Most of the glycine in the body becomes incorporated in proteins, but free glycine acts as a neurotransmitter involved in regulating appetite, behavior and general homeostasis.² It has fundamental roles in support of healthy gene expression, cellular antioxidant processes, detoxification, immune function, growth, development, metabolism and survival.² Like other one-carbon molecules, glycine has been linked to longevity in certain species.^3,4

Glycine is often used as a supplement to promote relaxation and sound sleep. Research shows that, when taken before bed, glycine may promote healthy quality sleep without causing daytime drowsiness.^5,6 Glycine may also have positive impacts on mood, cognition and mental health.^7,8

Glycine is needed for collagen production and therefore supports connective tissue throughout the body.^9,10 Glycine has been shown to preserve normal muscle mass and promote healthy body composition.^11,12 Importantly, it is the rate-limiting component of the major antioxidant glutathione.^13,14

Glycine has been demonstrated to inhibit protein glycation and production of advanced glycation end-products (AGEs).¹³ Evidence from laboratory and clinical trials suggests glycine may help support healthy glucose and fructose metabolism.^13,15,16 Research shows glycine may help maintain normal blood pressure.^14,17 A study that included more than 4,000 subjects found higher glycine levels were correlated with cardiovascular protection and better metabolic health.¹⁸ Glycine has been shown to support health of the gastric and intestinal lining.^19-21 

In addition to its many and varied benefits, glycine has a strong safety record. Most people need to take between one to three grams of glycine to experience benefits. As a result, using low dose capsules can be cumbersome and expensive. Life Extension’s glycine comes in easy-to-swallow 1000-mg capsules.