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Dietary supplement

5-HTP (5-Hydroxytryptophan) 200 mg Ingredients & Drug Interactions

by Protocol For Life Balance

5-HTP (5-Hydroxytryptophan) 200 mg label
See full label image
Capsule Category: Other Combinations
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking 5-HTP (5-Hydroxytryptophan) 200 mg 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: Moderate

5-HTP (5-Hydroxytryptophan) 200 mg is a dietary supplement by Protocol For Life Balance with 6 active ingredients. Its ingredients are commonly taken for morning sickness in pregnancy, premenstrual syndrome (pms), preventing or treating b6 deficiency.Based on those ingredients, 1,045 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Niacin, 5-HTP, Vitamin B6. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against 5-HTP (5-Hydroxytryptophan) 200 mg by Protocol For Life Balance

Ask about any prescription or over-the-counter medication and we check it for interactions with 5-HTP (5-Hydroxytryptophan) 200 mg by Protocol For Life Balance — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of 5-HTP (5-Hydroxytryptophan) 200 mg by Protocol For Life Balance

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.

This product contains 6 active ingredients. The headline ingredient is 5-HTP (5-hydroxytryptophan), an amino acid precursor to serotonin that plays a role in mood and sleep regulation.

It's paired with supporting nutrients: vitamin B6, which helps your body use amino acids and produce neurotransmitters; niacin, a B vitamin involved in energy and DNA repair; glycine, another amino acid; taurine, a compound important for heart and muscle function; and inositol, a carbohydrate that may support insulin function and mood. The capsule also contains inactive ingredients—hypromellose, ascorbyl palmitate, and silicon dioxide—which serve as a capsule material and preservatives.

Does it work?

Moderate 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
Moderate

Some clinical evidence supports this product's ingredients for its stated purpose, but it isn't conclusive.

Why this rating?
  • The label markets this product for: supports mood and sleep regulation.
  • We looked for evidence on: Anxiety, Depression, Cognitive function, Sleep quality, Stress.
  • The strongest evidence on file: 5-htp is rated "Possibly Effective" for Depression (Natural Medicines).
  • Also on file: Inositol is rated "Possibly Ineffective" for Acute respiratory distress syndrome (ARDS), Anxiety, Depression.
  • Also on file: Inositol is rated "Insufficient Reliable Evidence To Rate" for Post-traumatic stress disorder (PTSD).

The effectiveness evidence varies by ingredient and condition. Vitamin B6 is effective for sideroblastic anemia and vitamin B6 deficiency, likely effective for lowering a metabolic marker called homocysteine, and possibly effective for pregnancy-related nausea and vomiting.

Niacin is likely effective for pellagra and possibly effective for certain HIV-related cholesterol problems and metabolic syndrome. For the other ingredients in this formula—5-HTP, glycine, taurine, and inositol—the evidence is mostly in the possibly effective to insufficient range for various conditions, and some show possibly ineffective ratings.

The product as a whole is not established in our data as effective for any single condition; you'd need to discuss with your doctor or pharmacist whether it's appropriate for your specific health goal.

The evidence, ingredient by ingredient Vitamin B6 Glycine 5-htp Niacin Taurine Inositol

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.

5-HTP is generally well tolerated short-term, but nausea, diarrhea, drowsiness, and headache occur commonly and appear dose-dependent. Vitamin B6 is safe at normal dietary and recommended supplement doses, but high doses over time can harm nerves and cause sensory numbness and tingling.

Niacin at standard doses causes flushing in up to 70% of users and can harm your liver, especially in sustained-release forms and at high doses. Glycine is generally well tolerated at typical doses but has limited long-term safety data.

Taurine is well tolerated for up to one year in typical doses, though long-term safety is uncertain. Inositol is generally well tolerated with mostly mild digestive side effects like diarrhea and gas.

For pregnancy: vitamin B6 and niacin are rated likely safe, inositol is possibly safe, but 5-HTP and glycine lack sufficient safety information—avoid during pregnancy without medical approval. For breastfeeding: vitamin B6 is rated likely safe and niacin is likely safe, but 5-HTP and glycine should be avoided, inositol's safety is unclear, and taurine data are insufficient.

Side effects, ingredient by ingredient Vitamin B6 Glycine 5-htp Niacin Taurine Inositol

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 6 of the 6 matched ingredients can interact with medications — Inositol, 5-htp, Niacin, Vitamin B6, Taurine, among others.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; diabetes medications; lithium; Parkinson's medications.
  • For scale: 1,046 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, have your pharmacist or doctor check if you use serotonergic drugs (antidepressants, certain migraine drugs, and others that raise serotonin)—major risk. Seizure medications phenytoin or phenobarbital may lose effectiveness.

Blood-pressure drugs, diabetes medications, cholesterol-lowering statins, gout medications, heart rhythm drugs like amiodarone, medications that harm the liver, blood thinners or antiplatelet drugs, bile acid sequestrants, carbidopa for Parkinson's, clozapine for schizophrenia, and lithium all carry documented moderate interactions. Run your specific medications through the checker on this page.

Check your own medication Run your meds through the checker above

The bottom line

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

This is a multi-ingredient formula that packs substantial drug interaction potential, especially with serotonergic medications, seizure drugs, blood-pressure and diabetes medications, statins, and several others. If you take any prescription or over-the-counter medications—particularly antidepressants, mood stabilizers, or chronic disease medications—check your exact medications with the tool on this page before you start.

Talk with your pharmacist or doctor about whether this product is right for you.

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 Jun 22, 2023.

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 5-HTP (5-Hydroxytryptophan) 200 mg, straight from the product label.

Brand Protocol For Life Balance
Barcode (UPC) 707359101081
Net contents 60 Veg Capsule(s)
Market status On market
Date entered into DSLD Jun 22, 2023
DSLD ID 292250
Product type Other Combinations
Supplement form Capsule
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Vegan, Vegetarian, Adult (18 - 50 Years), Women (not pregnant or lactating), Gluten Free, Dairy Free
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 5-HTP (5-Hydroxytryptophan) 200 mg by Protocol For Life Balance, 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:
1 Veg Capsule(s)
Maximum serving Sizes:
1 Veg Capsule(s)
Servings per container
60
UPC/BARCODE
707359101081
IngredientAmount% DV
Vitamin B62 mg118%
Glycine100 mg--
5-HTP200 mg--
Niacin20 mg125%
Taurine100 mg--
Inositol100 mg--

Other ingredients: Hypromellose, Ascorbyl Palmitate, Silicon Dioxide

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.
Suggested/Recommended/Usage/Directions

Suggested usage: Take 1 capsule 1 to 2 times daily, preferably on an empty stomach before bedtime, or as directed by your healthcare practitioner.

Formula

How it works: 5-HTP is the intermediate precursor in the natural synthesis of serotonin, a neurotransmitter that helps to regulate mood, appetite, and sleep/wake cycles. 5-HTP readily crosses the blood-brain barrier and clinical studies suggest that 5-HTP can support healthy serotonin levels. Serotonin is associated with a positive mood and provides a substrate for the production of melatonin. This formula includes B-vitamins as cofactors, and is further enhanced with glycine, taurine, and inositol.

With glycine, taurine & inositol

Precautions

Cautions/interactions: May cause mild, but transient GI discomfort. 5-HTP should be used with caution in combination with any serotonergic drug or herb, including SSRIs, MAOIs and St. John's wort. if you are taking any of these medications or if you are planning any surgical procedures, consult your healthcare practitioner prior to using this product. Not recommended for pregnant or nursing women.

Not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish or tree nut ingredients. Produced in a GMP facility that processes other ingredients containing these allergens.

Individuals with a history of cardiac conditions, use only under the direction of your healthcare practitioner.

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.

Formulation

Supports a positive mood

Non-GMO

Vegan/vegetarian

Not manufactured with wheat, gluten, soy, milk, egg, fish, shellfish or tree nut ingredients.

Natural color variation may occur in this product.

FDA Statement of Identity

A Dietary Supplement

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

See for yourself

5-HTP (5-Hydroxytryptophan) 200 mg by Protocol For Life Balance label

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

5-HTP (5-Hydroxytryptophan) 200 mg 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 5-HTP (5-Hydroxytryptophan) 200 mg by Protocol For Life Balance

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

Serving size1 Veg Capsule(s) Dosage formCapsule Servings per container60 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.

Vitamin B6

Interacts with
210 drugs
2 mg per serving Form: Pyridoxine Hydrochloride

Vitamin B6 (pyridoxine) is an essential water-soluble vitamin that your body needs for metabolism, brain function, and making red blood cells. It is b...

Vitamin B6 monograph & interactions

Glycine

Interacts with
1 drug
100 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...

Glycine monograph & interactions

5-HTP

Interacts with
398 drugs
200 mg per serving Form: Griffonia simplicifolia Seed Extract

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...

5-HTP monograph & interactions

Niacin

Interacts with
727 drugs
20 mg per serving Form: Vitamin B3

Niacin (vitamin B3) is an essential nutrient your body needs for energy and metabolism, and deficiency is uncommon in most developed countries. Prescr...

Niacin monograph & interactions

Taurine

Interacts with
173 drugs
100 mg per serving

Taurine is an amino acid your body makes naturally and that you also get from animal foods. It is widely used in energy drinks and sports supplements,...

Taurine monograph & interactions

Inositol

Interacts with
86 drugs
100 mg per serving

Inositol is a sugar alcohol made naturally in the body and found in many foods, and it is sold as a supplement (often myo-inositol) mainly for PCOS, m...

Inositol monograph & interactions

Other (inactive) ingredients: Hypromellose, Ascorbyl Palmitate, Silicon Dioxide. These complete the product’s ingredient list but are not active constituents.

Interaction report

5-HTP (5-Hydroxytryptophan) 200 mg by Protocol For Life Balance Drug Interactions

Want to check YOUR meds against 5-HTP (5-Hydroxytryptophan) 200 mg?

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
1,045Drugs
1,043 Moderate 2 Minor

Ingredients driving the most interactions

Niacin 727
5-HTP 398
Vitamin B6 210
Taurine 173
Inositol 86

Individual Drug Interactions

The ingredients in 5-HTP (5-Hydroxytryptophan) 200 mg interact with 1,045 drugs. Click any drug to see the details.

6 of the 6 ingredients in 5-HTP (5-Hydroxytryptophan) 200 mg interact with drugs. Each result below shows which ingredient is responsible. Niacin 5-HTP Vitamin B6 Taurine Inositol Glycine

Each ingredient & the kinds of drugs it affects

For each ingredient in 5-HTP (5-Hydroxytryptophan) 200 mg 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.

Niacin15 drug types · 727 drugs

Alcohol (Ethanol)

Concomitant use of alcohol and niacin might increase the risk of flushing and hepatotoxicity.
Alcohol can exacerbate the flushing and pruritus associated with niacin. Large doses of niacin might also exacerbate liver dysfunction associated with chronic alcohol use. A case report describes delirium and lactic acidosis in a patient taking niacin 3 grams daily who ingested 1 liter of wine. Advise patients to avoid large amounts of alcohol while taking niacin.

Likelihood Probable Evidence D
Allopurinol (Zyloprim)

Theoretically, niacin might antagonize the therapeutic effects of uricosurics such as allopurinol.
Large doses of niacin can reduce urinary excretion of uric acid, potentially resulting in hyperuricemia. Doses of uricosurics such as allopurinol might need to be increased to maintain control of gout in patients who start taking niacin. People who have frequent attacks of gout despite uricosuric therapy should avoid niacin.

Likelihood Probable Evidence C
Anticoagulant/Antiplatelet Drugs

Theoretically, niacin may have additive effects when used with anticoagulant or antiplatelet drugs.
Several cases of clotting factor synthesis deficiency and coagulopathy have been reported in patients taking sustained-release niacin. Also, thrombocytopenia has been reported in patients treated with niacin or niacin plus lovastatin.

Likelihood Possible Evidence D
Antidiabetes Drugs

Niacin can increase blood glucose levels and may diminish the effects of antidiabetes drugs.
Niacin impairs glucose tolerance in a dose-dependent manner, probably by causing or aggravating insulin resistance and increasing hepatic production of glucose. In diabetes patients, niacin 4.5 grams daily for 5 weeks can increase plasma glucose by an average of 16% and glycated hemoglobin (HbA1c) by 21%. However, lower doses of 1.5 grams daily or less appear to have minimal effects on blood glucose. In some patients, glucose levels increase when niacin is started, but then return to baseline when a stable dose is reached. Up to 35% of patients with diabetes may need adjustments in hypoglycemic therapy when niacin is added.

Likelihood Probable Evidence B
Antihypertensive Drugs

Theoretically, niacin may increase the risk of hypotension when used with antihypertensive drugs.
The vasodilating effects of niacin can cause hypotension. Furthermore, some clinical evidence suggests that a one-hour infusion of niacin can reduce systolic, diastolic, and mean blood pressure in hypertensive patients. This effect is not observed in normotensive patients.

Likelihood Possible Evidence B
Bile Acid Sequestrants

Bile acid sequestrants can bind niacin and decrease absorption. Separate administration by 4-6 hours to avoid an interaction.
In vitro studies show that colestipol (Colestid) binds about 98% of available niacin and cholestyramine (Questran) binds 10% to 30%.

Likelihood Possible Evidence D
Gemfibrozil (Lopid)

Theoretically, concomitant use of niacin and gemfibrozil might increase the risk of myopathy in some patients.
A case of myopathy from concomitant use of niacin and gemfibrozil has been reported. Niacin alone has also been associated with cases of myopathy. Using gemfibrozil with niacin might further increase the risk of developing myopathy.

Likelihood Possible Evidence D
Hepatotoxic Drugs

Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Niacin has been associated with cases of liver toxicity, especially when used in pharmacologic doses. Sustained-release niacin preparations appear to be associated with a higher risk of hepatotoxicity than immediate-release niacin.

Likelihood Possible Evidence D
Hmg-Coa Reductase Inhibitors ("Statins")

Theoretically, concomitant use of niacin and statins might increase the risk of myopathy and rhabdomyolysis in some patients.
Some case reports have raised concerns that niacin might increase the risk of myopathy and rhabdomyolysis when combined with statins. However, a significantly increased risk of myopathy has not been demonstrated in clinical trials, including those using an FDA-approved combination of lovastatin and niacin (Advicor).

Likelihood Possible Evidence D
Probenecid (Benemid)

Theoretically, niacin might antagonize the therapeutic effects of uricosurics such as probenecid.
Large doses of niacin reduce urinary excretion of uric acid, potentially causing hyperuricemia. Doses of uricosurics such as probenecid might need to be increased to maintain control of gout in patients who start taking niacin. People who have frequent attacks of gout despite uricosuric therapy should avoid niacin.

Likelihood Probable Evidence C
Sulfinpyrazone (Anturane)

Theoretically, niacin might antagonize the therapeutic effects of uricosurics such as sulfinpyrazone.
Large doses of niacin reduce urinary excretion of uric acid, potentially causing hyperuricemia. Doses of uricosurics such as sulfinpyrazone might need to be increased to maintain control of gout in patients who start taking niacin. People who have frequent attacks of gout despite uricosuric therapy should avoid niacin.

Likelihood Probable Evidence C
Thyroid Hormone

Theoretically, niacin might antagonize the therapeutic effects of thyroid hormones.
Clinical research and case reports suggests that taking niacin can reduce serum levels of thyroxine-binding globulin by up to 25% and moderately reduce levels of thyroxine (T4). Patients taking thyroid hormone for hypothyroidism might need dose adjustments when using niacin.

Likelihood Probable Evidence D
Transdermal Nicotine (Nicoderm)

Theoretically, concomitant use of niacin and transdermal nicotine might increase the risk of flushing and dizziness.
Niacin and nicotine can both cause flushing and dizziness.

Likelihood Possible Evidence D
Warfarin (Coumadin)

There is limited evidence that niacin may increase the anticoagulant effects of warfarin.
In a case report, a patient on warfarin developed an elevated international normalized ratio (INR) of 3.9 after taking niacin for two weeks. The patient's INR was previously stable, ranging between 2 and 3 in recent months, and no other medication changes were identified. The elevated INR returned to therapeutic range within 4 days following the discontinuation of niacin.

Likelihood Possible Evidence D
Aspirin

Large doses of aspirin might alter the clearance of niacin.
Aspirin is often used with niacin to reduce niacin-induced flushing. Doses of 80-975 mg aspirin have been used, but 325 mg appears to be optimal. Aspirin also seems to reduce the clearance of niacin by competing for glycine conjugation. Taking aspirin 1 gram seems to reduce niacin clearance by 45%. This is probably a dose-related effect and not clinically significant with the more common aspirin dose of 325 mg.

Likelihood Likely Evidence B
Niacin full monograph & interactions

5-HTP3 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
5-HTP full monograph & interactions

Vitamin B65 drug types · 210 drugs

Amiodarone (Cordarone)

Theoretically, vitamin B6 might increase the photosensitivity caused by amiodarone.
Despite initial case reports suggesting that pyridoxine may have a protective effect against amiodarone-induced photosensitivity, preliminary clinical research suggests that pyridoxine may actually exacerbate this adverse effect.

Likelihood Possible Evidence B
Antihypertensive Drugs

Theoretically, vitamin B6 may have additive effects when used with antihypertensive drugs.
Research in hypertensive rats shows that vitamin B6 can decrease systolic blood pressure. Similarly, clinical research in patients with hypertension shows that taking high doses of vitamin B6 may reduce systolic and diastolic blood pressure, possibly by reducing plasma levels of epinephrine and norepinephrine.

Likelihood Possible Evidence B
Phenobarbital (Luminal)

High doses of vitamin B6 may reduce the levels and clinical effects of phenobarbital.
Preliminary clinical evidence suggests that vitamin B6 200 mg daily can reduce plasma levels of phenobarbital, possibly by increasing metabolism. It is not known whether lower doses have any effect. Advise people taking phenobarbital to avoid high doses of vitamin B6.

Likelihood Possible Evidence D
Phenytoin (Dilantin)

High doses of vitamin B6 may reduce the levels and clinical effects of phenytoin.
Preliminary clinical evidence suggests that vitamin B6 200 mg daily can reduce plasma levels of phenytoin, possibly by increasing metabolism. It is not known whether lower doses have any effect. Advise people taking phenytoin to avoid high doses of vitamin B6.

Likelihood Possible Evidence D
Levodopa

Vitamin B6 may increase the metabolism of levodopa when taken alone, but not when taken in conjunction with carbidopa.
Vitamin B6 (pyridoxine) enhances the metabolism of levodopa, reducing its clinical effects. However, this interaction does not occur when carbidopa is used concurrently with levodopa (Sinemet). Therefore, it is not likely to be a problem in most people.

Likelihood Unlikely Evidence D
Vitamin B6 full monograph & interactions

Taurine2 drug types · 173 drugs

Antihypertensive Drugs

Theoretically, taurine might increase the risk of hypotension when taken with antihypertensive drugs.
Some clinical evidence suggests that taurine can reduce both systolic and diastolic blood pressure.

Likelihood Probable Evidence D
Lithium

Theoretically, taurine might reduce excretion and increase plasma levels of lithium.
Taurine is thought to have diuretic properties, which might reduce the excretion of lithium.

Likelihood Probable Evidence D
Taurine full monograph & interactions

Inositol1 drug type · 86 drugs

Antidiabetes Drugs

Theoretically, taking inositol with antidiabetes drugs might increase the risk of hypoglycemia.
Clinical research shows that inositol lowers blood glucose levels and glycated hemoglobin (HbA1c) levels in patients with diabetes.

Likelihood Possible Evidence A
Inositol full monograph & interactions

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
Glycine full monograph & interactions
The maker

Brand information

Manufacturer and brand details for 5-HTP (5-Hydroxytryptophan) 200 mg, from the product label.

Protocol For Life Balance

See all Protocol For Life Balance products
Name
Protocol For Life Balance
Street Address
395 S. Glen Ellyn Rd.
City
Bloomingdale
State
IL
ZipCode
60108
Web Address
www.protocolforlife.com
Pharmacist Counseling Corner

5-HTP (5-Hydroxytryptophan) 200 mg by Protocol For Life Balance: Common Questions

Does 5-HTP (5-Hydroxytryptophan) 200 mg by Protocol For Life Balance interact with any medications?
Yes. Based on its ingredients, 5-HTP (5-Hydroxytryptophan) 200 mg has a known interaction with 1,045 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
5-HTP (5-Hydroxytryptophan) 200 mg 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.
Can I take this while pregnant?
Two of the six ingredients—vitamin B6 and niacin—are rated likely safe in pregnancy at normal doses. However, 5-HTP and glycine don't have enough safety data in pregnancy and should be avoided unless your doctor approves. Inositol is possibly safe but should be used only under medical supervision. Because this is a combination product with mixed safety ratings, talk with your doctor or pharmacist before starting it.
What is 5-HTP and why is it in this product?
5-HTP is an amino acid your body makes from an amino acid called tryptophan. It's a step in the process of making serotonin, a brain chemical tied to mood and sleep. The supplement form is used to try to boost serotonin levels, though the evidence shows it's only possibly effective for depression and lacks strong evidence for most other uses.
Will this product make me drowsy?
Drowsiness and fatigue are common side effects of 5-HTP, especially when you first start taking it. They appear to be dose-dependent, meaning higher doses are more likely to cause them. If you're already taking sedating medications like antihistamines or sleep aids, adding this product could compound the drowsiness.
What's the most serious interaction I should know about?
Combining this product with serotonergic medications—mainly antidepressants like SSRIs, SNRIs, and certain others—carries a major risk of serotonin syndrome, a serious condition where too much serotonin builds up in your system. Check with your pharmacist right away if you take any antidepressant or mood-stabilizing medication.
Can I take this if I have diabetes or take blood pressure medication?
Both niacin in this product and inositol can affect blood sugar and blood pressure. Niacin can raise blood glucose and work against diabetes medications, while both niacin and taurine may add to the effects of blood-pressure drugs, raising the risk of dangerously low blood pressure. Talk with your doctor before starting.
Are there any fillers or other inactive ingredients I should know about?
Yes, the capsule contains hypromellose (a capsule material), ascorbyl palmitate (a form of vitamin C used as a preservative), and silicon dioxide (an anti-caking agent). If you have allergies to any of these, let your pharmacist know.

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

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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.

5-HTP (5-Hydroxytryptophan) 200 mg label
Go deeper

The Full Monographs Behind 5-HTP (5-Hydroxytryptophan) 200 mg’s Ingredients

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

Herb & supplement monograph

Vitamin B6

Interacts with 210 drugs

Vitamin B6 (pyridoxine) is an essential water-soluble vitamin that your body needs for metabolism, brain function, and making red blood cells. It is best known for helping with pregnancy-rel...

Read the full Vitamin B6 monograph → 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

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

Niacin

Interacts with 727 drugs

Niacin (vitamin B3) is an essential nutrient your body needs for energy and metabolism, and deficiency is uncommon in most developed countries. Prescription-strength niacin has been used to...

Read the full Niacin monograph → Herb & supplement monograph

Taurine

Interacts with 173 drugs

Taurine is an amino acid your body makes naturally and that you also get from animal foods. It is widely used in energy drinks and sports supplements, and short-term use appears generally sa...

Read the full Taurine monograph → Herb & supplement monograph

Inositol

Interacts with 86 drugs

Inositol is a sugar alcohol made naturally in the body and found in many foods, and it is sold as a supplement (often myo-inositol) mainly for PCOS, mood, and metabolic concerns. The stronge...

Read the full Inositol monograph →
Sources

Sources & How We Checked

5-HTP (5-Hydroxytryptophan) 200 mg'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 170 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.

Vitamin B6 32 references
  1. Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
  2. Yates AA, Schlicker SA, Suitor CW. Dietary reference intakes: The new basis for recommendations for calcium and related nutrients, B vitamins, and choline. J Am Diet Assoc 1998;98:699-706. PubMed
  3. Geerling BJ, Dagnelie PC, Badart-Smook A, et al. Diet as a risk factor for the development of ulcerative colitis. Am J Gastroenterol 2000;95:1008-13. PubMed
  4. South M. Neonatal seizures after pyridoxine use -- reply. Lancet 1999;354:2083. PubMed
  5. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (2000). Washington, DC: National Academy Press, 2000. Available at: http://b
  6. Baxter P, Aicardi J. Neonatal seizures after pyridoxine use. Lancet 1999;354:2082-3. PubMed
  7. Bendich A, Cohen M. Vitamin B6 safety issues. Ann N Y Acad Sci 1990;585:321-30.
  8. Schaumburg H, Kaplan J, Windebank A. Sensory neuropathy from pyridoxine abuse. A new megavitamin syndrome. N Engl J Med 1983;309:445-8. PubMed
  9. Gordon N. Pyridoxine dependency: an update. Dev Med Child Neurol 1997;39:63-5. PubMed
  10. Lewis PJ. Pain in the hand and wrist. Pyridoxine supplements may help patients with carpal tunnel syndrome. BMJ 1995;310:1534. PubMed
  11. Kaufman G. Pyridoxine against amiodarone-induced photosensitivity (letter). Lancet 1984;1:51-2. PubMed
  12. Mulrow JP, Mulrow CD, McKenna WJ. Pyridoxine and amiodarone-induced photosensitivity. Ann Intern Med 1985;103:68-9. PubMed
  13. Kawada A, Kashima A, Shiraishi H, et al. Pyridoxine-induced photosensitivity and hypophosphatasia. Dermatology 2000;201:356-60.. PubMed
  14. Vasile A, Goldberg R, Kornberg B. Pyridoxine toxicity: report of a case. J Am Osteopath Assoc 1984;83:790-1. DOI
  15. Hansson O, Sillanpaa M. Pyridoxine and serum concentration of phenytoin and phenobarbitone. Lancet 1976;1:256. DOI
  16. Jansen T, Romiti R, Kreuter A, Altmeyer P. Rosacea fulminans triggered by high-dose vitamins B6 and B12. J Eur Acad Dermatol Venereol 2001;15:484-5..
  17. Chittumma P, Kaewkiattikun K, Wiriyasiriwach B. Comparison of the effectiveness of ginger and vitamin B6 for treatment of nausea and vomiting in early pregnancy: a randomized double-blind controlled trial. J Med Assoc Thai 2007;90:15-20.
  18. Hatzitolios, A., Iliadis, F., Katsiki, N., and Baltatzi, M. Is the anti-hypertensive effect of dietary supplements via aldehydes reduction evidence based? A systematic review. Clin Exp.Hypertens. 2008;30(7):628-639. PubMed
  19. Vasdev, S., Ford, C. A., Parai, S., Longerich, L., and Gadag, V. Dietary vitamin B6 supplementation attenuates hypertension in spontaneously hypertensive rats. Mol.Cell Biochem. 1999;200(1-2):155-162.
  20. de, Vogel S., Dindore, V., van, Engeland M., Goldbohm, R. A., van den Brandt, P. A., and Weijenberg, M. P. Dietary folate, methionine, riboflavin, and vitamin B-6 and risk of sporadic colorectal cancer. J Nutr 2008;138(12):2372-2378. PubMed
  21. Hagen, I., Nesheim, B. I., and Tuntland, T. No effect of vitamin B-6 against premenstrual tension. A controlled clinical study. Acta Obstet.Gynecol.Scand. 1985;64(8):667-670. PubMed
  22. Aybak, M., Sermet, A., Ayyildiz, M. O., and Karakilcik, A. Z. Effect of oral pyridoxine hydrochloride supplementation on arterial blood pressure in patients with essential hypertension. Arzneimittelforschung. 1995;45(12):1271-1273.
  23. Lal, K. J., Dakshinamurti, K., and Thliveris, J. The effect of vitamin B6 on the systolic blood pressure of rats in various animal models of hypertension. J Hypertens. 1996;14(3):355-363. PubMed
  24. Lauritzen CH, Reuter HD, Repges R, Bohnert K, and Schmidt U. Treatment of premenstrual tension syndrome with Vitex agnus castus. Controlled, double-blind study versus pyridoxine. Phytomed 1997;4(3):183-189. PubMed
  25. Fonseca VA, Lavery LA, Thethi TK, et al. Metanx in type 2 diabetes with peripheral neuropathy: A randomized trial. Am J Med 2013;126(2):141-9. PubMed
  26. Hankey GJ, Eikelboom JW, Yi Q, et al. Treatment with B vitamins and incidence of cancer in patients with previous stroke or transient ischemic attack: Results of a randomized placebo-controlled trial. Stroke 2012;43(6):1572-7. PubMed
  27. Hoyer-Kuhn H, Kohbrok S, Volland R, Franklin J, Hero B, Beck BB, Hoppe B. Vitamin B6 in primary hyperoxaluria I: first prospective trial after 40 years of practice. Clin J Am Soc Nephrol. 2014 Mar;9(3):468-77. PubMed
  28. Mahmoud A, Tabassum S, Al Enazi S, et al. Amelioration of levetiracetam-induced behavioral side effects by pyridoxine. A randomized double blind controlled study. Pediatr Neurol 2021;119:15-21. PubMed
  29. Gupta M, Gallante B, Bamberger JN, et al. Prospective randomized evaluation of idiopathic hyperoxaluria treatments. J Endourol 2021;35(12):1844-1851. PubMed
  30. Li H, Chen M, Liang S, et al. Excessive vitamin B6 during treatment is related to poor prognosis of patients with nasopharyngeal carcinoma: A U-shaped distribution suggests low dose supplement. Clin Nutr 2021;40(4):2293-2300. PubMed
  31. Tanigawa J, Nabatame S, Tominaga K, et al. High-dose pyridoxine treatment for inherited glycosylphosphatidylinositol deficiency. Brain Dev 2021;43(6):680-687. PubMed
  32. Committee on Practice Bulletins-Obstetrics. ACOG Practice Bulletin No. 189: Nausea And Vomiting Of Pregnancy. Obstet Gynecol. 2018;131(1):e15-e30. PubMed

See these in context on the Vitamin B6 monograph →

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 →

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 →

Niacin 66 references
  1. Garg R, Malinow MR, Pettinger M, et al. Niacin treatment increases plasma homocysteine levels. Am Heart J 1999;138:1082-7.
  2. Anon. Inositol hexaniacinate. Altern Med Rev 1998;3:222-3.
  3. Knodel LC, Talbert RL. Adverse effects of hypolipidaemic drugs. Med Toxicol 1987;2:10-32. PubMed
  4. Guyton JR, Blazing MA, Hagar J, et al. Extended-release niacin vs gemfibrozil for the treatment of low levels of high-density lipoprotein cholesterol. Niaspan-Gemfibrozil Study Group. Arch Intern Med 2000;160:1177-84. PubMed
  5. Gibbons LW, Gonzalez V, Gordon N, Grundy S. The prevalence of side effects with regular and sustained-release nicotinic acid. Am J Med 1995;99:378-85. PubMed
  6. Whelan AM, Price SO, Fowler SF, Hainer BL. The effect of aspirin on niacin-induced cutaneous reactions. J Fam Pract 1992;34:165-8.
  7. Jungnickel PW, Maloley PA, Vander Tuin EL, et al. Effect of two aspirin pretreatment regimens on niacin-induced cutaneous reactions. J Gen Intern Med 1997;12:591-6. PubMed
  8. Capuzzi DM, Guyton JR, Morgan JM, et al. Efficacy and safety of an extended-release niacin (Niaspan): a long-term study. Am J Cardiol 1998;82:74-81;disc. 85U-6U. PubMed
  9. Gray DR, Morgan T, Chretien SD, Kashyap ML. Efficacy and safety of controlled-release niacin in dyslipoproteinemic veterans. Ann Intern Med 1994;121:252-8. PubMed
  10. McKenney JM, Proctor JD, Harris S, Chinchili VM. A comparison of the efficacy and toxic effects of sustained- vs immediate-release niacin in hypercholesterolemic patients. JAMA 1994;271:672-7. DOI
  11. Knopp RH, Alagona P, Davidson M, et al. Equivalent efficacy of a time-release form of niacin (Niaspan) given once-a-night versus plain niacin in the management of hyperlipidemia. Metabolism 1998;47:1097-104. PubMed
  12. Knopp RH. Clinical profiles of plain versus sustained-release niacin (Niaspan) and the physiologic rationale for nighttime dosing. Am J Cardiol 1998;82:24U-28U;discussion 39U-41U. PubMed
  13. Garg A, Grundy SM. Nicotinic acid as therapy for dyslipidemia in non-insulin-dependent diabetes mellitus. JAMA 1990;264:723-6. DOI
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  15. American Society of Health-System Pharmacists. ASHP Therapeutic Position Statement on the safe use of niacin in the management of dyslipidemias. Am J Health Syst Pharm 1997;54:2815-9. DOI
  16. Vega GL, Grundy SM. Lipoprotein responses to treatment with lovastatin, gemfibrozil, and nicotinic acid in normolipidemic patients with hypoalphalipoproteinemia. Arch Intern Med 1994;154:73-82. DOI
  17. Guyton JR, Goldberg AC, Kreisberg RA, et al. Effectiveness of once-nightly dosing of extended-release niacin alone and in combination for hypercholesterolemia. Am J Cardiol 1998;82:737-43.
  18. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (2000). Washington, DC: National Academy Press, 2000. Available at: http://b
  19. Brown BG, Zhao XQ, Chait A, et al. Simvastatin and niacin, antioxidant vitamins, or the combination for the prevention of coronary disease. N Engl J Med 2001;345:1583-93. DOI
  20. Bays HE, Dujovne CA. Drug interactions of lipid-altering drugs. Drug Saf 1998;19:355-71. PubMed
  21. Rader JI, Calvert RJ, Hathcock JN. Hepatic toxicity of unmodified and time-release preparations of niacin. Am J Med 1992;92:77-81. PubMed
  22. Kahn SE, Beard JC, Schwartz MW, et al. Increased B-cell secretory capacity as mechanism for islet adaptation to nicotinic acid-induced insulin resistance. Diabetes 1989;38:562-8.
  23. Schwartz ML. Severe reversible hyperglycemia as a consequence of niacin therapy. Arch Int Med 1993;153:2050-2. DOI
  24. Raising HDL and Niacin Use. Pharmacist's Letter/Prescriber's Letter 2004;20(5):200504.
  25. McKenney J. New perspectives on the use of niacin in the treatment of lipid disorders. Arch Intern Med 2004;164:697-705. PubMed
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  27. Ito MK. Advances in the understanding and management of dyslipidemia: using niacin-based therapies. Am J Health-Syst Pharm 2003;60(suppl 2):s15-21. PubMed
  28. Schwab RA, Bachhuber BH. Delirium and lactic acidosis caused by ethanol and niacin coingestion. Am J Emerg Med 1991;9:363-5. PubMed
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  32. Dearing BD, Lavie CJ, Lohmann TP, Genton E. Niacin-induced clotting factor synthesis deficiency with coagulopathy. Arch Intern Med. 1992;152(4):861-3. DOI
  33. O'Brien T, Silverberg JD, Nguyen TT. Nicotinic acid-induced toxicity associated with cytopenia and decreased levels of thyroxine-binding globulin. Mayo Clin Proc. 1992;67(5):465-8. PubMed
  34. Gadegbeku CA, Dhandayuthapani A, Shrayyef MZ, Egan BM. Hemodynamic effects of nicotinic acid infusion in normotensive and hypertensive subjects. Am J Hypertens. 2003;16(1):67-71. PubMed
  35. Garnett WR. Interactions with hydroxymethylglutaryl-coenzyme A reductase inhibitors. Am J Health Syst Pharm. 1995;52(15):1639-45. PubMed
  36. Litin SC, Anderson CF. Nicotinic acid-associated myopathy: a report of three cases. Am J Med. 1989;86(4):481-3. PubMed
  37. Dunn RT, Ford MA, Rindone JP, Kwiecinski FA. Low-Dose Aspirin and Ibuprofen Reduce the Cutaneous Reactions Following Niacin Administration. Am J Ther. 1995;2(7):478-480. PubMed
  38. Cashin-Hemphill L, Spencer CA, Nicoloff JT, et al. Alterations in serum thyroid hormonal indices with colestipol-niacin therapy. Ann Intern Med. 1987;107(3):324-9. PubMed
  39. Drinka PJ. Alterations in thyroid and hepatic function tests associated with preparations of sustained-release niacin. Mayo Clin Proc. 1992;67(12):1206. PubMed
  40. Shakir KM, Kroll S, Aprill BS, Drake AJ 3rd, Eisold JF. Nicotinic acid decreases serum thyroid hormone levels while maintaining a euthyroid state. Mayo Clin Proc. 1995;70(6):556-8. PubMed
  41. Etchason JA, Miller TD, Squires RW, et al. Niacin-induced hepatitis: a potential side effect with low-dose time-release niacin. Mayo Clin Proc. 1991;66(1):23-8. PubMed
  42. Henkin Y, Johnson KC, Segrest JP. Rechallenge with crystalline niacin after drug-induced hepatitis from sustained-release niacin. JAMA. 1990;264(2):241-3. DOI
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  44. Brown BG, Bardsley J, Poulin D, et al. Moderate dose, three-drug therapy with niacin, lovastatin, and colestipol to reduce low-density lipoprotein cholesterol <100 mg/dl in patients with hyperlipidemia and coronary artery disease. Am J Cardiol. 1997;80(2)
  45. Goldberg A, Alagona P Jr, Capuzzi DM, et al. Multiple-dose efficacy and safety of an extended-release form of niacin in the management of hyperlipidemia. Am J Cardiol. 2000;85(9):1100-5. PubMed
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  47. Morgan JM, Capuzzi DM, Guyton JR, et al. Treatment Effect of Niaspan, a Controlled-release Niacin, in Patients With Hypercholesterolemia: A Placebo-controlled Trial. J Cardiovasc Pharmacol Ther. 1996;1(3):195-202. PubMed
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  51. Gharavi AG, Diamond JA, Smith DA, Phillips RA. Niacin-induced myopathy. Am J Cardiol. 1994;74(8):841-2. PubMed
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  53. Fraunfelder FW, Fraunfelder FT, Illingworth DR. Adverse ocular effects associated with niacin therapy. Br J Ophthalmol 1995;79:54-56. PubMed
  54. Ali EH, McJunkin B, Jubelirer S, Hood W. Niacin induced coagulopathy as a manifestation of occult liver injury. W V Med J. 2013 Jan-Feb;109(1):12-4
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  58. Guyton JR, Fazio S, Adewale AJ, Jensen E, Tomassini JE, Shah A, Tershakovec AM. Effect of extended-release niacin on new-onset diabetes among hyperlipidemic patients treated with ezetimibe/simvastatin in a randomized controlled trial. Diabetes Care. 2012 PubMed
  59. Loebl T, Raskin S. A novel case report: acute manic psychotic episode after treatment with niacin. J Neuropsychiatry Clin Neurosci. 2013 Fall;25(4):E14. PubMed
  60. Teo KK, Goldstein LB, Chaitman BR, Grant S, Weintraub WS, Anderson DC, Sila CA, Cruz-Flores S, Padley RJ, Kostuk WJ, Boden WE; AIM-HIGH Investigators. Extended-release niacin therapy and risk of ischemic stroke in patients with cardiovascular disease: the
  61. Goldie C, Taylor AJ, Nguyen P, McCoy C, Zhao XQ, Preiss D. Niacin therapy and the risk of new-onset diabetes: a meta-analysis of randomized controlled trials. Heart. 2016 Feb;102(3):198-203.
  62. Schandelmaier S, Briel M, Saccilotto R, Olu KK, Arpagaus A, Hemkens LG, Nordmann AJ. Niacin for primary and secondary prevention of cardiovascular events. Cochrane Database Syst Rev. 2017 Jun 14;6:CD009744. PubMed
  63. Jenkins DJA, Spence JD, Giovannucci EL, et al. Supplemental vitamins and minerals for CVD prevention and treatment. J Am Coll Cardiol 2018;71(22):2570-84. PubMed
  64. Song S, Lee CJ, Oh J, Park S, Kang SM, Lee SH. Effect of Niacin on Carotid Atherosclerosis in Patients at Low-Density Lipoprotein-Cholesterol Goal but High Lipoprotein (a) Level: a 2-Year Follow-Up Study. J Lipid Atheroscler. 2019;8(1):58-66. PubMed
  65. Kimura H, Umemori Y, Yuki D. Anaphylactic shock-like symptoms due to niacin overdose: A case report. J Dermatol 2022;49(8):e287-e288. PubMed
  66. Nawaz N, Mistretta T, Karime C, Lewis J, Wolf E. Cholestatic Drug-Induced Liver Injury in a Patient Taking High-Dose Niacin for Hyperlipidemia. J Investig Med High Impact Case Rep 2024;12:23247096231224349. PubMed

See these in context on the Niacin monograph →

Taurine 21 references
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  2. Machado-Vieira R, Viale CI, Kapczinski F. Mania associated with an energy drink: the possible role of caffeine, taurine, and inositol. Can J Psychiatry 2001;46:454-5. PubMed
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  5. Iyadurai, S. J. and Chung, S. S. New-onset seizures in adults: possible association with consumption of popular energy drinks. Epilepsy Behav 2007;10(3):504-508. PubMed
  6. Berger, A. J. and Alford, K. Cardiac arrest in a young man following excess consumption of caffeinated "energy drinks". Med J Aust. 1-5-2009;190(1):41-43. PubMed
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  8. Morchon, Simon D. and Perez Castrillon, J. L. [Hypoglycemia by intake of taurine]. Rev.Clin Esp. 2010;210(1):49.
  9. Livshits, Z., Hoffman, R. S., Hymes, K. B., and Nelson, L. S. If vitamins could kill: massive hemolysis following naturopathic vitamin infusion. J Med Toxicol. 2011;7(3):224-226. PubMed
  10. Schoffl, I., Kothmann, J. F., Schoffl, V., Rupprecht, H. D., and Rupprecht, T. "Vodka energy": too much for the adolescent nephron? Pediatrics 2011;128(1):e227-e231. PubMed
  11. Calabro, R. S., Italiano, D., Gervasi, G., and Bramanti, P. Single tonic-clonic seizure after energy drink abuse. Epilepsy Behav 2012;23(3):384-385. PubMed
  12. Fujita, T., Ando, K., Noda, H., Ito, Y., and Sato, Y. Effects of increased adrenomedullary activity and taurine in young patients with borderline hypertension. Circulation 1987;75(3):525-532. PubMed
  13. Darling, P. B., Lepage, G., Leroy, C., Masson, P., and Roy, C. C. Effect of taurine supplements on fat absorption in cystic fibrosis. Pediatr Res 1985;19(6):578-582. PubMed
  14. Fukuyama, Y. and Ochiai, Y. Therapeutic trial by taurine for intractable childhood epilepsies. Brain Dev. 1982;4(1):63-69. PubMed
  15. Franconi, F., Bennardini, F., Mattana, A., Miceli, M., Ciuti, M., Mian, M., Gironi, A., Anichini, R., and Seghieri, G. Plasma and platelet taurine are reduced in subjects with insulin-dependent diabetes mellitus: effects of taurine supplementation. Am.J. DOI
  16. Stohs SJ, Miller M. A case study involving allergic reactions to sulfur-containing compounds including, sulfite, taurine, acesulfame potassium and sulfonamides. Food Chem Toxicol. 2014 Jan;63:240-3. PubMed
  17. Sun Q, Wang B, Li Y, Sun F, et al. Taurine supplementation lowers blood pressure and improves vascular function in prehypertension: randomized, double-blind, placebo-controlled study. Hypertension 2016 Mar;67(3):541-9. PubMed
  18. Jang ES, Hwang SH, Kim JW, Jeong SH. Effectiveness of 4-week oral taurine treatment for muscle cramps in patients with liver cirrhosis: a single-arm pilot study. Yonsei Med J 2021;62(1):21-8. PubMed
  19. Guan L, Miao P. The effects of taurine supplementation on obesity, blood pressure and lipid profile: A meta-analysis of randomized controlled trials. Eur J Pharmacol 2020;885:173533. PubMed
  20. Higgins JP, Liras GN, Liras IN, et al. Energy Drink Effects on Hemodynamics and Endothelial Function in Young Adults. Cardiology. 2021;146(2):258-262. PubMed
  21. Pallangyo P, Bhalia SV, Komba M, et al. Acute Myocardial Infarction Following the Consumption of Energy Drink in a 28-Year-Old Male: A Case Report. J Investig Med High Impact Case Rep. 2023 Jan-Dec;11:23247096231168811. PubMed

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Inositol 14 references
  1. Palatnik A, Frolov K, Fux M, Benjamin J. Double-blind, controlled, crossover trial of inositol versus fluvoxamine for the treatment of panic disorder. J Clin Psychopharmacol 2001;21:335-9.. PubMed
  2. Allan SJ, Kavanagh GM, Herd RM, Savin JA. The effect of inositol supplements on the psoriasis of patients taking lithium: a randomized, placebo-controlled trial. Br J Dermatol 2004;150:966-9. PubMed
  3. Machado-Vieira R, Viale CI, Kapczinski F. Mania associated with an energy drink: the possible role of caffeine, taurine, and inositol. Can J Psychiatry 2001;46:454-5. PubMed
  4. Kamenov Z, Kolarov G, Gateva A, Carlomagno G, Genazzani AD. Ovulation induction with myo-inositol alone and in combination with clomiphene citrate in polycystic ovarian syndrome patients with insulin resistance. Gynecol Endocrinol 2015;31(2):131-5. PubMed
  5. Matarrelli B, Vitacolonna E, D'Angelo M, et al. Effect of dietary myo-inositol supplementation in pregnancy on the incidence of maternal gestational diabetes mellitus and fetal outcomes: a randomized controlled trial. J Matern Fetal Neonatal Med 2013;26(1 PubMed
  6. Mukai T, Kishi T, Matsuda Y, Iwata N. A meta-analysis of inositol for depression and anxiety disorders. Hum Psychopharmacol 2014;29(1):55-63. PubMed
  7. Farren M, Daly N, McKeating A, Kinsley B, Turner MJ, Daly S. The Prevention of Gestational Diabetes Mellitus With Antenatal Oral Inositol Supplementation: A Randomized Controlled Trial. Diabetes Care. 2017;40(6):759-63. PubMed
  8. Zheng X, Liu Z, Zhang Y, et al. Relationship Between Myo-Inositol Supplementary and Gestational Diabetes Mellitus: A Meta-Analysis. Medicine (Baltimore). 2015;94(42):e1604. PubMed
  9. Crawford TJ, Crowther CA, Alsweiler J, Brown J. Antenatal dietary supplementation with myo-inositol in women during pregnancy for preventing gestational diabetes. Cochrane Database Syst Rev. 2015;(12):CD011507. PubMed
  10. Maurizi AR, Menduni M, Del Toro R, et al. A pilot study of D-chiro-inositol plus folic acid in overweight patients with type 1 diabetes. Acta Diabetol. 2017;54(4):361-65. PubMed
  11. Leppink EW, Redden SA, Grant JE. A double-blind, placebo-controlled study of inositol in trichotillomania. Int Clin Psychopharmacol. 2017;32(2):107-14. PubMed
  12. Lam S, Mandrekar SJ, Gesthalter Y. A Randomized Phase IIb Trial of myo-Inositol in Smokers with Bronchial Dysplasia. Cancer Prev Res (Phila). 2016;9(12):906-14.
  13. Wozniak J, Faraone SV, Chan J, et al. A randomized clinical trial of high eicosapentaenoic acid omega-3 fatty acids and inositol as monotherapy and in combination in the treatment of pediatric bipolar spectrum disorders: a pilot study. J Clin Psychiatry. PubMed
  14. Vitale SG, Corrado F, Caruso S, et al. Myo-inositol supplementation to prevent gestational diabetes in overweight non-obese women: bioelectrical impedance analysis, metabolic aspects, obstetric and neonatal outcomes - a randomized and open-label, placebo-

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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.

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