Key Takeaway
3g glycine before bed improved subjective sleep quality and reduced daytime sleepiness in people with sleep complaints.
Summary
This placebo-controlled crossover study examined the effects of glycine on sleep quality in volunteers who had been continuously unsatisfied with their sleep. Participants received 3g glycine or placebo before bed.
Glycine significantly improved subjective sleep quality, sleep efficacy, and reduced daytime sleepiness. Polysomnographic analysis showed glycine shortened latency to sleep onset.