Compound or practice · Sleep
L-Tryptophan / 5-HTP
Serotonin/melatonin precursors with modest sleep-and-mood signals — and the sharpest serotonergic-drug caution on the shelf.
- Overall grade
- Grade C
- Last revised
- 2
- graded outcomes
- 0
- references listed
A structured monograph in Prometheus's bundled library. Its grades are the monograph's own reading of the evidence, not a peer-reviewed review.
2 at grade C — 2 graded rows
What is known
Each outcome with its grade (how strong the evidence is, A to D), the size of the effect where the entry records one, and how often studies agree.
- Sleep latencyEvidence grade C
Modest
Smallmixed
- Mood / anxiety (5-HTP)Evidence grade C
Limited quality
Smallmixed
What is uncertain
Read off the same rows as above. Nothing here is added that the entry does not itself record.
- Thin evidence: Sleep latency (grade C); Mood / anxiety (5-HTP) (grade C).
- Caution with SSRIs / SNRIs: Serotonin-syndrome risk — do not combine without a prescriber.
Interactions
Documented pairings with supplements and medicines. A medicine on this list is a conversation for whoever prescribes it.
SSRIs / SNRIsCaution
Serotonin-syndrome risk — do not combine without a prescriber.
The evidence in words
What it is
L-tryptophan is the essential amino acid precursor to serotonin and melatonin; 5-HTP is the intermediate one step closer to serotonin.
How it works
Supplying precursor can raise serotonin and downstream melatonin, plausibly aiding sleep onset and mood.
What the evidence shows
Small studies suggest modest benefits for sleep latency and mood, stronger for 5-HTP in some anxiety/depression trials, but quality is limited. The dominant consideration is safety: combined with SSRIs, SNRIs, MAOIs, or other serotonergic agents, these precursors risk serotonin syndrome.
How to use it
Tryptophan 1–3 g or 5-HTP 100–300 mg before bed — only after confirming you take no serotonergic medication.
Safety & interactions
The serotonergic-drug interaction is the headline risk. Historical contamination concerns with tryptophan underscore buying reputable products. ssri — Serotonin-syndrome risk — do not combine without a prescriber.
Bottom line
Modest for sleep and mood, and the single riskiest common supplement to combine with antidepressants. Never stack with serotonergic drugs.
How it is used
As the entry records it, from the studies it summarises. Not a recommendation for you — doses that suit a trial population may not suit you.
- Standard
- Tryptophan 1–3 g or 5-HTP 100–300 mg pre-bed.
Related reading
Entries that share this one's tags or conditions.
- L-Tryptophan / 5-HTP for Mood / anxiety (5-HTP)Evidence grade C — Limited qualityEvidence grade C
- L-Tryptophan / 5-HTP for Sleep latencyEvidence grade C — ModestEvidence grade C
- L-Tryptophan / 5-HTP: dosage and how to take itTryptophan 1–3 g or 5-HTP 100–300 mg pre-bed.Evidence grade C
- L-Tryptophan / 5-HTP: side effects, safety & interactionsThe serotonergic-drug interaction is the headline risk. Historical contamination concerns with tryptophan underscore buyEvidence grade C
Sources
This entry lists no references of its own.
Last revised . A grade is this entry's reading of the evidence, not medical advice.