Last Updated: July 22, 2023

5-HTP is the precursor to serotonin, which is often described as the neurotransmitter responsible for happiness. 5-HTP has successfully been used to restore serotonin levels in people with depression and other conditions.

5-HTP is most often used for

What is 5-HTP?

5-HTP is a precursor to serotonin and a byproduct of tryptophan. Plants are a rich source of 5-HTP, and Griffonia simplicifolia is often used for the extraction and the commercial production of 5-HTP.[1] 5-HTP supplementation is used to increase levels of serotonin in the body and has been shown to be effective in treating conditions like depression. It has also shown efficacy for regulating sleep and appetite.[2]

What are 5-HTP’s main benefits?

5-HTP is very reliable for increasing serotonin levels, and shows potential for treating depression.[2] A study comparing the efficacy of 5-HTP to fluvoxamine found that 5-HTP performed as well as fluvoxamine in terms of antidepressant effects.[3] While this is promising, more research is needed to confirm these effects.

A study that involved participants with sleep disorders using an amino acid combination of 5-HTP and GABA, along with other ingredients, noted a decrease in the time it took participants to fall asleep, as well as improvements in overall sleep duration and quality.[4]

5-HTP may play a role in weight loss, as researchers have observed weight loss due to an increase in satiety, or the feeling of fullness, after supplementation. One study noted an increase in satiety and reduced binge eating tendencies in women with overweight or obesity.[5] Another study differentiated the effects of 5-HTP, stating it increased satiety, but had no significant effect on appetite suppression.[6]

What are 5-HTP’s main drawbacks?

At high doses (100–200 mg per kg of body weight), 5-HTP has been associated with serotonin syndrome in lab animals, a severe condition caused by high levels of serotonin in the body.[7] There are no reported toxicity reports at normal doses, and it should be noted that serotonin syndrome from 5-HTP supplementation has not been observed in humans.[7]

How does 5-HTP work?

5-HTP increases serotonin levels in the body, which may improve conditions caused by low serotonin levels. Serotonin is a neurotransmitter that plays a role in regulating mood, sleep, memory, and various other processes.[1]

What else is 5-HTP known as?
Note that 5-HTP is also known as:
  • 5-hydroxytryptophan
  • serotonin precursor
Dosage information

A typical dose of 5-HTP is in the range of 300-500 mg, taken either once daily or in divided doses. Lower doses may also be effective, although usually when paired with other substances.

For the purpose of reducing food intake, 5-HTP should be taken with a meal as it increases satiety from food intake (rather than reducing appetite/hunger).

5-HTP should not be taken with any neurological drug that has been prescribed for antidepressant or other cognitive purposes unless cleared by a medical doctor. This is most important for SSRI usage, wherein the combination with 5-HTP is potentially lethal.

Examine Database: 5-HTP
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The information in this section is slated for renovation — it will soon be transformed into a more usable (and readable!) form in the coming months. As such, the text in this section may be out of date and not up to Examine’s current standards for writing style.

Examine Database References
  1. Weight - Ceci F, Cangiano C, Cairella M, Cascino A, Del Ben M, Muscaritoli M, Sibilia L, Rossi Fanelli FThe effects of oral 5-hydroxytryptophan administration on feeding behavior in obese adult female subjectsJ Neural Transm.(1989)
  2. Weight - Cangiano C, Ceci F, Cascino A, Del Ben M, Laviano A, Muscaritoli M, Antonucci F, Rossi-Fanelli FEating behavior and adherence to dietary prescriptions in obese adult subjects treated with 5-hydroxytryptophanAm J Clin Nutr.(1992 Nov)
  3. Sleep Terrors - Bruni O, Ferri R, Miano S, Verrillo EL -5-Hydroxytryptophan treatment of sleep terrors in childrenEur J Pediatr.(2004 Jul)
  4. Appetite - Cangiano C, Laviano A, Del Ben M, Preziosa I, Angelico F, Cascino A, Rossi-Fanelli FEffects of oral 5-hydroxy-tryptophan on energy intake and macronutrient selection in non-insulin dependent diabetic patientsInt J Obes Relat Metab Disord.(1998 Jul)
  5. Cortisol - Schruers K, van Diest R, Nicolson N, Griez EL-5-hydroxytryptophan induced increase in salivary cortisol in panic disorder patients and healthy volunteersPsychopharmacology (Berl).(2002 Jun)