Interactions on record — worth a quick check against your medications. Check your meds →
Dietary supplement

5-HTP Plus Formula Ingredients & Drug Interactions

by Douglas Laboratories

5-HTP Plus Formula label
See full label image
Capsule Category: Other Combinations
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 9, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking 5-HTP Plus Formula 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 Plus Formula is a dietary supplement by Douglas Laboratories with 4 active ingredients. Its ingredients are commonly taken for low mood or depression, anxiety and stress, sleep problems.Based on those ingredients, 588 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are L-5-Hydroxytryptophan, Pyridoxal 5-Phosphate, L-Glutamine. 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 Plus Formula by Douglas Laboratories

Ask about any prescription or over-the-counter medication and we check it for interactions with 5-HTP Plus Formula by Douglas Laboratories — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of 5-HTP Plus Formula by Douglas Laboratories

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 12, 2026

What’s inside

Partial disclosure
Ingredient Transparency · database check
Partial

Most active ingredients list an amount, but at least one is hidden in a blend or missing.

Why this rating?
  • The label discloses an exact amount for 2 of its 4 active ingredients.
  • “Proprietary Blend” is a proprietary blend — the label gives one combined amount (50 mg) without saying how much of each component you get.

5-HTP Plus Formula contains four active ingredients. L-5-Hydroxytryptophan (5-HTP) is an amino acid precursor to serotonin, the brain chemical involved in mood regulation.

L-Glutamine supports muscle and gut function, particularly during stress or illness. L-Tyrosine is an amino acid that supports mental focus and the production of neurotransmitters.

Pyridoxal 5-Phosphate is the active form of vitamin B6, a cofactor for dozens of enzymes in your body. The capsule also contains inactive ingredients: microcrystalline cellulose, silica, and the capsule itself.

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

This product doesn't appear to be marketed for a specific use, so we graded its ingredients' overall clinical evidence instead.

Strong

Strong clinical evidence supports its ingredients for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredients' overall clinical evidence instead.
  • On file: Phenylketonuria (PKU) — rated "Effective" (Tyrosine) (Natural Medicines).
  • On file: Sickle cell disease — rated "Effective" (Glutamine) (Natural Medicines).
  • On file: Pyridoxine-dependent epilepsy — rated "Effective" (Vitamin B6) (Natural Medicines).
  • On file: Sideroblastic anemia — rated "Effective" (Vitamin B6) (Natural Medicines).
  • On file: Vitamin B6 deficiency — rated "Effective" (Vitamin B6) (Natural Medicines).

The evidence for this combination as a single product isn't on file with us. Individually, 5-HTP is possibly effective for depression.

L-Glutamine is effective for sickle cell disease and possibly effective for recovery from surgery or critical illness. L-Tyrosine is effective for phenylketonuria (PKU) and possibly effective for cognitive function and memory.

Vitamin B6 is effective for treating vitamin B6 deficiency and certain types of anemia, and possibly effective for pregnancy-related nausea. If you're considering this formula for a specific reason, talk with your pharmacist about whether the individual ingredients match your goal.

The evidence, ingredient by ingredient 5-htp Vitamin B6 Glutamine Tyrosine

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 4 of the 4 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 4 of 4.
  • General safety write-ups exist for 4 of 4.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

All four ingredients are generally well tolerated at typical doses. L-Glutamine can cause belching, bloating, constipation, nausea, diarrhea, and gastrointestinal pain; a small number of people with bipolar disorder have reported mania or hypomania.

L-Tyrosine may cause fatigue, headache, heartburn, and nausea. 5-HTP commonly causes nausea, diarrhea, headache, dizziness, drowsiness, and abdominal pain, though some of these effects may diminish with time; in rare cases, it has been linked to hallucinations, mania, and aggression.

Vitamin B6 is safe at doses under 100 mg daily, but high doses over long periods can damage nerves (sensory neuropathy). Regarding pregnancy: L-Glutamine is likely safe; 5-HTP safety data is insufficient—the facts advise against it in pregnancy; vitamin B6 is likely safe at recommended doses but possibly unsafe at high doses.

For breastfeeding: L-Glutamine safety data is insufficient; 5-HTP safety data is insufficient and the facts advise against it; vitamin B6 is likely safe. Talk with your doctor or midwife before using this product during pregnancy or while nursing.

Side effects, ingredient by ingredient 5-htp Vitamin B6 Glutamine Tyrosine

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?
  • 4 of the 4 matched ingredients can interact with medications — 5-htp, Glutamine, Vitamin B6, Tyrosine.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: seizure medications; Parkinson's medications.
  • For scale: 588 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 5-HTP Plus Formula, check your medications against these drug types: serotonergic drugs and antidepressants (Moderate risk of serotonin syndrome), CNS depressants like sleep aids (Moderate additive sedation), levodopa for Parkinson's (Moderate reduction in effectiveness), thyroid hormone medications (Moderate additive effects), antihypertensive drugs for high blood pressure (Moderate blood pressure lowering), seizure medications like phenytoin and phenobarbital (Moderate loss of effect), amiodarone for heart rhythm (Moderate photosensitivity risk), and carbidopa (Moderate serotonergic side effects). Use the medication search tool on this page to verify your exact prescriptions.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glancePartially disclosed formula with strong clinical evidence behind its ingredients' uses. Moderate medication interactions have been identified, and safety information is well characterized.

This formula is worth discussing with your pharmacist, especially if you take any psychiatric medications, seizure drugs, blood pressure medications, or thyroid replacement. The serotonin interactions with 5-HTP are the biggest concern.

If you're pregnant or nursing, check with your doctor first—the safety data for 5-HTP in particular is limited. Start low and go slow, and report any dizziness, mood changes, or worsening nausea.

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

Assessment coverage: 4 of 4 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Aug 23, 2020.

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 Plus Formula, straight from the product label.

Brand Douglas Laboratories
Barcode (UPC) 310539850732
Net contents 60 Vegetarian Capsule(s)
Market status On market
Date entered into DSLD Aug 23, 2020
DSLD ID 232007
Product type Other Combinations
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Women (not pregnant or lactating), Gluten 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 Plus Formula by Douglas Laboratories, 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 Vegetarian Capsule(s)
Maximum serving Sizes:
1 Vegetarian Capsule(s)
Servings per container
60
UPC/BARCODE
310539850732
IngredientAmount% DV
L-Glutamine0 NP--
L-Tyrosine0 NP--
L-5-Hydroxytryptophan75 mg--
Pyridoxal 5-Phosphate7.5 mg--
Proprietary Blend50 mg--

Other ingredients: Microcrystalline Cellulose, Capsule, Silica

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:As a dietary supplement, adults take 1 capsule daily or as directed by your health professional.

Precautions

Warning: Not to be taken by pregnant or lactating women. If you have any health condition or are taking any medication, particularly antidepressants or other psychiatric medications, consult your health professional before use.

Keep out of reach of children.

Use only if safety seal is intact.

Storage

Store in a cool, dry place.

Formulation

Gluten Free, Non-GMO

Brain serotonin precursor

FDA Disclaimer Statement

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

General Statements

Scan to learn about our manufacturing excellence Contents may not fill package in order to accommodate required labeling. Please rely on stated quantity.

FDA Statement of Identity

Dietary Supplement

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

See for yourself

5-HTP Plus Formula by Douglas Laboratories label

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

5-HTP Plus Formula 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 Plus Formula by Douglas Laboratories

These are the 4 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Vegetarian 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.

L-5-Hydroxytryptophan

Interacts with
398 drugs
75 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

Pyridoxal 5-Phosphate

Interacts with
210 drugs
7.5 mg per serving

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...

Pyridoxal 5-Phosphate monograph & interactions

Proprietary Blend

50 mg per serving

Other (inactive) ingredients: Microcrystalline Cellulose, Capsule, Silica. These complete the product’s ingredient list but are not active constituents.

Interaction report

5-HTP Plus Formula by Douglas Laboratories Drug Interactions

Want to check YOUR meds against 5-HTP Plus Formula?

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
588Drugs
588 Moderate

Ingredients driving the most interactions

L-5-Hydroxytryptophan 398
Pyridoxal 5-Phosphate 210
L-Glutamine 50
L-Tyrosine 21

Individual Drug Interactions

The ingredients in 5-HTP Plus Formula interact with 588 drugs. Click any drug to see the details.

4 of the 4 ingredients in 5-HTP Plus Formula interact with drugs. Each result below shows which ingredient is responsible. L-5-Hydroxytryptophan Pyridoxal 5-Phosphate L-Glutamine L-Tyrosine

Each ingredient & the kinds of drugs it affects

For each ingredient in 5-HTP Plus Formula 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.

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

Pyridoxal 5-Phosphate5 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
Pyridoxal 5-Phosphate full monograph & interactions

L-Glutamine1 drug type · 50 drugs

Anticonvulsants

Theoretically, glutamine might antagonize the effects of anticonvulsant medications.
Glutamine is metabolized to the excitatory neurotransmitter glutamate. Glutamate might have antagonistic effects with anticonvulsant drugs. However, this interaction has not yet been reported in humans.

Likelihood Possible Evidence D
L-Glutamine full monograph & interactions

L-Tyrosine2 drug types · 21 drugs

Levodopa

Theoretically, tyrosine might decrease the effectiveness of levodopa.
Tyrosine and levodopa compete for absorption in the proximal duodenum by the large neutral amino acid (LNAA) transport system. Advise patients to separate doses of tyrosine and levodopa by at least 2 hours.

Likelihood Probable Evidence D
Thyroid Hormone

Theoretically, tyrosine might have additive effects with thyroid hormone medications.
Tyrosine is a precursor to thyroxine and might increase levels of thyroid hormones.

Likelihood Probable Evidence D
L-Tyrosine full monograph & interactions
The maker

Brand information

Manufacturer and brand details for 5-HTP Plus Formula, from the product label.

Douglas Laboratories

See all Douglas Laboratories products
Name
Douglas Laboratories
Street Address
600 Boyce Road
City
Pittsburgh
State
PA
ZipCode
15205
Phone Number
1.800.245.4440
Web Address
www.douglaslabs.com
Pharmacist Counseling Corner

5-HTP Plus Formula by Douglas Laboratories: Common Questions

Does 5-HTP Plus Formula by Douglas Laboratories interact with any medications?
Yes. Based on its ingredients, 5-HTP Plus Formula has a known interaction with 588 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
5-HTP Plus Formula contains 4 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.
Will this help with depression?
5-HTP in this formula is possibly effective for depression, but we don't have effectiveness data for the combination as a whole. The evidence for 5-HTP alone is not strong. Talk to your doctor about whether it's right for you, especially if you're already on an antidepressant—the combination can raise serotonin too much.
Can I take this if I'm on an antidepressant?
No—not without checking with your pharmacist or doctor first. 5-HTP works by raising serotonin, just like antidepressants do. Combining them creates a Moderate risk of too much serotonin (serotonin syndrome), which can cause agitation, rapid heart rate, high blood pressure, and other serious effects. Your doctor may be able to adjust your medications safely if 5-HTP is important to you.
What's the most common side effect I might notice?
Nausea, diarrhea, and headache are the most common side effects from 5-HTP. Some people also report drowsiness or abdominal discomfort. These effects are often dose-related—starting low and increasing slowly, or taking the capsules with food, may help. A small number of trial participants experienced mood changes like anxiety or insomnia.
Is it safe during pregnancy or while breastfeeding?
L-Glutamine is likely safe in pregnancy, but 5-HTP and L-Tyrosine don't have enough safety data—the facts recommend avoiding 5-HTP during pregnancy and while nursing. Vitamin B6 is likely safe at normal recommended doses during pregnancy, but high doses are possibly unsafe. Talk with your doctor or midwife before starting; they can help you weigh the pros and cons for your situation.
What is L-Glutamine in this formula for?
L-Glutamine supports muscle recovery and gut health, especially during times of physical stress, illness, or surgery. It's effective for sickle cell disease and possibly effective for recovery after surgery or critical illness. In this formula it's combined with other amino acids and B6 to support overall neurological function.
Will this interact with my thyroid medication?
Yes—L-Tyrosine in this formula could have additive effects with thyroid hormone replacements, potentially raising your thyroid hormone levels more than intended. This is a Moderate interaction. Check with your pharmacist before starting, and if you do take it together, your doctor may want to monitor your thyroid levels or adjust your dose.

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 Plus Formula label
Go deeper

The Full Monographs Behind 5-HTP Plus Formula’s Ingredients

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

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

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

Glutamine

Interacts with 50 drugs

Glutamine is the most abundant amino acid in the body and is usually made in your muscles. A prescription form is FDA-approved to help reduce sickle cell disease complications, but for most...

Read the full Glutamine monograph → Herb & supplement monograph

Tyrosine

Interacts with 21 drugs

L-tyrosine is an amino acid your body uses to make brain chemicals like dopamine and norepinephrine. Some studies suggest it may help mental performance during short-term stress, sleep loss,...

Read the full Tyrosine monograph →
Sources

Sources & How We Checked

5-HTP Plus Formula'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 79 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.

Glutamine 11 references
  1. Miller AL. Therapeutic considerations of L-glutamine: a review of the literature. Altern Med Rev 1999;4:239-48..
  2. Bozzetti F, Biganzoli L, Gavazzi C, et al. Glutamine supplementation in cancer patients receiving chemotherapy: a double-blind randomized study. Nutrition 1997;13:748-51.. PubMed
  3. Mebane AH. L-Glutamine and mania. Am J Psychiatry 984;141:1302-3.
  4. Meldrum BS. Glutamate as a neurotransmitter in the brain: review of physiology and pathology. J Nutr 2000;130:1007S-15S.. PubMed
  5. Garlick PJ. Assessment of the safety of glutamine and other amino acids. J Nutr 2001;131:2556S-61S.. PubMed
  6. Chapman AG. Glutamate and epilepsy. J Nutr 2000;130:1043S-5S.. PubMed
  7. Ziegler TR. Glutamine supplementation in cancer patients receiving bone marrow transplantation and high dose chemotherapy. J Nutr 2001;131:2578S-84S.. PubMed
  8. Laviano A, Molfino A, Lacaria MT, Canelli A, De Leo S, Preziosa I, Rossi Fanelli F. Glutamine supplementation favors weight loss in nondieting obese female patients. A pilot study. Eur J Clin Nutr. 2014 Nov;68(11):1264-6. PubMed
  9. Endari (l-glutamine) [package insert]. Torrance, CA: Emmaus Medical,Inc; 2017.
  10. Niihara Y, Miller ST, Kanter J, et al. A Phase 3 Trial of l-Glutamine in Sickle Cell Disease. N Engl J Med 2018;379(3):226-35. doi: 10.1056/NEJMoa1715971.
  11. Ogden HB, Child RB, Fallowfield JL, et al. Gastrointestinal Tolerance of Low, Medium and High Dose Acute Oral l-Glutamine Supplementation in Healthy Adults: A Pilot Study. Nutrients. 2020;12(10):2953. PubMed

See these in context on the Glutamine monograph →

Tyrosine 4 references
  1. Meyer JS, Welch KM, Deshmukh VD, et al. Neurotransmitter precursor amino acids in the treatment of multi-infarct dementia and Alzheimer's disease. J Amer Geriat Soc 1977;25:289-98.
  2. DiPiro JT, Talbert RL, Yee GC, et al; eds. Pharmacotherapy: A pathophysiologic approach. 4th ed. Stamford, CT: Appleton & Lange, 1999.
  3. Wood DR, Reimherr FW, Wender PH. Amino acid precursors for the treatment of attention deficit disorder, residual type. Psychopharmacol Bull 1985;21:146-9.
  4. van Spronsen FJ, van Rijn M, Bekhof J. Phenylketonuria: tyrosine supplementation in phenylalanine-restricted diets. Am J Clin Nutr 2001;73:153-7. PubMed

See these in context on the Tyrosine 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.
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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.

© 2021 Therapeutic Research Center, LLC

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