NutriStack
5-HTP and Psilocybin, a caution.
5-HTP increases serotonin synthesis and, combined with the serotonergic psychedelic psilocybin, raises the theoretical risk of excessive serotonergic stimulation.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
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From the interaction database
What the row says.
Every entry follows the same shape: what is happening, the mechanism, the recommendation, and the primary literature.
At a glance
- Substances
- 5-HTP and Psilocybin
- Pair type
- Caution
- Evidence (highest tier)
- Emerging
- Source citations
- 2 sources
- Stack Score effect
- −5 to your Stack Score (per scored caution row).
- Scope
- Supplement × Supplement
- Last verified
- May 30, 2026
Caution · Emerging evidence
Caution
What is happening. 5-HTP increases serotonin synthesis and, combined with the serotonergic psychedelic psilocybin, raises the theoretical risk of excessive serotonergic stimulation.
Mechanism. 5-HTP is the immediate precursor to serotonin and boosts serotonin levels, while psilocin acts as a 5-HT2A agonist, so the two can additively increase serotonergic signaling.
Recommendation. Do not combine. Seek medical advice before using either agent if the other is in use.
Sources (2)
- Halman A et al. Drug-drug interactions involving classic psychedelics: A systematic review. J Psychopharmacol. 2024. PMID 37982394
- Turner EH et al. Serotonin a la carte: supplementation with the serotonin precursor 5-hydroxytryptophan. Pharmacology and Therapeutics, 2006
Stack Score
How this pair moves the number.
Effect on the composite score
If both 5-HTP and Psilocybin are in the same stack, this pair applies −5 to your Stack Score (per scored caution row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
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