Glycine

Glycine is an amino acid that your body makes and that food also provides. In addition, its most concrete interest here concerns sleep: a few small trials suggest an improvement in certain measures of sleep quality or fatigue the next day. The evidence remains limited; it deserves a secondary place after regular schedules and sufficient sleep time.

Sleep trials have notably used 3 g before bed, but this amount is neither an additional daily requirement nor a demonstrated optimal dose. If you are considering a trial, follow the product instructions and evaluate a specific objective. Glycine alone has not been shown to visibly improve skin, erase wrinkles, or replace a diet sufficiently rich in protein.