Glutathione is a powerful ingredient, but not all products contain meaningful or functional amounts. I recently looked into a popular glutathione serum and found unclear claims ranging from 50,000 ppm to 500 ppm—an enormous difference. In reality, even 500 ppm in a 50 ml bottle equals only about 25 mg, which is far below what many true glutathione supplements deliver per dose. Most cosmetics also use oxidized glutathione, which isn’t the active form your body needs. Always check labels carefully and look for products using reduced glutathione in effective amounts.