L-cysteine

Studies in people

• Benefit

  Hangover symptoms²

  In a study of men, L-cysteine seemed to prevent or ease hangover, nausea, headache, stress and anxiety.

• Benefit

  Memory and brain aging³

  In people, l-cysteine with vitamin D may help mild memory problems, but scientists do not yet know for sure.

• Benefit

  DNA damage after exercise⁴

  In basketball players, one month of l-cysteine may reduce DNA damage from training.

Animal and lab studies only

• Benefit

  Blood sugar control⁵

  In animal studies, L-cysteine improved how the body handles sugar, but scientists do not yet know whether it helps people with diabetes.

• Benefit

  Vitamin D absorption⁶

  In lab and animal studies, l-cysteine helped the body turn vitamin D into the form it uses.

• Benefit

  Blood vessel health in diabetes⁷

  L-cysteine reduced blood vessel cell stickiness caused by high sugar and ketones.

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.