5-HTP

What is 5-HTP?

5-hydroxytryptophan (5-HTP) is a compound the body makes from the amino acid tryptophan. It is the direct precursor of serotonin, a brain messenger involved in mood, and serotonin in turn is used to make melatonin. Supplement 5-HTP is usually extracted from the seeds of the African plant Griffonia simplicifolia.

What the research says

Because 5-HTP sits on the path to serotonin and melatonin, it is often included in sleep and mood formulas. Human evidence for sleep is thin. NCCIH notes that tryptophan and 5-HTP have sedative effects but that it is unclear how they work and there is very limited data on their effects on insomnia. The American Academy of Sleep Medicine suggests clinicians not use tryptophan for chronic insomnia (NCCIH).

One of the few recent trials randomized 30 older adults in Singapore to 100 mg of 5-HTP daily or no supplement for 12 weeks. The study was single-blinded and small. Poor sleepers taking 5-HTP improved their global sleep quality score, and blood serotonin rose (Clin Nutr, 2024). Larger, placebo-controlled trials are needed before firm conclusions can be drawn.

On safety, a 2004 review examined concerns that 5-HTP could cause eosinophilia-myalgia syndrome, a serious condition linked in 1989 to contaminated L-tryptophan from one manufacturer. The authors found no definitive cases of toxicity from 5-HTP and no similar contaminants in the samples analyzed (Toxicol Lett). Quality control still matters.

It is worth separating 5-HTP from melatonin. Melatonin acts directly as a timing signal, while 5-HTP must first be converted to serotonin and then, in the pineal gland, to melatonin. How much of a supplement dose follows that path at night is not well understood, and much of the 5-HTP research has focused on mood rather than sleep. For people whose main problem is waking in the early morning, there is no direct evidence that 5-HTP helps.

How it’s used in supplements

5-HTP is sold alone in capsules, often at 50 to 100 mg, and in blended sleep and mood products where the dose is frequently not listed. Reported side effects include nausea, heartburn, gas and drowsiness.

The most important caution is interactions. 5-HTP adds to serotonin activity, so combining it with antidepressants (SSRIs, SNRIs, MAOIs), triptans for migraine, tramadol, dextromethorphan or St. John’s wort may raise the risk of serotonin toxicity. NCCIH warns about this risk for L-tryptophan supplements used with serotonin-affecting medicines. It may also add to the effect of sedatives. Avoid 5-HTP in pregnancy and breastfeeding unless a doctor advises it, and talk to your doctor before use if you take any prescription medicine.