The short answer
Nortriptyline specifically warns about serotonin syndrome with tryptophan. Review concentrated L-tryptophan supplements before use; this does not justify avoiding ordinary protein foods.
What this answer covers
Supplemental oral L-tryptophan, not dietary protein or L-5-HTP.
- Supplement or preparation
- L-Tryptophan
- Medication ingredient
- nortriptyline
The medicine label names tryptophan
Nortriptyline lists tryptophan among serotonergic products that can increase concern for serotonin syndrome during co-use.
Supplement amounts differ from food
The warning concerns adding a concentrated precursor. It does not instruct patients to eliminate normal protein foods.
Make additions a supervised decision
Review the product and amount before use, including other mood supplements. Do not infer that separating the supplement and medicine makes co-use safe.
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 serotonin precaution follows the exact medicine label; no protective spacing or universal safe supplement dose established.
- Exact scope
- Supplemental oral L-tryptophan, not dietary protein or L-5-HTP. with Exact oral nortriptyline hydrochloride capsules. RxNorm IN 7531/PIN 203130 hydrochloride. A nortriptyline measurement during amitriptyline use represents a metabolite exposure, not directly prescribed nortriptyline.
- Medication form and route
- oral
- Timing or duration
- Source-specific single-dose, repeated-dose and observational exposures distinguished.
What remains uncertain
- Captured literature does not provide an exact oral-pair event rate or nutritional restriction.
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 nortriptyline.
Exact label names tryptophan and St John’s wort in serotonin-syndrome warnings; CYP2D6, cardiovascular and anticholinergic interactions require individual review.
How this applies: RxNorm IN 7531/PIN 203130 hydrochloride. A nortriptyline measurement during amitriptyline use represents a metabolite exposure, not directly prescribed nortriptyline.
No universal supplement interval, event rate or preparation equivalence established. Original label distinguishes warnings from measured pair-specific results.
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: 12bf7a1cc29330b6
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.