Glutathione is an important antioxidant your body produces. In the body, glutathione neutralizes unstable atoms known as free radicals, to prevent them from damaging cells. Glutathione is also available as a dietary supplement. It's marketed for antioxidant and anti-aging benefits. However, data showing any benefit from oral glutathione is lacking. The safety of glutathione has not been adequately researched, but one study reported mild side effects.
Reported Glutathione Side Effects
A study in the September 2011 issue of the "Journal of Alternative and Complementary Medicine" describes mild side effects related to glutathione supplementation. There were no serious side effects but some participants experienced loose stools, flatulence, weight gain and flushing. The dose used in the study was 500 milligrams twice daily for four weeks. A recommended dose has not been established. Take glutathione only as directed by the supplement manufacturer, or your doctor.