Amino Acids & Proteins

5-HTP

Also known as: 5-Hydroxytryptophan, Griffonia simplicifolia extract, Oxitriptan

The serotonin precursor from an African seed — modest mood and sleep evidence, with a serious antidepressant interaction warning.

By IngredientWiki Editorial Team
Fact-checked by IngredientWiki Editorial Team
Updated 2026-09-26
2 min read

In short

5-HTP (5-hydroxytryptophan) is the immediate precursor to serotonin, the neurotransmitter central to mood, sleep, and appetite. It is extracted from the seeds of Griffonia simplicifolia and, unlike tryptophan, crosses into the brain efficiently. Trials show modest benefits for depression and sleep, but the critical caveat is safety: combining 5-HTP with antidepressants — especially SSRIs — can trigger serotonin syndrome, a potentially dangerous reaction.

Direct precursor to serotonin
Extracted from Griffonia simplicifolia seeds
Modest trial evidence for mood and sleep
DANGER: never combine with SSRIs or MAOIs — serotonin syndrome risk

What is 5-HTP?

5-HTP sits one step from serotonin — the last intermediate before the body manufactures the neurotransmitter itself. That directness is both its appeal and its risk: it raises serotonin more predictably than tryptophan, producing measurable mood and sleep effects in trials, but it also stacks with the serotonin-raising effects of antidepressants. Used responsibly as a standalone supplement, it is a modest, useful tool; combined carelessly with medication, it becomes dangerous.

Where it comes from

Natural sources

Seeds of Griffonia simplicifolia, a West African shrub
The body makes 5-HTP from dietary tryptophan (turkey, eggs, nuts)
Sold as extract capsules standardized to 5-HTP content

How it's made

Supplemental 5-HTP is extracted from Griffonia seeds, not synthesized.

What it does in products

Benefits

Depression support

moderate evidence

Meta-analyses of older trials found 5-HTP improved depression symptoms, though study quality is mixed and modern trials are few — promising but not definitive.

Sleep quality

moderate evidence

Because serotonin converts to melatonin, 5-HTP modestly improves sleep onset and quality in some trials, especially when taken in the evening.

Appetite regulation

emerging evidence

Serotonin signaling suppresses appetite; some studies found reduced calorie intake with 5-HTP — interesting but preliminary.

Side effects & safety

Nausea and stomach discomfort (common)Most common early; taking with food and starting low reduces it.

Serotonin syndrome when combined with serotonergic drugs (rare)Confusion, agitation, sweating, and muscle twitching — a medical emergency; never combine with SSRIs, SNRIs, or MAOIs.

Safety considerations

Insufficient safety data in pregnancy; avoid use.
CRITICAL: SSRIs, SNRIs, MAOIs, and other serotonergic drugs — serotonin syndrome risk.
Adds to sedative effects of sleep aids and alcohol.
May interact with carbidopa (Parkinson's treatment).
Not for: Current or recent SSRI/SNRI/MAOI use
Not for: Pregnancy and breastfeeding
Not for: Heart valve conditions (theoretical serotonin-related concern)

How it's used

In supplements

Typical doses: 50–100 mg one to three times daily, or 100–300 mg at night for sleep. Start at 50 mg and assess over 2–4 weeks. Never stack with antidepressants.

Regulatory status

Dietary supplement under DSHEA; in several European countries, 5-HTP is a licensed medicine for depression — an indication the US supplement market cannot legally claim.

The serotonin syndrome red line

Serotonin syndrome occurs when serotonin signaling overloads the nervous system, causing symptoms from sweating and agitation to seizures in severe cases. The classic trigger is combining multiple serotonin-raising agents — and 5-HTP is a direct serotonin precursor. Because antidepressants often work through the same pathway, the rule is absolute: if you take an SSRI, SNRI, MAOI, or St. John's wort, 5-HTP is off the table unless a specialist supervises. Even supplements can stack dangerously.

Frequently asked questions

Does 5-HTP really work for depression?

The trial evidence is real but dated and of mixed quality — several older studies show benefit comparable to some antidepressants, while modern replication is lacking. It is not a substitute for professional mental-health care.

When should I take 5-HTP — morning or night?

For sleep, take 100–300 mg about 30–60 minutes before bed. For daytime mood support, split smaller doses with meals. Serotonin's conversion to melatonin makes evening dosing the most common protocol.

Can I take 5-HTP with other supplements?

Generally yes with non-serotonergic supplements, but avoid stacking with St. John's wort, SAM-e, or other serotonin-affecting botanicals. If you take any prescription medication, check with a pharmacist first.

The bottom line

5-HTP is a legitimate serotonin precursor with modest mood and sleep evidence — and one non-negotiable rule: it never mixes with antidepressants. Start low, use it standalone or with medical guidance, and respect the serotonin-system ceiling.

References

5-HTP and depression — literature search. PubMed (National Library of Medicine). https://pubmed.ncbi.nlm.nih.gov/?term=5-hydroxytryptophan+depression+randomized
5-HTP compound summary. PubChem (National Library of Medicine). https://pubchem.ncbi.nlm.nih.gov/compound/439280
5-HTP and sleep — literature search. PubMed (National Library of Medicine). https://pubmed.ncbi.nlm.nih.gov/?term=5-hydroxytryptophan+sleep
Serotonin syndrome (review). PubMed (National Library of Medicine). https://pubmed.ncbi.nlm.nih.gov/?term=serotonin+syndrome+review