NutriStack
5-HTP and MDMA, contraindicated.
Taking 5-HTP with MDMA sharply increases the risk of serotonin syndrome, a potentially life-threatening state of excess serotonergic activity with agitation, high fever, rapid heart rate, muscle rigidity, and seizures.
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
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What the row says.
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At a glance
- Pair type
- Contraindicated
- Evidence (highest tier)
- Moderate
- Source citations
- 2 sources
- Stack Score effect
- −25 to your Stack Score (per scored contraindication row).
- Scope
- Supplement × Supplement
- Last verified
- May 30, 2026
Contraindicated · Moderate evidence
Contraindicated
What is happening. Taking 5-HTP with MDMA sharply increases the risk of serotonin syndrome, a potentially life-threatening state of excess serotonergic activity with agitation, high fever, rapid heart rate, muscle rigidity, and seizures.
Mechanism. MDMA causes massive synaptic serotonin release while 5-HTP supplies extra precursor that boosts serotonin synthesis, and the combined surge can overwhelm serotonergic regulation and trigger serotonin syndrome.
Recommendation. Do not combine. If symptoms such as high fever, confusion, severe muscle stiffness, or rapid heartbeat develop, seek emergency medical care immediately.
Stack Score
How this pair moves the number.
Effect on the composite score
If both 5-HTP and MDMA 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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