The short answer
Review L-5-HTP before combining it with trimipramine. Official L-5-HTP guidance advises against antidepressant co-use.
What this answer covers
Concentrated oral L-5-HTP; distinct from the other serotonin precursor and ordinary food protein.
- Supplement or preparation
- L-5-HTP
- Medication ingredient
- trimipramine
Why review is advised
Health Canada advises not to use L-5-HTP with antidepressants. Trimipramine is an antidepressant.
Keep precursor identities separate
L-5-HTP is not L-tryptophan, and whole seed preparations do not establish a measured L-5-HTP dose.
A time gap is not established protection
Discuss the product and amount with the prescriber before adding it. These sources give no validated supplement gap or universal safe dose.
Recognize concerning symptoms
Seek urgent medical care for a combination of agitation or confusion, fever or heavy sweating, tremor, muscle rigidity or repeated twitching. These can be signs of serotonin syndrome; a single nonspecific symptom does not establish the diagnosis.
Evidence and practical considerations
Side effects & toxicity
Conditional review follows explicit supplement guidance.
- Exact scope
- Concentrated oral L-5-HTP; distinct from the other serotonin precursor and ordinary food protein. with Exact oral trimipramine maleate capsules. RxNorm IN10834 / PIN71532 maleate; mesylate PIN236189 is distinct. Oral maleate capsules only.
- Medication form and route
- oral
- Timing or duration
- Source-specific single-dose, repeated-dose and observational exposures distinguished.
What remains uncertain
- No exact-pair clinical event rate, universal safe supplement dose or protective spacing established.
Factors that may matter: preparation and plant part; clinical indication; dose; other medicines; baseline alertness.
Read the supporting source summaries
Source 1: current product label
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People prescribed oral trimipramine.
Label describes a sedative component and explicitly names tryptophan and St John’s wort in serotonin warnings. Cardiovascular and anticholinergic precautions apply.
How this applies: RxNorm IN10834 / PIN71532 maleate; mesylate PIN236189 is distinct. Oral maleate capsules only.
No universal supplement interval, event rate or preparation equivalence established.
Source 2: official product guidance
webprod.hc-sc.gc.ca · Source check Sep 10, 2026
Population: Adults considering oral L-5-HTP.
Advises not to use with antidepressants; gives serotonergic product precautions and drowsiness caution.
How this applies: The requested medicine is an antidepressant; this is a product-label precaution, not exact-pair clinical proof.
Does not quantify risk with each specific antidepressant or establish a safe supplement dose.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Article prepared | |
| Current exact available claims adjudicated using original captures and explicit identity and comparator limits. | |
| Research summary published |
Article revision: a49f8c1788c6d335
This guide brings together the evidence records used by our interaction checker. Each finding retains its own preparation limits, research date, and source summaries.
Full citations require verification. Reading this answer and the source summaries does not.
Taking other supplements or medications?
Use the checker to explore your other combinations. Ask a pharmacist to review the exact products, amounts and medical conditions in your complete list.
Open the interaction checkerInformation, not medical advice. Do not change prescribed treatment based on this guide.