L-Glycine, or glycine, is a non-essential amino acid, which means your body can produce it on its own if not enough glycine is available through your diet. Glycine is the smallest amino acid in size, but it has many powerful effects on your body and is involved in a variety of biochemical reactions. Glycine is found naturally in animal products, including meat, fish, poultry, and dairy, but can also be ingested as a nutritional supplement. Because glycine is naturally produced by your body, it has very low toxicity, and any excess glycine that you eat will be excreted in your urine. Ask your doctor about glycine before using it as a nutritional supplement to make sure it is right for you.
Glycine is important for the construction of healthy DNA and RNA strands, which are the genetic building blocks that are necessary for the proper function of your body's cells. Glycine is one of the three amino acids that forms creatine, which can help to promote muscle growth and energy production during exercise. Glycine is also the primary component of collagen, the non-contractile connective tissue that makes up most of your skin, tendons, and ligaments.
Glycine acts as a glucogenic amino acid, meaning it can help your body regulate blood sugar levels and provide glucose to various body tissues for energy. Glucogenic amino acids control the amount of blood sugar that is released into your bloodstream from your liver and fat stores, and regulates the amount of glucose that is taken up by your skeletal muscles to be used for energy. As a result, glycine supplementation may benefit people suffering from hypoglycemia, or low blood sugar, anemia, and chronic fatigue.
Your digestive system relies on glycine in order to function normally. Glycine is found in high concentrations in your gallbladder and assists in the production of bile, which is a substance used to digest dietary fatty acids. Glycine is a common ingredient in antacids because of its ability to balance the acid-base ratio in your digestive tract, according to a 2006 study published in the "Journal of Pharmaceutical Sciences."
According to the book, "Anabolic Primer," glycine is best known for its effects on your nervous system. Glycine affects the production of brain neurotransmitters, which are essential for maintaining normal brain function and emotions. Glycine supplementation may also help treat symptoms associated with sleep deprivation. In a 2007 study published in the journal "Sleep and Biological Rhythms," investigators found that glycine supplementation improved both subjective and objective measures of sleep quality in patients who experienced continuously unsatisfactory sleep.