5-Hydroxytryptophan • 100 mg

60 Enteric Coated Caplets ( SKU: 9288, NPN: 80038036 )


  • Naturally sourced from the seed of African plant Griffonia simplicifolia
  • Unlike L-tryptophan, 5-HTP readily crosses the blood-brain barrier increasing central nervous system synthesis of serotonin11
  • Enteric coated to reduce the likelihood of nausea  

Feature Summary

5-Hydroxytryptophan (5-HTP) is an amino acid that is the middle step between tryptophan and neurotransmitter serotonin. Scientific evidence indicates that low serotonin levels are linked to a number of common conditions, including depression, obesity, headache/migraine and fibromyalgia. 5-HTP boosts serotonin levels and may offer a benefit in conditions linked to low serotonin levels.1

5-HTP may help patients unresponsive to standard antidepressant drugs and some evidence suggests it may be comparable, if not superior, to conventional antidepressants, with fewer side effects.2 Taking 5-HTP can also aid pain syndromes such as migraine and fibromyalgia.3 It is thought both conditions reflect a serotonergic defect. Fibromyalgia suffers have experienced improved symptoms including pain severity, morning stiffness, and sleeplessness with 5-HTP supplementation.3,4,5 5-HTP is known to increase sleep quality, which is critical in those patients suffering from depression or fibromyalgia. In fact, 5-HTP is known to promote and maintain sleep in normal subjects, as well as those experiencing insomnia.6  

Research has indicated that 5-HTP may aid weight loss. Early animal studies indicated that genetically obese rats had decreased activity of the enzyme that converts tryptophan to 5-HTP and subsequently serotonin, allowing them to over eat.7 The same mechanism exists in genetically predisposed humans. By providing preformed 5-HTP, this genetic defect is bypassed and more serotonin is manufactured. Human clinical trials have corroborated that 5-HTP is able to reduce caloric intake, promote satiety and induce weight loss without conscious effort by subjects to lose weight.8,9,10  

Medicinal Ingredients

Each Caplet Contains:
L-5-Hydroxytryptophan (Griffonia simplicifolia) (seed) 100 mg

Non-Medicinal Ingredients

Dibasic calcium phosphate dihydrate, purified water, microcrystalline cellulose, enteric coating (purified water, ethylcellulose, medium chain triglycerides, oleic acid, carbohydrate gum [cellulose], glycerin, sodium alginate, stearic acid), vegetable grade magnesium stearate (lubricant).


Contains no artificial colours, preservatives, or sweeteners; no dairy, starch, sugar, wheat, gluten,yeast, soy, corn, egg, fish, shellfish, animal products,salt, tree nuts, or GMOs. Suitable for vegetarians/vegans.


Consult a health care practitioner prior to use if you are pregnant or breastfeeding or are taking carbidopa or drugs/supplements with serotonergic activity. Some people may experience diarrhea, nausea, vomiting, abdominal pain or drowsiness. Exercise caution if operating heavy machinery, driving a motor vehicle or involved in activities requiring mental alertness. Discontinue use and consult a health care practitioner if you show signs of weakness, oral ulcers or abdominal pain accompanied by severe muscle pain, if you experience skin changes, or if symptoms persist or worsen. Consult a health care practitioner if sleeplessness persists for more than 3 weeks. Do not use if you have scleroderma. Keep out of reach of children.

Drug Interactions

Combining serotonergic drugs such as antidepressants, dextromethorphan (in cough syrups), meperidine (Demerol), tramadol and others may increase the risk of serotonergic side effects such as serotonin syndrome.12 Combining 5-HTP and carbidopa-levodopa (Sinement®) can increase the risk of serotonergic side effects. Carbidopa is sometimes intentionally used with 5-HTP to minimize peripheral 5-HTP metabolism and boost the amount that reaches the brain. But this combination might also increase the risk of some side effects including hypomania, restlessness, rapid speech, anxiety, insomnia, and aggressiveness. The combination of 5-HTP and carbidoba has also resulted in scleroderma-like skin reactions.13,14 Individuals using this drug combination or those who suffer from scleroderma should be monitored by a health care practitioner. Anecdotally, 5-HTP may lower blood pressure and could be additive to antihypertensive drugs.

  1. Birdsall TC. 5-Hydroxytryptophan: a clinically-effective serotonin precursor. Altern Med Rev. 1998;3(4):271-80.
  2. 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(2):53-81.
  3. Nicolodi M, Sicuteri F. Fibromyalgia and migraine, two faces of the same mechanism. Serotonin as the common clue for pathogenesis and therapy. Adv Exp Med Biol. 1996;398:373-9.
  4. Sarzi Puttini P, Caruso I. Primary fibromyalgia syndrome and 5-hydroxy-L-tryptophan: a 90-day open study. J Int Med Res. 1992;20(2):182-9.
  5. Caruso I, Sarzi Puttini P, Cazzola M, Azzolini V. Double-blind study of 5-hydroxytryptophan versus placebo in the treatment of primary fibromyalgia syndrome. J Int Med Res. 1990 May-Jun;18(3):201-9.
  6. Wyatt RJ, Zarcone V, Engelman K, Dement WC, Snyder F, Sjoerdsma A. Effects of 5-hydroxytryptophan on the sleep of normal human subjects. Electroencephalogr Clin Neurophysiol. 197 Jun;30(6):505-9.
  7. Wurtman RJ, Wurtman JJ. Brain serotonin, carbohydrate-craving, obesity and depression. Adv Exp Med Biol. 1996;398:35-41.
  8. Ceci F, Cangiano C, Cairella M, Cascino A, Del Ben M, Muscaritoli M, Sibilia L, Rossi-Fanelli F. The effects of oral 5-hydroxytryptophan administration on feeding behaviour in obese adult female subjects. J Neural Transm. 1989;76(2):109-117.
  9. Cangiano C, Ceci F, Cairella M, Cascino A, Del Ben M, Laviano A, Muscaritoli M, Rossi-Fanelli F. Effects of 5-hydroxytryptophan on eating behaviour and adherence to dietary prescriptions in obese adult subjects. Adv Exp Med Biol. 1991;294: 591-593.
  10. Cangiano C, Ceci F, Cascino A, Del Ben M, Laviano A, Muscaritoli M, Antonucci F, Rossi-Fanelli F. Eating behavior and adherence to dietary prescriptions in obese adult subjects treated with 5-hydroxytryptophan, Am J Clin Nutr. 56: 863-867;1992.
  11. Shaw K, Turner J, Del Mar C. Tryptophan and 5-hydroxytryptophan for depression. Cochrane Database Syst Rev. 2002;(1):CD003198.
  12. Singhal AB, Caviness VS, Begleiter AF, Mark EJ, Rordorf G, Koroshetz WJ. Cerebral vasoconstriction and stroke after use of serotonergic drugs. Neurology. 2002 Jan 8;58(1):130-3.
  13. Sternberg EM, Van Woert MH, Young SN, Magnussen I, Baker H, Gauthier S, Osterland CK. Development of a scleroderma-like illness during therapy with L-5-hydroxytryptophan and carbidopa. N Engl J Med. 1980 Oct 2;303(14):782-7.
  14. Joly P, Lampert A, Thomine E, Lauret P. Development of pseudobullous morphea and scleroderma-like illness during therapy with L-5-hydroxytryptophan and carbidopa. J Am Acad Dermatol. 1991 Aug;25(2 Pt 1):332-3.