NutriStack
5-HTP and Paroxetine, contraindicated.
5-HTP combined with paroxetine creates dangerous serotonin syndrome risk. Paroxetine is the most potent SERT inhibitor among SSRIs.
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.
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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 Paroxetine
- Pair type
- Contraindicated
- Evidence (highest tier)
- Strong
- Source citations
- 3 sources
- 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 combined with paroxetine creates dangerous serotonin syndrome risk. Paroxetine is the most potent SERT inhibitor among SSRIs.
Mechanism. Paroxetine has the highest SERT binding affinity of all SSRIs. Adding 5-HTP (serotonin precursor) dramatically increases synaptic serotonin, risking serotonin syndrome.
Recommendation. Do NOT take 5-HTP with paroxetine.
Sources (3)
- Boyer EW, Shannon M. The serotonin syndrome. N Engl J Med. 2005;352(11):1112-1120. PMID 15784664
- Truyens M, Lobatón T, Ferrante M et al.. Effect of 5-Hydroxytryptophan on Fatigue in Quiescent Inflammatory Bowel Disease: A Randomized Controlled Trial. Gastroenterology. 2022. PMID 35940251
- Sutanto CN, Xia X, Heng CW et al.. The impact of 5-hydroxytryptophan supplementation on sleep quality and gut microbiota composition in older adults: A randomized controlled trial. Clinical Nutrition. 2024. PMID 38309227
Stack Score
How this pair moves the number.
Effect on the composite score
If both 5-HTP and Paroxetine 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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