Glycine and its sodium salt

Studies in people

• Benefit

  Aging and physical function²

  In older adults, taking glycine with NAC improved walking speed, strength and other signs of aging.

• Benefit

  Aging and muscle strength³

  In eight older adults, 24 weeks of glycine plus NAC improved strength, walking speed and thinking, but benefits faded after stopping.

• Benefit

  Obesity and liver health⁴

  People with obesity and fatty liver often have low glycine levels, and glycine supplements may help.

• Benefit

  Liver health in obesity⁵

  In people with severe obesity, two weeks of glycine supplements lowered blood fats and liver enzyme levels.

• Benefit

  Blood pressure and cholesterol⁶

  People who ate more glycine tended to have lower rates of high blood pressure and high cholesterol.

Animal and lab studies only

• Open question

  Body's antioxidant defenses⁹

  In animal studies, glycine raised glutathione, but scientists do not yet know whether it does the same in people.

• Benefit

  Immune system and inflammation¹⁰

  In animal studies, glycine calmed immune cells and protected the liver and kidneys from injury.

• Concern

  Blood clotting¹¹

  In animal studies, glycine made blood take longer to clot and slowed platelets clumping together.

Study type not stated

• Open question

  Muscle strength and recovery⁸

  Glycine may help muscle strength and recovery, but scientists do not yet know if it truly works in people.

How it’s made and used

• Pregnancy nutrition needs⁷

  Pregnant women in late pregnancy may need more glycine than they get from food.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least one finding in people. When most findings in people point one way, the page leans that way (“Mostly”), and every finding is still shown. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.