Glycocyamineis a metabolite of glycine in which the amino group has been converted into a guanidine. Glycocyamine is a direct precursor of creatine and is used as a supplement. However the metabolism of creatine from glycocyamine in the liver causes a depletion of methyl groups. This causes homocysteine levels to rise, which has been shown to produce cardiovascular and skeletal problems. A series of studies showed that a combination of betaine and glycocyamine improves the symptoms of patients with chronic illness, including heart disease, without toxicity. Betaine can provide a methyl group to glycocyamine, via methionine, for the formation of creatine. In overal, such treatment led to less fatigue, greater strength and endurance, and an improved sense of well-being. The patients with cardiac decompensation and congestive heart failure had improved cardiac function.