Glycine
Glycine is the smallest and simplest amino acid, found abundantly in collagen-rich foods like bone broth, skin, and connective tissue. It serves as a building block for proteins, a precursor to the antioxidant glutathione, and an inhibitory neurotransmitter in the brainstem and spinal cord. It has gained particular attention for its ability to promote restful sleep without disrupting normal sleep architecture.
Research Evidence
Does not disrupt normal sleep architecture or staging
ModerateImproves subjective sleep quality and next-day alertness
StrongMay improve cognitive performance following sleep
LimitedSupports glutathione production and antioxidant defense
ModerateLowers core body temperature to facilitate sleep onset
ModerateReduces time to fall asleep and reach deep sleep stages
ModerateExpert Evidence
31 references from 3 experts
Safety & Cautions
Side Effects
- Mild nausea at high doses
- Soft stools
- Rare reports of drowsiness during daytime use
Glycine is generally very well tolerated, even at doses of 3 grams or more daily. Those taking antipsychotic medications like clozapine should consult a healthcare provider, as glycine may interact with these drugs.
Pairs Well With
Price Comparison
From $0.06/ct
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4.5
•360 ct$0.06/ct
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P Puregen Labs
4.6
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4.6
•100 ct$0.09/ct
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Life Extension
4.6
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T
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4.7
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P
Pure Encapsulations
4.7
•180 ct$0.19/ct
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