5-HTP (5-Hydroxytryptophan)

Amino Acidoral · inferred

Direct precursor to serotonin that crosses the blood-brain barrier. Used for mood support and sleep. Should not be combined with SSRIs.

Projected serum levels — 100 mg, once daily

Maintenance schedule: 100 mg once daily (oral).

Modeled steady state after ~1 days: peak ≈ 44.8 mg, trough ≈ 0.30 mg body load. Population-based estimate over 15 days for a 100 mg dose at a 70 kg reference body mass — the interactive app scales curves to your doses, timing, and body mass.

Key facts

Category: Amino Acid
Route modeled: Oral
Model confidence: inferred
Half-life: 2.2 h
Common dose: 100 mg
Suggested maximum: 300 mg/day
Reference dose range: 50–300 mg (single dose)
Suggested cadence: once daily
Validated against: 200 mg oral — Cmax 1 mg/L at 2 h

Documented interactions

danger
1P-LSD (1-Propionyl-LSD) + 5-HTP (5-Hydroxytryptophan) Serotonin risk
1P-LSD (1-Propionyl-LSD) and 5-HTP (5-Hydroxytryptophan) both have serotonergic activity. Risk of serotonin syndrome (hyperthermia, rigidity, autonomic instability, altered mental status).
danger
25I-NBOMe + 5-HTP (5-Hydroxytryptophan) Serotonin risk
25I-NBOMe and 5-HTP (5-Hydroxytryptophan) both have serotonergic activity. Risk of serotonin syndrome (hyperthermia, rigidity, autonomic instability, altered mental status).
danger
2C-I (2,5-Dimethoxy-4-iodophenethylamine) + 5-HTP (5-Hydroxytryptophan) Serotonin risk
2C-I (2,5-Dimethoxy-4-iodophenethylamine) and 5-HTP (5-Hydroxytryptophan) both have serotonergic activity. Risk of serotonin syndrome (hyperthermia, rigidity, autonomic instability, altered mental…
danger
2C-B (4-Bromo-2,5-dimethoxyphenethylamine) + 5-HTP (5-Hydroxytryptophan) Serotonin risk
2C-B (4-Bromo-2,5-dimethoxyphenethylamine) and 5-HTP (5-Hydroxytryptophan) both have serotonergic activity. Risk of serotonin syndrome (hyperthermia, rigidity, autonomic instability, altered mental…
danger
4-AcO-DMT (Psilacetin) + 5-HTP (5-Hydroxytryptophan) Serotonin risk
4-AcO-DMT (Psilacetin) and 5-HTP (5-Hydroxytryptophan) both have serotonergic activity. Risk of serotonin syndrome (hyperthermia, rigidity, autonomic instability, altered mental status).
danger
5-MeO-DMT (5-Methoxy-N,N-dimethyltryptamine) + 5-HTP (5-Hydroxytryptophan) Serotonin risk
5-HTP (5-Hydroxytryptophan) and 5-MeO-DMT (5-Methoxy-N,N-dimethyltryptamine) both have serotonergic activity. Risk of serotonin syndrome (hyperthermia, rigidity, autonomic instability, altered mental…

Serum checks 78 modeled interaction pairings for 5-htp (5-hydroxytryptophan) across your whole stack — absorption conflicts, enzyme inhibition, and nutrient depletion included.

Research behind this entry

Oral 5-hydroxytryptophan versus fluoxetine: a comparative study of efficacy in the treatment of depression Jangid P et al. · Asian Journal of Psychiatry, 2013 DOI
Head-to-head RCT found 5-HTP showed comparable antidepressant efficacy to fluoxetine over 8 weeks in patients with first-episode depression.
Effect of a serotonin precursor and uptake inhibitor in anxiety disorders: a double-blind comparison of 5-hydroxytryptophan, clomipramine and placebo Kahn RS et al. · International Clinical Psychopharmacology, 1987 DOI
Double-blind trial found 5-HTP significantly reduced anxiety in patients with anxiety disorders, with effects comparable to the tricyclic antidepressant clomipramine.
Kinetics of l-5-hydroxytryptophan in healthy subjects. Westenberg HG, Gerritsen TW, Meijer BA, van Praag HM · Psychiatry research, 1982 DOI
This citation reports a human primary study involving 5-HTP (5-Hydroxytryptophan). It does not by itself establish a qualified dose, safety profile, efficacy claim, or pharmacokinetic route for this record.

3 published studies referenced in the app, each with a plain-language summary.