Glycine
- Effective dose
- 3–3 g
- Evidence
- 2/5· Emerging
Last updated June 1, 2026
What it is
Glycine is the simplest amino acid and a building block for glutathione, creatine, and collagen. For sleep it is thought to act on sleep-regulating neurons and promote peripheral vasodilation, which lowers core body temperature near bedtime.
Benefits
Taken before bed, glycine can improve subjective sleep quality, shorten sleep onset, and reduce next-day sleepiness; the studied dose is 3 g about 30 minutes before sleep.
When to take it
Taken about 30 minutes before bedtime for sleep; can be dissolved in water.
Side effects
Well tolerated at typical doses, with occasional mild GI upset; doses far above the studied range have not been confirmed safe and very high intakes may stress the kidneys and liver. People with kidney disease should consult a clinician.
Sources
Products containing Glycine
No products in our database contain this ingredient yet.