5-HTP
5-HTP (5-hydroxytryptophan) is an amino acid derivative the body makes from tryptophan on the way to serotonin and melatonin. Supplements are usually made from Griffonia seeds.
Also listed as 5-hydroxytryptophan, HTP, 5HTP
What it is studied for
The strongest rated effects first. Bars show the size of the effect, the letter grades the evidence, and each rating lists the studies behind it.
What is 5-HTP?
5-HTP is an intermediate in the pathway from tryptophan to serotonin and melatonin. Supplements commonly use Griffonia seeds as their source. That biological role explains the interest in sleep and mood, but does not by itself predict treatment benefit. 1
Key studies
The most recent publications linked to 5-HTP's ratings.
Why people take it
SuppCo community snapshot, 2026-09-28. Reasons for use are not evidence that it works.
Questions people ask
Is 5-HTP a substitute for an antidepressant?
The small, inconclusive depression evidence does not establish it as an equivalent treatment. 2
Was the sleep trial a placebo comparison?
No. It compared supplementation with a control group receiving no 5-HTP. 3
Does 750 mg represent a recommended daily dose?
No. It was the experimental dose in a short diabetes study. 4
Can a Griffonia extract be compared by milligrams alone?
No. Its 5-HTP concentration also matters. 5
Tryptophan