Check before you startThis one has documented interactions with medication classes where the consequences are serious. If you take any prescription medicine, run it past a pharmacist before starting.
How long to take it
Short courses — days for jet lag, weeks for a shifted schedule. Not a nightly permanent aid without medical advice.
Who it's actually for
Jet lag, shift work, and delayed sleep phase. Less useful for classic insomnia.
Safe upper limit
UnverifiedNo formal limit; 0.5–3 mg is effective, and more is not better
Higher doses cause grogginess and vivid dreams without improving sleep. Long-term effects in children are not well established. Regulated as a supplement in North America but a prescription drug in the UK/EU — itself worth surfacing. No IOM-style UL exists; needs a clinical pharmacology source, not a nutrient fact sheet.
No source attached yet. Treat this as a starting point, not a citation, until reviewed.
Interactions to know about
- Blood thinners / antiplatelets — Warfarin, apixaban, rivaroxaban, clopidogrel, aspirin
- Sedatives / sleep medication — Benzodiazepines, zopiclone, zolpidem, opioids
- Diabetes medication — Metformin, insulin, gliclazide, SGLT2 inhibitors
- Immunosuppressants — Ciclosporin, tacrolimus, azathioprine, biologics, steroids
- Anti-seizure medication — Phenytoin, valproate, carbamazepine, lamotrigine
Other supplements:
Run your full list through the interaction check.
Practical notes
- Take it two to three hours before your target bedtime, not at bedtime.
- Start at 0.5 mg — most products are five to ten times stronger than needed.
- Talk to a paediatrician before giving it to a child.