GAA increases skeletal muscle creatine in men
Guanidinoacetic acid (GAA; also known as glycocyamine,betacyamine, or guanidinoacetate) is an experimental dietaryadditive that enhances serum creatine bioavailability and affectsblood-derived metabolic markers of methylation in humans. Because creatine is an important compound in cellular bioener-getics, consumption of GAA has been recognized as an effec-tive investigational intervention to facilitate creatine-mediatedenergy provision in health and disease. At the same time,the methylation of GAA to form creatine consumesw40% ofavailable methyl groups, potentially depleting the sources ofmethyl groups in the body, including methionine, folate, betaine,and choline. However, to our knowledge, no human study sofar has evaluated the effects of GAA consumption on creatinebioavailability and/or use of methyl groups in tissues withhigh-energy requirements, such as skeletal muscle or brain. Inthis pilot study, we evaluated the effects of 4-wk GAA supple-mentation on total creatine and choline levels in human skeletalmuscle of healthy men [TRUNCATED].
Ostojic SM, Drid P, Ostojic J. Guanidinoacetic acid increases skeletal muscle creatine stores in healthy men. Nutrition. 2016 Jun;32(6):723-4. doi: 10.1016/j.nut.2015.11.006. Epub 2015 Dec 18. PMID: 27126958.