes by a model-based simulation. Eur J Clin Pharmacol. 2019;75(3):351-361. PubMed
  69. Shepherd E, Salam RA, Manhas D, et al. Antenatal magnesium sulphate and adverse neonatal outcomes: A systematic review and meta-analysis. PLoS Med. 2019;16(12):e1002988. PubMed
  70. Hong JY, Hong JY, Choi YS, et al. Antenatal magnesium sulfate treatment and risk of necrotizing enterocolitis in preterm infants born at less than 32 weeks of gestation. Sci Rep. 2020;10(1):12826. PubMed
  71. Schuh S, Sweeney J, Rumantir M, et al. Effect of nebulized magnesium vs placebo added to albuterol on hospitalization among children with refractory acute asthma treated in the emergency department: a randomized clinical trial. JAMA. 2020;324(20):2038-20 PubMed
  72. Almeida CED, Carvalho LR, Andrade CVC, Nascimento PD Jr, Barros GAM, Modolo NSP. Effects of magnesium sulphate on the onset time of rocuronium at different doses: a randomized clinical trial. Braz J Anesthesiol. 2021;71(5):482-8. PubMed
  73. Gochi Valdovinos A, Arriaga-Redondo M, Dejuan Bitriá E, Pérez Rodríguez I, Márquez Isidro E, Blanco Bravo D. Prenatal therapy with magnesium sulphate and intestinal obstruction due to meconium in preterm newborns. An Pediatr (Engl Ed). 2022 Feb;96(2):138- PubMed
  74. Iio K, Kondo E, Shibata E, et al. Long-term tocolysis with magnesium sulfate as a risk factor for low bone mass: a case series. J Med Cases. 2022 Feb;13(2):47-50. PubMed
  75. Eiraku K, Uozumi Y, Hieda M, Maruyama T, Nomura H. A senile case of heart failure associated with hypermagnesemia induced by magnesium-containing laxative agent. Geriatr Gerontol Int. 2022;22(10):897-899.
  76. Enayati A, Gin JH, Sajeev JK, et al. Efficacy of intravenous magnesium for the management of non-post operative atrial fibrillation with rapid ventricular response: A systematic review and meta-analysis. J Cardiovasc Electrophysiol 2023;34(5):1286-1295. PubMed
  77. Su YH, Luo DC, Pang Y. Effects of intraoperative Magnesium sulfate infusion on emergency agitation during general anesthesia in patients undergoing radical mastectomy: a randomized controlled study. BMC Anesthesiol 2023;23(1):326. PubMed
  78. Han J, Park HY, Shin HJ, Chung SH, Do SH. Effects of magnesium sulphate on neostigmine-induced recovery from moderate neuromuscular blockade with rocuronium: a randomized controlled trial. Magnes Res 2023;36(2):31-39. PubMed
  79. Lee AT, Cordova JC, Jamplis RP, Pomicter GR. Posterior Reversible Encephalopathy Syndrome and Eclampsia in the Setting of Magnesium Toxicity: A Case Report. A A Pract 2023;17(11):e01726. PubMed
  80. Darmawan D, Rengganis I, Rumende CM, et al. Effectiveness and Safety of Nebulized Magnesium as Last Line Treatment in Adults with Acute Asthma Attack: A Systematic Review and Meta-Analysis. Acta Med Indones 2024;56(1):3-12.
  81. Shepherd ES, Goldsmith S, Doyle LW, et al. Magnesium sulphate for women at risk of preterm birth for neuroprotection of the fetus. Cochrane Database Syst Rev 2024;5(5):CD004661. PubMed
  82. US Food and Drug Administration (FDA). Biktarvy Prescribing Information. October 2024. Available at: https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/210251Orig1s020lbl.pdf. Accessed July 16, 2025.

See these in context on the Magnesium monograph →

5-htp 32 references
  1. Birdsall TC. 5-Hydroxytryptophan: A Clinically-Effective Serotonin Precursor. Altern Med Rev 1998;3:271-80.
  2. Michelson D, Page SW, Casey R, et al. An eosinophilia-myalgia syndrome related disorder associated with exposure to L-5-hydroxytryptophan. J Rheumatol 1994;21:2261-5.
  3. Cangiano C, Ceci F, Cancino A, et al. Eating behavior and adherence to dietary prescriptions in obese adult subjects treated with 5-hydroxytryptophan. Am J Clin Nutr 1992;56:863-7. PubMed
  4. U.S. Food and Drug Administration. Impurities confirmed in dietary supplement 5-hydroxy-L-tryptophan. FDA Talk Paper, August 31, 1998; T98-48.
  5. Sternberg EM, Van Woert MH, Young SN, et al. Development of a scleroderma-like illness during therapy with L-5-hydroxytryptophan and carbidopa. N Engl J Med 1980;303:782-7. PubMed
  6. Poldinger W, Calanchini B, Schwarz W. A functional-dimensional approach to depression: serotonin deficiency as a target syndrome in a comparison of 5-hydroxytryptophan and fluvoxamine. Psychopathology 1991;24:53-81.
  7. Ribeiro CA. L-5-Hydroxytryptophan in the prophylaxis of chronic tension-type headache: a double-blind, randomized, placebo-controlled study. Headache 2000;40:451-6.
  8. U. S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Nutritional Products, Labeling, and Dietary Supplements. Information Paper on L-Tryptophan and 5-hydroxy-L-tryptophan, February 2001.
  9. Singhal AB, Caviness VS, Begleiter AF, et al. Cerebral vasoconstriction and stroke after use of serotonergic drugs. Neurology 2002;58:130-3. PubMed
  10. Johnson KL, Klarskov K, Benson LM, et al. Presence of peak X and related compounds: the reported contaminant in case related 5-hydroxy-L-tryptophan associated with eosinophilia-myalgia syndrome. J Rheumatol 1999;26:2714-7.
  11. Takahashi S, Kondo H, Kato N. Effect of l-5-hydroxytryptophan on brain monoamine metabolism and evaluation of its clinical effect in depressed patients. J Psychiatr Res 1975;12:177-87. PubMed
  12. Iovieno, N., Dalton, E. D., Fava, M., and Mischoulon, D. Second-tier natural antidepressants: review and critique. J Affect.Disord. 2011;130(3):343-357. PubMed
  13. den Boer JA, Westenberg HG. Behavioral, neuroendocrine, and biochemical effects of 5-hydroxytryptophan administration in panic disorder. Psychiatry Res 1990;31:267-78. PubMed
  14. Jangid P, Malik P, Singh P, Sharma M, Gulia AK. Comparative study of efficacy of l-5-hydroxytryptophan and fluoxetine in patients presenting with first depressive episode. Asian J Psychiatr 2013;6:29-34. PubMed
  15. Ceci F, Cangiano C, Cairella M, et al. The effects of oral 5-hydroxytryptophan administration on feeding behavior in obese adult female subjects. J Neural Transm 1989;76:109-17. PubMed
  16. Angst J, Woggon B, Schoepf J. The treatment of depression with L-5-hydroxytryptophan versus imipramine. Results of two open and one double-blind study. Arch Psychiatr Nervenkr 1977;224:175-86. DOI
  17. Titus F, Dávalos A, Alom J, Codina A. 5-Hydroxytryptophan versus methysergide in the prophylaxis of migraine. Randomized clinical trial. Eur Neurol 1986;25:327-9. PubMed
  18. De Benedittis G, Massei R. Serotonin precursors in chronic primary headache. A double-blind cross-over study with L-5-hydroxytryptophan vs. placebo. J Neurosurg Sci 1985;29:239-48.
  19. Van Woert, M. H., Rosenbaum, D., Howieson, J., and Bowers, M. B., Jr. Long-term therapy of myoclonus and other neurologic disorders with L-5- hydroxytryptophan and carbidopa. N Engl J Med 1-13-1977;296(2):70-75. PubMed
  20. Wyatt, R. J., Vaughan, T., Galanter, M., Kaplan, J., and Green, R. Behavioral changes of chronic schizophrenic patients given L-5- hydroxytryptophan. Science 9-22-1972;177(54):1124-1126. PubMed
  21. Chase, T. N., Ng, L. K., and Watanabe, A. M. Parkinson's disease. Modification by 5-hydroxytryptophan. Neurology 1972;22(5):479-484.
  22. van Hiele LJ. l-5-Hydroxytryptophan in depression: the first substitution therapy in psychiatry? The treatment of 99 out-patients with 'therapy-resistant' depressions. Neuropsychobiology 1980;6:230-40. PubMed
  23. Pranzatelli, M. R., Tate, E., Huang, Y., Haas, R. H., Bodensteiner, J., Ashwal, S., and Franz, D. Neuropharmacology of progressive myoclonus epilepsy: response to 5- hydroxy-L-tryptophan. Epilepsia 1995;36(8):783-791. PubMed
  24. Trouillas P, Serratrice G, Laplane D, et al. Levorotatory form of 5-hydroxytryptophan in Friedreich's ataxia. Results of a double-blind drug-placebo cooperative study. Arch Neurol 1995;52:456-60. PubMed
  25. Bastard, J., Truelle, J. L., and Emile, J. [Effectiveness of 5 hydroxy-tryptophan in Parkinson's disease]. Nouv Presse Med 9-11-1976;5(29):1836-1837.
  26. Auffret, M., Comte, H., and Bene, J. Eosinophilia-myalgia syndrome induced by L-5 hydroxytryptophane: about three cases. Fund Clin Pharmacol 2013;Suppl 1(120):poster P2-204.
  27. Wyatt, R. J., Vaughan, T., Kaplan, J., Galanter, M., and Green, R. 5-Hydroxytryptophan and chronic schizophrenia. In: Barchas J and Usdin E. Serotonin and Behavior. New York: Acedemic Press;1973.
  28. Das YT, Bagchi M, Bagchi D, Preuss HG. Safety of 5-hydroxy-L-tryptophan. Toxicol Lett 2004;150:111-22. PubMed
  29. Pardo JV. Mania following addition of hydroxytryptophan to monoamine oxidase inhibitor. Gen Hosp Psychiatry 2012;34(1):102.e13-4. PubMed
  30. Michelson D, Page SW, Casey R, et al. An eosinophilia-myaligia syndrome related disorder associated with exposure to l-5-hydroxytryptophan. J Rheumatol 1994;21(12):2261-5.
  31. Yousefzadeh F, Sahebolzamani E, Sadri A, et al. 5-Hydroxytryptophan as adjuvant therapy in treatment of moderate to severe obsessive-compulsive disorder: a double-blind randomized trial with placebo control. Int Clin Psychopharmacol. 2020;35(5):254-262. PubMed
  32. Maffei ME. 5-Hydroxytryptophan (5-HTP): Natural Occurrence, Analysis, Biosynthesis, Biotechnology, Physiology and Toxicology. Int J Mol Sci. 2020;22(1):181. PubMed

See these in context on the 5-htp monograph →

Theanine 6 references
  1. Yokogoshi H, Kobayashi M. Hypotensive effect of gamma-glutamylethylamide in spontaneously hypertensive rats. Life Sci 1998;62:1065-8.
  2. Haskell, C. F., Kennedy, D. O., Milne, A. L., Wesnes, K. A., and Scholey, A. B. The effects of L-theanine, caffeine and their combination on cognition and mood. Biol.Psychol. 2008;77(2):113-122. PubMed
  3. Yokogoshi, H., Kato, Y., Sagesaka, Y. M., Takihara-Matsuura, T., Kakuda, T., and Takeuchi, N. Reduction effect of theanine on blood pressure and brain 5-hydroxyindoles in spontaneously hypertensive rats. Biosci.Biotechnol.Biochem. 1995;59(4):615-618. PubMed
  4. Lyon MR, Kapoor MP, Juneja LR. The effects of L-theanine (Suntheanine®) on objective sleep quality in boys with attention deficit hyperactivity disorder (ADHD): a randomized, double-blind, placebo-controlled clinical trial. Altern Med Rev. 2011;16(4):348-
  5. Hidese S, Ota M, Wakabayashi C, et al. Effects of chronic l-theanine administration in patients with major depressive disorder: an open-label study. Acta Neuropsychiatr 2017;29(2):72-9.
  6. Tsuchiya T, Honda H, Oikawa M, et al. Oral administration of the amino acids cystine and theanine attenuates the adverse events of S-1 adjuvant chemotherapy in gastrointestinal cancer patients. Int J Clin Oncol 2016;21(6):1085-90. PubMed

See these in context on the Theanine monograph →

Melatonin 118 references
  1. Voordouw BC, Euser R, Verdonk RE, et al. Melatonin and melatonin-progestin combinations alter pituitary-ovarian function in women and can inhibit ovulation. J Clin Endocrinol Metab 1992;74:108-17. DOI
  2. Ellis CM, Lemmens G, Parkes JD. Melatonin and insomnia. J Sleep Res 1996;5:61-5. PubMed
  3. Petrie K, Dawson AG, Thompson L, Brook R. A double-blind trial of melatonin as a treatment for jet lag in international cabin crew. Biol Psychiatr 1993;33:526-30. PubMed
  4. Claustrat B, Brun J, David M, et al. Melatonin and jet lag: confirmatory result using a simplified protocol. Biol Psychiatr 1992;32:705-11.
  5. Fauteck J, Schmidt H, Lerchl A, et al. Melatonin in epilepsy: first results of replacement therapy and first clinical results. Biol Signals Recept 1999;8:105-10. PubMed
  6. Arangino S, Cagnacci A, Angiolucci M, et al. Effects of melatonin on vascular reactivity, catecholamine levels, and blood pressure in healthy men. Am J Cardiol 1999;83:1417-9. PubMed
  7. Pierce A. The American Pharmaceutical Association Practical Guide to Natural Medicines. New York: The Stonesong Press, 1999:19.
  8. Lancioni GE, O'Reilly MF, Basili G. Review of strategies for treating sleep problems in persons with severe or profound mental retardation or multiple handicaps. Am J Ment Retard 1999;104:170-86. PubMed
  9. Carman JS, Post RM, Buswell R, et al. Negative effects of melatonin on depression. Am J Psychiatry 1976;133:1181-1186. PubMed
  10. Hartter S, Grozinger M, Weigmann H, et al. Increased bioavailability of oral melatonin after fluvoxamine coadministration. Clin Pharmacol Ther 2000;67:1-6.
  11. Fetrow CW, Avila JR. Professional's Handbook of Complementary & Alternative Medicines. 1st ed. Springhouse, PA: Springhouse Corp., 1999.
  12. Lusardi P, et al. Cardiovascular effects of melatonin in hypertensive patients well controlled by nifedipine: a 24-hour study. Br J Clin Pharmacol 2000;49:423-7. PubMed
  13. von Bahr C, Ursing C, Yasui N, et al. Fluvoxamine but not citalopram increases serum melatonin in healthy subjects – an indication that cytochrome P450 CYP1A2 and CYP2C19 hydroxylate melatonin. Eur J Clin Pharmacol 2000;56:123-7.
  14. Grozinger M, Hartter S, Wang X, et al. Fluvoxamine strongly inhibits melatonin metabolism in a patient with low-amplitude melatonin profile. Arch Gen Psychiatry 2000 Aug;57:812-3. PubMed
  15. Lissoni P, Barni S, Mandala M, et al. Decreased toxicity and increased efficacy of cancer chemotherapy using the pineal hormone melatonin in metastatic solic tumor patients with poor clinical status. Eur J Cancer 1999;35:1688-92.
  16. Sheldon SH. Pro-convulsant effects of oral melatonin in neurologically disabled children. Lancet 1998;351:1254. PubMed
  17. Hartter S, Grozinger M, Weigmann H, et al. Increased bioavailability of oral melatonin after fluvoxamine coadministration. Clin Pharmacol Ther 2000;67:1-6.
  18. Wright KP Jr, Myers BL, Plenzler SC, et al. Acute effects of bright light and caffeine on nighttime melatonin and temperature levels in women taking and not taking oral contraceptives. Brain Res 2000;873:310-7.
  19. Herxheimer A, Petrie KJ. Melatonin for preventing and treating jet lag. Cochrane Database Syst Rev 2001;(1):CD001520.
  20. Briggs, Freeman, Yafee. Update Drugs in Pregnancy and Lactation. Lippincott Williams & Wilkins, 2001.
  21. Suhner A, Schlagenhauf P, Johnson R, et al. Comparative study to determine the optimal melatonin dosage form for the alleviation of jet lag. Chronobiol Int 1998;15:655-66. PubMed
  22. Herxheimer A, Petrie KJ. Melatonin for the prevention and treatment of jet lag. Cochrane Database Syst Rev 2002;2:CD001520. PubMed
  23. Munoz-Hoyos A, Sanchez-Forte M, Molina-Carballo A, et al. Melatonin's role as an anticonvulsant and neuronal protector: experimental and clinical evidence. J Child Neurol 1998;13:501-9.. PubMed
  24. Sandyk R, Tsagas N, Anninos PA. Melatonin as a proconvulsive hormone in humans. Int J Neurosci 1992;63:125-35.. PubMed
  25. Golombek DA, Escolar E, Burin LJ, et al. Chronopharmacology of melatonin: inhibition by benzodiazepine antagonism. Chronobiol Int 1992;9:124-31.. PubMed
  26. Smits MG, Nagtegaal EE, van der Heijden J, et al. Melatonin for chronic sleep onset insomnia in children: a randomized placebo-controlled trial. J Child Neurol 2001;16:86-92.. PubMed
  27. Cagnacci A, Arangino S, Renzi A, et al. Influence of melatonin administration on glucose tolerance and insulin sensitivity of postmenopausal women. Clin Endocrinol (Oxf) 2001;54:339-46.. PubMed
  28. Williamson BL, Tomlinson AJ, Naylor S, Gleich GJ. Contaminants in commercial preparations of melatonin. Mayo Clin Proc 1997;72:1094-5. PubMed
  29. Williamson BL, Tomlinson AJ, Mishra PK, et al. Structural characterization of contaminants found in commercial preparations of melatonin: similarities to case-related compounds from L-tryptophan associated with eosinophilia-myalgia syndrome. Chem Res To
  30. Stewart LS. Endogenous melatonin and epileptogenesis: facts and hypothesis. Int J Neurosci 2001;107:77-85.. PubMed
  31. Molina-Carballo A, Munoz-Hoyos A, Reiter RJ, et al. Utility of high doses of melatonin as adjunctive anticonvulsant therapy in a child with severe myoclonic epilepsy: two years' experience. J Pineal Res 1997;23:97-105.. PubMed
  32. Tjon Pian Gi CV, Broeren JP, Starreveld JS, A Versteegh FG. Melatonin for treatment of sleeping disorders in children with attention deficit/hyperactivity disorder: a preliminary open label study. Eur J Pediatr 2003;162:554-5. PubMed
  33. Secreto G, Chiechi LM, Amadori A, et al. Soy isoflavones and melatonin for the relief of climacteric symptoms: a multicenter, double-blind, randomized study. Maturitas 2004;47:11-20. PubMed
  34. Weiss MD, Wasdell MB, Bomben MM, et al. Sleep hygiene and melatonin treatment for children and adolescents with ADHD and initial insomnia. J Am Acad Child Adolesc Psychiatry 2006;45:512-9. DOI
  35. Saha L, Malhotra S, Rana S, et al. A preliminary study of melatonin in irritable bowel syndrome. J Clin Gastroenterol 2007;41:29-32. PubMed
  36. Hussain, SA, Khadim, HM, Khalaf, BH, et al. Effects of melatonin and zinc on glycemic control in type 2 diabetic patients poorly controlled with metformin. Saudi Med J 2006;27:1483-8. DOI
  37. Kadhim, HM, Ismail, SH, Hussein, KI, et al. Effects of melatonin and zinc on lipid profile and renal function in type 2 diabetic patients poorly controlled with metformin. J Pineal Res 2006;41:189-93. PubMed
  38. Mutluay R. Elbeg S. Karakus R. et al. The Impact of Melatonin on Glucose Homeostasis. Turkish Journal of Endocrinology and Metabolism 2009;13:52-55.
  39. Wright KP Jr, Badia P, Myers BL, et al. Caffeine and light effects on nighttime melatonin and temperature levels in sleep-deprived humans. Brain Res. 1997;747(1):78-84. PubMed
  40. Peuhkuri K, Sihvola N, Korpela R. Dietary factors and fluctuating levels of melatonin. Food Nutr Res. 2012;56. doi: 10.3402/fnr.v56i0.17252. Epub 2012 Jul 20. PubMed
  41. Gibb JW, Bush L, Hanson GR. Exacerbation of methamphetamine-induced neurochemical deficits by melatonin. J Pharmacol Exp Ther. 1997;283(2):630-5. DOI
  42. Sunami E, Usuda K, Nishiyama Y, et al. A preliminary study of fluvoxamine maleate on depressive state and serum melatonin levels in patients after cerebral infarction. Intern Med. 2012;51(10):1187-93. PubMed
  43. Babkoff, H., French, J., Whitmore, J., and Sutherlin, R. Single-dose bright light and/or caffeine effect on nocturnal performance. Aviat.Space Environ.Med. 2002;73(4):341-350.
  44. Rossignol, D. A. Novel and emerging treatments for autism spectrum disorders: a systematic review. Ann.Clin Psychiatry 2009;21(4):213-236. DOI
  45. Yeleswaram, K., Vachharajani, N., and Santone, K. Involvement of cytochrome P-450 isozymes in melatonin metabolism and clinical implications. J Pineal Res 1999;26(3):190-191. PubMed
  46. Jan, J. E., Connolly, M. B., Hamilton, D., Freeman, R. D., and Laudon, M. Melatonin treatment of non-epileptic myoclonus in children. Dev.Med Child Neurol. 1999;41(4):255-259. PubMed
  47. Edwards, B. J., Atkinson, G., Waterhouse, J., Reilly, T., Godfrey, R., and Budgett, R. Use of melatonin in recovery from jet-lag following an eastward flight across 10 time-zones. Ergonomics 2000;43(10):1501-1513. PubMed
  48. Cagnacci, A., Arangino, S., Angiolucci, M., Melis, G. B., Facchinetti, F., Malmusi, S., and Volpe, A. Effect of exogenous melatonin on vascular reactivity and nitric oxide in postmenopausal women: role of hormone replacement therapy. Clin Endocrinol (Oxf PubMed
  49. Wakatsuki, A., Okatani, Y., Ikenoue, N., Kaneda, C., and Fukaya, T. Effects of short-term melatonin administration on lipoprotein metabolism in normolipidemic postmenopausal women. Maturitas 4-20-2001;38(2):171-177. PubMed
  50. Kitajima, T., Kanbayashi, T., Saitoh, Y., Ogawa, Y., Sugiyama, T., Kaneko, Y., Sasaki, Y., Aizawa, R., and Shimisu, T. The effects of oral melatonin on the autonomic function in healthy subjects. Psychiatry Clin Neurosci. 2001;55(3):299-300. PubMed
  51. Calvo, J. R., Guerrero, J. M., Osuna, C., Molinero, P., and Carrillo-Vico, A. Melatonin triggers Crohn's disease symptoms. J Pineal Res 2002;32(4):277-278. PubMed
  52. Luboshitzky, R., Shen-Orr, Z., Nave, R., Lavi, S., and Lavie, P. Melatonin administration alters semen quality in healthy men. J Androl 2002;23(4):572-578. DOI
  53. Rufo-Campos, M. [Melatonin and epilepsy]. Rev Neurol. 2002;35 Suppl 1:S51-S58.
  54. Ursing, C., Wikner, J., Brismar, K., and Rojdmark, S. Caffeine raises the serum melatonin level in healthy subjects: an indication of melatonin metabolism by cytochrome P450(CYP)1A2. J.Endocrinol.Invest 2003;26(5):403-406. PubMed
  55. Smits, M. G., van Stel, H. F., van der, Heijden K., Meijer, A. M., Coenen, A. M., and Kerkhof, G. A. Melatonin improves health status and sleep in children with idiopathic chronic sleep-onset insomnia: a randomized placebo-controlled trial. J Am Acad.Chi PubMed
  56. Boeve, B. F., Silber, M. H., and Ferman, T. J. Melatonin for treatment of REM sleep behavior disorder in neurologic disorders: results in 14 patients. Sleep Med. 2003;4(4):281-284. PubMed
  57. Hartter, S., Nordmark, A., Rose, D. M., Bertilsson, L., Tybring, G., and Laine, K. Effects of caffeine intake on the pharmacokinetics of melatonin, a probe drug for CYP1A2 activity. Br.J.Clin.Pharmacol. 2003;56(6):679-682. PubMed
  58. Scheer, F. A., Van Montfrans, G. A., van Someren, E. J., Mairuhu, G., and Buijs, R. M. Daily nighttime melatonin reduces blood pressure in male patients with essential hypertension. Hypertension 2004;43(2):192-197. PubMed
  59. Buscemi, N., Vandermeer, B., Pandya, R., Hooton, N., Tjosvold, L., Hartling, L., Baker, G., Vohra, S., and Klassen, T. Melatonin for treatment of sleep disorders. Evid.Rep.Technol.Assess.(Summ.) 2004;(108):1-7.
  60. Cavallo, A., Ris, M. D., Succop, P., and Jaskiewicz, J. Melatonin treatment of pediatric residents for adaptation to night shift work. Ambul.Pediatr. 2005;5(3):172-177. PubMed
  61. Faber, M. S., Jetter, A., and Fuhr, U. Assessment of CYP1A2 activity in clinical practice: why, how, and when? Basic Clin Pharmacol Toxicol. 2005;97(3):125-134. PubMed
  62. Cagnacci, A., Cannoletta, M., Renzi, A., Baldassari, F., Arangino, S., and Volpe, A. Prolonged melatonin administration decreases nocturnal blood pressure in women. Am J Hypertens. 2005;18(12 Pt 1):1614-1618. PubMed
  63. Weekley, L. B. Melatonin-induced relaxation of rat aorta: interaction with adrenergic agonists. J Pineal Res 1991;11(1):28-34. PubMed
  64. Grossman, E., Laudon, M., Yalcin, R., Zengil, H., Peleg, E., Sharabi, Y., Kamari, Y., Shen-Orr, Z., and Zisapel, N. Melatonin reduces night blood pressure in patients with nocturnal hypertension. Am J Med 2006;119(10):898-902. PubMed
  65. van der Heijden, K. B., Smits, M. G., van Someren, E. J., Ridderinkhof, K. R., and Gunning, W. B. Effect of melatonin on sleep, behavior, and cognition in ADHD and chronic sleep-onset insomnia. J Am Acad.Child Adolesc.Psychiatry 2007;46(2):233-241. PubMed
  66. Klupinska, G., Poplawski, T., Drzewoski, J., Harasiuk, A., Reiter, R. J., Blasiak, J., and Chojnacki, J. Therapeutic effect of melatonin in patients with functional dyspepsia. J.Clin.Gastroenterol. 2007;41(3):270-274. PubMed
  67. Bjorvatn, B., Stangenes, K., Oyane, N., Forberg, K., Lowden, A., Holsten, F., and Akerstedt, T. Randomized placebo-controlled field study of the effects of bright light and melatonin in adaptation to night work. Scand.J Work Environ.Health 2007;33(3):204 PubMed
  68. Wirtz, P. H., Spillmann, M., Bartschi, C., Ehlert, U., and von Kanel, R. Oral melatonin reduces blood coagulation activity: a placebo-controlled study in healthy young men. J Pineal Res 2008;44(2):127-133. PubMed
  69. Bendz, L. M. and Scates, A. C. Melatonin treatment for insomnia in pediatric patients with attention-deficit/hyperactivity disorder. Ann.Pharmacother. 2010;44(1):185-191. PubMed
  70. Elkhayat, H. A., Hassanein, S. M., Tomoum, H. Y., Abd-Elhamid, I. A., Asaad, T., and Elwakkad, A. S. Melatonin and sleep-related problems in children with intractable epilepsy. Pediatr.Neurol. 2010;42(4):249-254. PubMed
  71. van Geijlswijk, I. M., van der Heijden, K. B., Egberts, A. C., Korzilius, H. P., and Smits, M. G. Dose finding of melatonin for chronic idiopathic childhood sleep onset insomnia: an RCT. Psychopharmacology (Berl) 2010;212(3):379-391. PubMed
  72. Wade AG, Ford I, Crawford G, et al. Nightly treatment of primary insomnia with prolonged release melatonin for 6 months: a randomized placebo controlled trial on age and endogenous melatonin as predictors of efficacy and safety. BMC Med 2010;8:51. PubMed
  73. Al-Aama, T., Brymer, C., Gutmanis, I., Woolmore-Goodwin, S. M., Esbaugh, J., and Dasgupta, M. Melatonin decreases delirium in elderly patients: a randomized, placebo-controlled trial. Int.J.Geriatr.Psychiatry 2011;26(7):687-694. PubMed
  74. Alstadhaug, K. B., Odeh, F., Salvesen, R., and Bekkelund, S. I. Prophylaxis of migraine with melatonin: a randomized controlled trial. Neurology 10-26-2010;75(17):1527-1532. PubMed
  75. Wade, A. G., Crawford, G., Ford, I., McConnachie, A., Nir, T., Laudon, M., and Zisapel, N. Prolonged release melatonin in the treatment of primary insomnia: evaluation of the age cut-off for short- and long-term response. Curr.Med.Res.Opin. 2011;27(1):87 PubMed
  76. van Geijlswijk, I. M., Korzilius, H. P., and Smits, M. G. The use of exogenous melatonin in delayed sleep phase disorder: a meta-analysis. Sleep 2010;33(12):1605-1614. PubMed
  77. Guenole, F., Godbout, R., Nicolas, A., Franco, P., Claustrat, B., and Baleyte, J. M. Melatonin for disordered sleep in individuals with autism spectrum disorders: systematic review and discussion. Sleep Med.Rev. 2011;15(6):379-387. PubMed
  78. Rossignol, D. A. and Frye, R. E. Melatonin in autism spectrum disorders: a systematic review and meta-analysis. Dev.Med.Child Neurol. 2011;53(9):783-792. PubMed
  79. Eryilmaz, O. G., Devran, A., Sarikaya, E., Aksakal, F. N., Mollamahmutoglu, L., and Cicek, N. Melatonin improves the oocyte and the embryo in IVF patients with sleep disturbances, but does not improve the sleeping problems. J.Assist.Reprod.Genet. 2011;28 PubMed
  80. Batioglu, A. S., Sahin, U., Gurlek, B., Ozturk, N., and Unsal, E. The efficacy of melatonin administration on oocyte quality. Gynecol.Endocrinol. 2012;28(2):91-93.
  81. Grossman, E., Laudon, M., and Zisapel, N. Effect of melatonin on nocturnal blood pressure: meta-analysis of randomized controlled trials. Vasc.Health Risk Manag. 2011;7:577-584. PubMed
  82. Nickelsen, T., Demisch, L., Demisch, K., Radermacher, B., and Schoffling, K. Influence of subchronic intake of melatonin at various times of the day on fatigue and hormonal levels: a placebo-controlled, double-blind trial. J Pineal Res 1989;6(4):325-334. PubMed
  83. Wright, J., Aldhous, M., Franey, C., English, J., and Arendt, J. The effects of exogenous melatonin on endocrine function in man. Clin Endocrinol (Oxf) 1986;24(4):375-382. PubMed
  84. Papavasiliou, P. S., Cotzias, G. C., Duby, S. E., Steck, A. J., Bell, M., and Lawrence, W. H. Melatonin and parkinsonism. JAMA 7-3-1972;221(1):88-89. DOI
  85. Middleton, B. A., Stone, B. M., and Arendt, J. Melatonin and fragmented sleep patterns. Lancet 8-24-1996;348(9026):551-552. PubMed
  86. Holliman, B. J. and Chyka, P. A. Problems in assessment of acute melatonin overdose. South.Med J 1997;90(4):451-453. PubMed
  87. Hong, Y. G. and Riegler, J. L. Is melatonin associated with the development of autoimmune hepatitis? J Clin Gastroenterol 1997;25(1):376-378. PubMed
  88. Cagnacci, A., Arangino, S., Angiolucci, M., Maschio, E., and Melis, G. B. Influences of melatonin administration on the circulation of women. Am J Physiol 1998;274(2 Pt 2):R335-R338. PubMed
  89. U.S.Food and Drug Administration. Special Nutritionals Adverse Events Monitoring System: registered case reports.
  90. Brueske V, Allen J, Kepic T, and et al. Melatonin inhibition of seizure activity in man [abstract]. Electroencephalog Clin Neurophysiol 1981;51:20P.
  91. Siddiqui MA, Nazmi AS, Karim S, and et al. Effect of melatonin and valproate in epilepsy and depression. Indian J Pharmacol 2001;33:378-381.
  92. Appleton RE, Jones AP, Gamble C, et al. The use of MElatonin in children with neurodevelopmental disorders and impaired sleep: a randomised, double-blind, placebo-controlled, parallel study (MENDS). Health Technol Assess. 2012;16(40):i-239. PubMed
  93. Bardazzi F, Placucci F, Neri I, D'Antuono A, Patrizi A. Fixed drug eruption due to melatonin. Acta Derm Venereol. 1998 Jan;78(1):69-70. PubMed
  94. Eckerberg B, Lowden A, Nagai R, Akerstedt T. Melatonin treatment effects on adolescent students' sleep timing and sleepiness in a placebo-controlled crossover study. Chronobiol Int. 2012;29(9):1239-48.
  95. Khezri MB, Merate H. The effects of melatonin on anxiety and pain scores of patients, intraocular pressure, and operating conditions during cataract surgery under topical anesthesia. Indian J Ophthalmol. 2013;61(7):319-24. PubMed
  96. Khezri MB, Oladi MR, Atlasbaf A. Effect of melatonin and gabapentin on anxiety and pain associated with retrobulbar eye block for cataract surgery: a randomized double-blind study. Indian J Pharmacol. 2013;45(6):581-6. PubMed
  97. Nishihara T, Hashimoto S, Ito K, et al. Oral melatonin supplementation improves oocyte and embryo quality in women undergoing in vitro fertilization-embryo transfer. Gynecol Endocrinol. 2014;30(5):359-62.
  98. De Bleecker JL, Lamont BH, Verstraete AG, Schelfhout VJ. Melatonin and painful gynecomastia. Neurology. 1999 Jul 22;53(2):435-6. PubMed
  99. Waldron DL, Bramble D, Gringras P. Melatonin: prescribing practices and adverse events. Arch Dis Child. 2005 Nov;90(11):1206-7. PubMed
  100. Chojnacki C, Walecka-Kapica E, Lokiec K, et al. Influence of melatonin on symptoms of irritable bowel syndrome in postmenopausal women. Endokrynol Pol. 2013;64(2):114-20.
  101. Kim MK, Park EA, Kim HJ, et al. Does supplementation of in-vitro culture medium with melatonin improve IVF outcome in PCOS? Reprod Biomed Online. 2013;26(1):22-9. PubMed
  102. Silman RE. Melatonin: a contraceptive for the nineties. Eur J Obstet Gynecol Reprod Biol. 1993;49(1-2):3-9. PubMed
  103. Briggs GG, Freeman RK, Forinash AB, Towers CV. Drugs in Pregnancy and Lactation. 11th ed. Philadelphia, PA: Wolters Kluwer, 2017.
  104. Onseng K, Johns NP, Khuayjarernpanishk T, et al. Beneficial Effects of Adjuvant Melatonin in Minimizing Oral Mucositis Complications in Head and Neck Cancer Patients Receiving Concurrent Chemoradiation. J Altern Complement Med 2017;23(12):957-63. PubMed
  105. Foster BC, Cvijovic K, Boon HS, et al. Melatonin Interaction Resulting in Severe Sedation. J Pharm Pharm Sci 2015;18(2):124-31. PubMed
  106. Gonçalves AL, Martini Ferreira A, Ribeiro RT, Zukerman E, Cipolla-Neto J, Peres MF. Randomised clinical trial comparing melatonin 3 mg, amitriptyline 25 mg and placebo for migraine prevention. J Neurol Neurosurg Psychiatry 2016;87(10):1127-32. PubMed
  107. Gringras P, Nir T, Breddy J, Frydman-Marom A, Findling RL. Efficacy and Safety of Pediatric Prolonged-Release Melatonin for Insomnia in Children With Autism Spectrum Disorder. J Am Acad Child Adolesc Psychiatry 2017;56(11):948-57.e4. PubMed
  108. Baandrup L, Lindschou J, Winkel P, Gluud C, Glenthoj BY. Prolonged-release melatonin versus placebo for benzodiazepine discontinuation in patients with schizophrenia or bipolar disorder: A randomised, placebo-controlled, blinded trial. World J Biol Psychi PubMed
  109. Lui MFG, Chow HKD, Wong WMK, Tsang WNW. Melatonin affects postural control in community-dwelling older adults while dual-tasking: a randomized observation study. J Aging Phys Act. 2018 May 29:1-24. PubMed
  110. Fallah R, Shoroki FF, Ferdosian F. Safety and efficacy of melatonin in pediatric migraine prophylaxis. Curr Drug Saf. 2015;10(2):132-5. PubMed
  111. Scheuer C, Pommergaard HC, Rosenberg J, Gogenur I. Effect of topical application of melatonin cream 12.5% on cognitive parameters: a randomized, placebo-controlled, double-blind crossover study in healthy volunteers. J Dermatolog Treat. 2016 Nov;27(6):488 PubMed
  112. Doosti-Irani A, Ostadmohammadi V, Mirhosseini N et al. The effects of melatonin supplementation on glycemic control: A systematic review and meta-analysis of randomized controlled trials. Horm Metab Res. 2018;50(11):783-790. PubMed
  113. Farrokhian A, Tohidi M, Ahanchi NS, et al. Effect of bedtime melatonin administration in patients with type 2 diabetes: A triple-blind, placebo-controlled, randomized trial. Iran J Pharm Res. 2019;18(Suppl1):258-268.
  114. Hayashi M, Mishima K, Fukumizu M, et al. Melatonin treatment and adequate sleep hygiene interventions in children with autism spectrum disorder: A randomized controlled trial. J Autism Dev Disord 2021. PubMed
  115. Esmaeili A, Nassiri Toosi M, Taher M, et al. A pilot randomized, clinical trial of the anti-pruritus effect of melatonin in patients with chronic liver disease. Iran J Pharm Res 2021;20(2):462-472.
  116. Yan W, Li C, Song X, Zhou W, Chen Z. Prophylactic melatonin for delirium in critically ill patients: A systematic review and meta-analysis with trial sequential analysis. Medicine (Baltimore) 2022;101(43):e31411. PubMed
  117. Ameri A, Frouz Asadi M, Ziaei A, et al. Efficacy and safety of oral melatonin in patients with severe COVID-19: a randomized controlled trial. Inflammopharmacology 2023;31(1):265-274. PubMed
  118. Ha M, Yoon D, Lee CY, et al. Investigating the safety profiles of exogenous melatonin and associated adverse events: A pharmacovigilance study using WHO-VigiBase. J Pineal Res 2024;76(2):e12949. PubMed

See these in context on the Melatonin monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Supplement interaction checker › Check any supplement or product against your medications Drug–drug interactions › Check two or more of your medications against each other Browse medications A–Z › Every drug we've checked against herbs & supplements NDC & pricing lookup › Find a drug’s NDCs, packaging and costs Ask a pharmacist › Free, personal answer from our licensed team