New therapeutic strategy for amino acid medicine: glycine improves the quality of sleep

Researchers gave a small group of healthy adults 3 grams of glycine, an amino acid found in foods and made by the body, before bed. On other nights, they received a placebo, an inactive treatment used for comparison. Participants reported better sleep quality and felt less tired the next day after taking glycine. The study was small and short, and it did not test people with diagnosed sleep disorders.

What this means for you: Glycine may modestly help some healthy adults sleep better, but this is not strong enough evidence to recommend buying it. It should not be viewed as a proven treatment for insomnia.