What does Glutathione do? Benefits and evidence

Glutathione is an antioxidant your cells make from three amino acids. Oral studies sometimes raise glutathione levels, but clear health benefits are less certain. Small skin studies show modest or temporary changes. Systemic injections have no FDA-approved wellness or skin-lightening use. Compounded IV products have caused serious reactions, including a new FDA warning in August 2026.

• In a trial, taking it by mouth for longer raised the body's glutathione stores; preventing disease was not shown. (Studied in a trial)
• In small studies, taking it by mouth or on the skin lightened skin tone a little, and the effect was often temporary. (Studied in a trial)
• In older small trials, it reduced nerve damage from some chemotherapy, but a larger phase 3 trial found no such benefit. (Studied in a trial)
• Some users report brighter or clearer skin, from injections or from pills taken with NAC and vitamin C. (Reported by users)

Uses in the sources

• Studied for skin tone and melasma. Oral and topical effects are modest; IV cosmetic evidence is weak. (Studied in a trial) (source)
• Oral studies measure antioxidant stores. Longer life or prevention of age-related disease has not been demonstrated. (Studied in a trial) (source)
• Studied in Parkinson disease, cystic fibrosis, diabetes and fatty liver. Results differ by disease and route. (Studied in a trial) (source)
• Studied to reduce chemotherapy nerve damage. Older small trials were positive; N08CA phase 3 was negative. (Studied in a trial) (source)
• Small exercise trials examined fatigue or citrulline combinations. Durable performance or muscle benefits remain unproven. (Studied in a trial) (source)
• Posted CF registry results agree that the later trial found no growth benefit; the earlier small trial was positive. (Studied in a trial) (source)