5-HTP

5-hydroxytryptophan, oxitriptan, L-5-hydroxytryptophan

Sold freely in United States and restricted in European Union. Same substance, same evidence, different decisions.

A serotonin precursor sold for mood and sleep.

5-HTP is sold over the counter as a dietary supplement across the United States, while in parts of Europe the same molecule (oxitriptan) is a licensed prescription medicine. Member-state treatment diverges: Italy authorizes it as a prescription drug for post-anoxic myoclonus, whereas France, the Netherlands and the United Kingdom permit it as a food supplement. Caution around tryptophan-pathway products traces partly to the 1989 L-tryptophan eosinophilia-myalgia syndrome outbreak, linked to a contaminated manufacturing batch, and to a later contaminant ("Peak X") that FDA-informed investigators detected in commercial 5-HTP.

Where it stands, jurisdiction by jurisdiction

United States
Open, sold freely
Sold over the counter as a dietary supplement under the Dietary Supplement Health and Education Act of 1994. The FDA does not approve dietary supplements before marketing; manufacturers are responsible for safety, and the FDA acts after market if a product is found unsafe. There is no FDA-approved drug product containing 5-HTP. A historical concern, distinct from the 1989 L-tryptophan eosinophilia-myalgia syndrome episode, involved a contaminant called Peak X that FDA-informed Mayo Clinic researchers detected in commercial 5-HTP in the late 1990s.
- US FDA, Questions and Answers on Dietary Supplements
- Peer-reviewed record of FDA-informed Peak X detection in commercial 5-HTP (PubMed)
European Union
Restricted, restricted
Status varies by member state. In Italy the molecule (oxitriptan, L-5-hydroxytryptophan) is an AIFA-authorized prescription medicine, marketed as Tript-OH for post-anoxic myoclonus, dispensed only against a medical prescription. In France, the Netherlands and other states it is permitted as a food supplement. The EU has no single harmonized ruling for 5-HTP, so treatment ranges from prescription medicine to over-the-counter supplement depending on the country.
- AIFA / Italian authorized product Tript-OH (oxitriptano), post-anoxic myoclonus, prescription medicine
- Italian Medicines Agency (AIFA), medicinal product supply regime

Regulatory positions change, sometimes quickly. Check the date on a source before relying on it.