5-HTP: evidence, dose and safety
5-HTP (5-hydroxytryptophan) is made from the amino acid tryptophan and is a building block of serotonin. Supplements are extracted from the seeds of Griffonia simplicifolia.
At a glance
- Strongest evidence
- C Limited
- Dose in our plans
- 100 mg a day for adults
- Adult upper limit
- 300 mg a day from food and supplements together
- Safety checks
- 3 situations and 2 medicine or supplement interactions, checked against your answers in every plan
- Reviewed
- Atrum Labs clinical team (MD, PhD), November 2026
What the research looked at
Each line is one body of research, graded A (strong) to D (weak). How we grade evidence. What each study measured is explained in your personal plan.
| Grade | Who was studied | References |
|---|---|---|
| C | Adults with low mood |
|
How much
- Our plans usually use 100 mg a day for adults. The exact dose depends on your lab results, age and medicines.
- Adult upper limit: 300 mg a day from food and supplements together. Source: Trials used 50-300 mg a day (Javelle F et al. Nutr Rev 2020).
- Children's doses are set by age, and some ingredients are for adults only.
Who should not take it, or should check first
- Not suitable. No safety data in pregnancy or lactation.
- A clinician checks first. Serotonergic precursor; always clinician-reviewed.
- Not suitable. Serotonergic agents can trigger mania.
Medicines and other supplements
- Not suitable. Serotonin syndrome risk with antidepressants, MAO-B inhibitors, levodopa, linezolid, methylene blue, dextromethorphan, triptans, tramadol, pethidine, fentanyl, methadone, tapentadol, buspirone and lithium.
- A clinician checks first. Two serotonergic ingredients together.
Your plan is checked against every medicine you tell us about. If you take a medicine, ask your pharmacist or doctor before starting a new supplement.
Where we sell it
- Not sold in Australia, the UAE, Saudi Arabia, Lebanon.
Written and reviewed by the Atrum Labs clinical team (physician-scientists, MD, PhD) from our clinical knowledge base, version 0.2.0-draft. This page is general information, not medical advice. Food supplements are not a substitute for a varied, balanced diet and a healthy lifestyle.
See if it belongs in your plan