Glycine
Commonly used for
SleepHealthy AgingAthletic Performance
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What is it? / Overview
Glycine is an amino acid involved in collagen production and acts as an inhibitory neurotransmitter in the brain. Taken before bed it may modestly improve sleep quality and next-day alertness.
How is it used? / Administration
Form: Pure glycine powder
Typical dose studied: 3–5 g/day; 3 g before bedtime for sleep support
Timing: 30–60 minutes before bed for sleep benefit
Sweet-tasting powder that mixes easily in water. Pairs well with collagen supplementation.
How well does it work? / Evidence
~ Moderate evidence
Who should avoid it?
Interacts with: Use caution with sedatives
Already taking it? Monitor for excessive drowsiness.
Research & references
Bannai M et al. (2012). The effects of glycine on subjective daytime performance in partially sleep-restricted healthy volunteers. Front Neurol. Yamadera W et al. (2007). Glycine ingestion improves subjective sleep quality in human volunteers, correlating with polysomnographic changes. Sleep and Biological Rhythms.
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