NutriStack
5-HTP and Selegiline, contraindicated.
5-HTP increases serotonin synthesis while Selegiline reduces monoamine breakdown. Combining them can cause dangerous serotonergic excess and serotonin syndrome.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
Same shape as the other 1,729 pairs in the public database.
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 Selegiline
- Pair type
- Contraindicated
- Evidence (highest tier)
- Strong
- Source citations
- 1 source
- Stack Score effect
- −25 to your Stack Score (per scored contraindication row).
- Scope
- Supplement × Prescription
- Last verified
- May 30, 2026
Contraindicated · Strong evidence
Contraindicated
What is happening. 5-HTP increases serotonin synthesis while Selegiline reduces monoamine breakdown. Combining them can cause dangerous serotonergic excess and serotonin syndrome.
Mechanism. 5-HTP bypasses tryptophan hydroxylase to increase serotonin production; MAOIs inhibit serotonin breakdown.
Recommendation. Do NOT combine 5-HTP with Selegiline. Use only if the prescriber managing Selegiline explicitly directs it and provides washout instructions.
Sources (1)
Stack Score
How this pair moves the number.
Effect on the composite score
If both 5-HTP and Selegiline are in the same stack, this pair applies −25 to your Stack Score (per scored contraindication row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
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