Supplement × Supplement·Evidence index
PubMed indexes 8 records that name L-Tryptophan and St. John's Wort together, either in the title or in an interaction, co-administration, or pharmacokinetic context. Each one is listed below with its study design and, where the abstract states one, the authors’ own conclusion, quoted and linked. This page reports that literature. It does not tell you whether to combine them.
Every statement below is attributed to a named, dated, linked source.
This page lists published research relevant to L-Tryptophan and St. John's Wort. It deliberately does not state whether the combination is safe, whether it interacts, in which direction, at what dose, or how far apart to take them.
Strongest relevance first: papers naming both substances in the title, then human trials and systematic reviews.
“The promising therapeutic role of HPL in treating depression is primarily attributed to its regulation of the NFκB-NLRP2-Caspase1-IL1β pathway, specifically by targeting AKK and tryptophan metabolites.”
Names both L-Tryptophan and St. John's Wort in its title.
“The established paradigm of thought views tryptophan primarily as a precursor for auxin and indoleamines, among other metabolites, and mediation of auxin action by the indoleamines as a one-way interaction. We propose that these processes run in both directions with auxin modifying indoleamine biosynthesis and the melatonin:serotonin balance contributing to its effects on plant morphogenesis, and that tryptophan also functions as an inductive signal to mediate diverse…”
Names both L-Tryptophan and St. John's Wort in its title.
“It is concluded that increased tryptophan metabolism toward kynurenine secondary to elevated corticosterone and TNF-α might be one of the pathohphysiological mechanisms that could explain depression like state observed in this rat model. Further, the observed attenuating effect of HP on TNF-α and corticosterone could contribute in its antidepressant effect in this animal model by other ways than their effects on tryptophan-kynurenine metabolism pathway.”
Names both L-Tryptophan and St. John's Wort in its title.
Names both L-Tryptophan and St. John's Wort in its title.
“Our results suggest that the reduction of tryptophan degradation by H. perforatum might be important in the action of the plant as an antidepressant.”
Names both L-Tryptophan and St. John's Wort in its title.
Names both L-Tryptophan and St. John's Wort in its title.
“The antidepressants bupropion and nortriptyline aid long-term smoking cessation. Adverse events with either medication appear to rarely be serious or lead to stopping medication. Evidence suggests that the mode of action of bupropion and nortriptyline is independent of their antidepressant effect and that they are of similar efficacy to nicotine replacement.”
Names L-Tryptophan and St. John's Wort together in an interaction, co-administration, or pharmacokinetic context.
“Numerous interactions between herbal medicines and conventional drugs have been documented. While the significance of many interactions is uncertain, several interactions, particularly those with St John's wort, may have serious clinical consequences.”
Names L-Tryptophan and St. John's Wort together in an interaction, co-administration, or pharmacokinetic context.
Search-based evidence indexes have real limits, and it is worth being explicit about them:
NutriStack is a free iPhone app for organising a supplement routine: what you take, when, and what the published record says about it. Its exploratory interaction checker covers L-Tryptophan, St. John's Wort, and several hundred other substances.
The checker is a research and organisation tool, not a clinical decision aid, and its per-pair assessments are excluded from search until they pass claim-level review.
NutriStack is an informational and organizational tool, not a medical service, and not a substitute for professional advice. Always consult a qualified healthcare professional before starting, stopping, or changing any supplement or medication.
