The short answer
Serotonin syndrome from 5-HTP specifically with hydromorphone has not been established. The supplement and opioid labels still justify reviewing serotonergic co-use, especially when other serotonin-active medicines are present.
What this answer covers
Oral L-5-HTP, not dietary tryptophan; all medicines and supplements need consideration.
- Supplement or preparation
- L-5-HTP
- Medication ingredient
- hydromorphone
The supplement warrants a serotonin review
5-HTP is a serotonin precursor. Its regulatory monograph advises consultation with serotonin-active products, and hydromorphone has a general serotonergic-drug warning. Neither provides an exact-pair risk estimate.
Hydromorphone differs from some other opioids
In a human-transporter experiment, hydromorphone did not inhibit serotonin or noradrenaline transport. This weakens a simple reuptake-inhibition explanation, but does not prove that every combination is safe.
The case report involved another regimen
A report of serious serotonin toxicity involved 5-HTP with sertraline, other products and strenuous exercise. It cannot establish causation for hydromorphone or a safe supplement dose.
Know what needs urgent attention
Review co-use before adding 5-HTP. New agitation or confusion with fever, sweating, tremor or muscle stiffness warrants urgent medical assessment. A few hours of separation is not a proven prevention strategy.
Evidence and practical considerations
Side effects & toxicity
Exact 5-HTP-hydromorphone syndrome not demonstrated; current general cautions retained alongside direct hydromorphone SERT/NET null and confounded other-drug case.
- Exact scope
- Oral L-5-HTP, not dietary tryptophan; all medicines and supplements need consideration. with Hydromorphone RxCUI3423 IN; HCl oral immediate-release, extended-release and injected products distinguished.
- Medication form and route
- oral medication; intravenous medication; intramuscular medication; subcutaneous medication; oral supplement
What remains uncertain
- No unmeasured pair incidence, blanket class transfer or arbitrary spacing interval.
Factors that may matter: Preparation; Dose; Other medicines; Organ function.
Read the supporting source summaries
Source 1: current product label
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People prescribed hydromorphone
Opioid respiratory depression and additive CNS-depressant risk; general serotonergic-drug warning. Constipation can be severe. Hydromorphone is extensively glucuronidated.
How this applies: Exact hydromorphone RxCUI 3423 IN, with stated salt/formulation/route bridge.
No supplement-specific incidence. Oral, injected and extended-release products differ; oral cannabinoid experiments cannot establish every route or formulation.
Source 2: current product label
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People prescribed hydromorphone
Opioid respiratory depression and additive CNS-depressant risk; general serotonergic-drug warning. Constipation can be severe. Hydromorphone is extensively glucuronidated.
How this applies: Exact hydromorphone RxCUI 3423 IN, with stated salt/formulation/route bridge.
No supplement-specific incidence. Oral, injected and extended-release products differ; oral cannabinoid experiments cannot establish every route or formulation.
Source 3: current product label
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People prescribed hydromorphone
Opioid respiratory depression and additive CNS-depressant risk; general serotonergic-drug warning. Constipation can be severe. Hydromorphone is extensively glucuronidated.
How this applies: Exact hydromorphone RxCUI 3423 IN, with stated salt/formulation/route bridge.
No supplement-specific incidence. Oral, injected and extended-release products differ; oral cannabinoid experiments cannot establish every route or formulation.
Source 4: regulatory supplement monograph
webprod.hc-sc.gc.ca · Source check Sep 10, 2026
Population: Adult oral 5-HTP users
Consult before serotonergic co-use; possible drowsiness. Dextromethorphan-containing cough medicine specifically named among serotonergic products.
How this applies: Supplement-specific caution, interpreted with exact opioid evidence.
No measured hydromorphone interaction or safe spacing interval; not a clinical pair trial.
Source 5: original case report
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: One patient.
Serotonin syndrome, rhabdomyolysis and compartment syndrome reported.
How this applies: No hydromorphone; self-adjusted sertraline, other medicines including cyclobenzaprine, uncertain supplement doses and exercise confound attribution.
No hydromorphone; self-adjusted sertraline, other medicines including cyclobenzaprine, uncertain supplement doses and exercise confound attribution.
Source 6: original transporter experiment
pubmed.ncbi.nlm.nih.gov · Source check Sep 10, 2026
Population: Human-transporter cell models, plus separate report review.
Hydromorphone did not inhibit SERT or NET, unlike several other tested opioids.
How this applies: Mechanistic null does not exclude rare toxicity through other mechanisms or override current label cautions. No 5-HTP pair experiment.
Mechanistic null does not exclude rare toxicity through other mechanisms or override current label cautions. No 5-HTP pair experiment.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Article prepared | |
| Prepared exact hydromorphone article with formulation-specific evidence and uncertainty. | |
| Research summary published |
Article revision: bcdb039f13495495
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.