5-hydroxytryptophan
5-HTP
What it is5-hydroxytryptophan, the immediate precursor of serotonin, bypassing the rate-limiting hydroxylase.
Why it mattersRaises serotonin without tryptophan hydroxylase; sold as an antidepressant supplement for this reason.
What it changes⚑ Serotonin syndrome with SSRIs and MAOIs; peripheral conversion causes nausea unless carbidopa is co-given.
Used for
- dietary supplement (serotonin precursor; no approved indication)
- depression (weak evidence)
- insomnia
- fibromyalgia
NO BOXED WARNINGS
Principal riskSerotonin syndrome with SSRIs and MAOIs
Classes and tags
Available strengths
- cap 50, 100, 200 mg
Cost
5-hydroxytryptophan (5-HTP)
| Strength | #/mo | generic $/mo | CostPlus | |
|---|---|---|---|---|
| 50 mg | cap | 30 qd | not offered | |
| 100 mg | cap | 30 qd | not offered | |
| 200 mg | cap | 30 qd | not offered |
NADAC is a voluntary CMS survey of what retail community pharmacies pay for the drugs they stock. 5-hydroxytryptophan is dispensed outside retail pharmacies, so it rarely appears on surveyed invoices.
Active metabolites
Open 5-hydroxytryptophan in the interactive console ↗
Self-check
- Which enzyme does 5-HTP bypass?
Tryptophan hydroxylase. - What risk arises with 5-HTP plus SSRIs or MAOIs?
Serotonin syndrome.