Glycine for Sleep Dosage: How Much & How Often
3 g by mouth about 60 minutes before bed — the dose used in the published sleep trials.
Evidence-based answer
Sleep studies of glycine used 3 grams taken about an hour before bed. In small trials this dose was associated with people falling asleep faster and reporting better sleep quality and less daytime fatigue. Glycine is a naturally occurring amino acid; 3 g is the dose with the most direct evidence.
Reviewed by Chad Waldman, Analytical Chemist · Last reviewed 2026-07-15
Dose by goal
| Goal | Dose | Frequency | Evidence |
|---|---|---|---|
| Sleep quality / onset | 3 g | ~1 hour before bed | moderate |
| Higher doses | Beyond 3 g not better-studied for sleep | n/a | limited |
What the evidence shows
- Glycine research reports that 3 g before bed improved subjective sleep quality and shortened the time to fall asleep (PMID 22293292).
- A study measured reduced daytime sleepiness and improved performance after 3 g glycine before bed in partially sleep-restricted volunteers (PMID 22529837).
What it does not show
- Trials are small and short; long-term effects are not established.
- Evidence does not support glycine as a treatment for diagnosed insomnia or sleep disorders.
Safety & cautions
- Generally well tolerated; mild GI upset is possible.
- Discuss with a clinician if you take sedatives or clozapine or have kidney disease.
- Not a treatment for any sleep disorder.
Research citations
- Bannai M, Kawai N (2012). New therapeutic strategy for amino acid medicine: glycine improves the quality of sleep. Journal of Pharmacological Sciences. PMID 22293292Reviews evidence that 3 g glycine before bed improved subjective sleep quality and shortened time to fall asleep.
- Bannai M, Kawai N, Ono K, Nakahara K, Murakami N (2012). The effects of glycine on subjective daytime performance in partially sleep-restricted healthy volunteers. Frontiers in Neurology. PMID 225298373 g glycine before bed was associated with reduced daytime fatigue and better performance after sleep restriction.
Educational information only — not medical advice. Talk to a licensed clinician before starting any protocol.