Risk of serotonin syndrome
5-HTP is a direct serotonin precursor. Combined with SSRIs (which prevent serotonin reuptake), can cause dangerous serotonin excess. Serotonin syndrome symptoms: agitation, hyperthermia, tremor, rigid muscles, potentially fatal.
Do NOT combine 5-HTP with any SSRI, SNRI, or MAOI. Life-threatening interaction.
Never combine - no safe timing
Risk of serotonin syndrome. Do NOT combine 5-HTP with any SSRI, SNRI, or MAOI. Life-threatening interaction.
Never combine - no safe timing
This interaction is rated “Danger” by Formulate. 5-HTP is a direct serotonin precursor. Combined with SSRIs (which prevent serotonin reuptake), can cause dangerous serotonin excess. Serotonin syndrome symptoms: agitation, hyperthermia, tremor, rigid muscles, potentially fatal.
Studies from our registry that mention 5-htp or ssri. Each links to the primary source and the other Formulate pages citing it.
Mentions ssri · 2024
St. John's Wort — StatPearls
Primary literature · Monograph
Identifies SSRIs (sertraline, paroxetine, fluoxetine, citalopram) as high-concern co-administration targets due to serotonin syndrome risk. Typical SJW doses implicated: 600-900 mg/day standardized extract. Typical SSRI doses in case reports: 20-75 mg/day.
Mentions ssri · 2015
Rhodiola rosea versus sertraline for major depressive disorder: a randomized placebo-controlled trial
Mao JJ, Xie SX, Zee J, et al. · Phytomedicine
12-week three-arm RCT (n=57) found rhodiola produced smaller antidepressant effect than sertraline but with significantly fewer adverse events, supporting it as an option for milder depression.
Other interactions to know
Combining St John's wort with any SSRI risks serotonin syndrome — a potentially fatal hyperserotonergic state.
SAM-e with SSRIs: Serotonin syndrome risk
Tyrosine and 5-HTP compete for brain uptake
Both increase serotonin - risk of excess
Melatonin may enhance SSRI side effects
Rhodiola may have mild MAOI effects
Ashwagandha may enhance SSRI effects
Check your full stack in the free interaction checker.
The free checker lets you add any combination of supplements and medications at once. The free web app goes further — every stack change surfaces interaction alerts automatically.
Medical disclaimer. This page is for educational purposes only and does not replace advice from a qualified healthcare provider.
Last medically reviewed: