Glycine
Simplest amino acid, always given as 3 grams before bed in sleep research.
What the research shows
Mixed or small evidence. The effect is uncertain.
Soh (2024) judged the sleep studies in healthy people to be small and at high risk of bias, and called for larger research. Bannai (2012) saw better subjective scores under artificially shortened sleep, in a study whose authors all worked for amino acid producer Ajinomoto. The proposed mechanism, a drop in core temperature, comes from rat experiments.
Who it makes sense for: People with mild trouble falling asleep who want to try 3 grams and know the evidence comes from the manufacturer.
How we weigh evidenceClinical dosage
Scientific sources
The clinical dosages on this page are based on peer-reviewed research.
- The effect of glycine administration on the characteristics of physiological systems in human adults: A systematic review.Soh J et al. (2024)
- The effects of glycine on subjective daytime performance in partially sleep-restricted healthy volunteers.Bannai M et al. (2012)Funded by: Alle auteurs waren verbonden aan Ajinomoto Co., Inc., producent van aminozuren.
- New therapeutic strategy for amino acid medicine: glycine improves the quality of sleep.Bannai M et al. (2012)Funded by: Beide auteurs waren verbonden aan Ajinomoto Co., Inc., producent van aminozuren.
We keep the dosages and values on this page as accurate as possible based on selected studies. New research may change these values. Nothing on this page is medical advice. If you have any doubts, always consult a doctor.