Glycine (through the consumption of collagen) significantly improved skin elasticity in elderly women and improved skin moisture and water loss [4, 5].Collagen peptide, which contains a lot of glycine, suppressed UV-B induced skin damage and photoaging [6].Women taking 2.5g of collagen peptide for 4 weeks significantly reduced eye wrinkles by 20%, with positive effects lasting after the study ended [7].At 8 weeks, collagen significantly improved skin content of procollagen type I by 65%, and elastin by 18%.

Glycine nearly doubles the speed at which skin ulcers heal in 89 diabetic patients across 23 long term care facilities [8].Glycine enhanced wound healing in diabetic animal models as well [9].Glycine in combination with l-cysteine and dl-threonine topically applied to leg ulcerations significantly improved the degree of wound healing and decreased pain [10].

In ischemic stroke patients, taking glycine 1 – 2g/day normalized autoantibodies, reduced glutamate and aspartate levels, increased GABA concentrations, and reduces lipid peroxidation [21].Those who consume regularly low doses of glycine actually reduce damage in future strokes [21].The glycine treatment at the dose of 1 – 2g/day was accompanied by a tendency to a decreased risk of dying over 30-days [21].

Glycine prevents lactate dehydrogenase leakage (a cell death indicator) in rat liver cells in test tubes [53].In rats with alcohol poisoning, feeding glycine reduced accumulation of cholesterol, phospholipids, free fatty acids and triglycerides in blood circulation, liver, and brain, ultimately reversing liver disorder associated with fat accumulation [19].

Glycine supplementation may prove useful for diabetic ulcers, schizophrenia, and stroke recovery. Other human studies suggest a potential benefit for other areas of metabolic and mental health, including insulin resistance, insomnia, and sleep disorders.