A study performed in April 2012 and published in the Journal of Dermatological Treatment found that oral glutathione decreased the amount of melatonin in the skin of the test subjects, thereby lightening skin tone. It is also used to lighten sun spots, age spots, freckles and other blemishes.
Glutathione skin whitening pills work by preventing the oxidation of melanin in the skin, helping to shed cells that already contain melanin, and reducing the production of pigmentation in the skin, according to Princeton Nutritional Systems, the manufacturers of Ivory Caps. The company claims that the supplement creates a more balanced, even lightening effect than bleaching creams, due to the fact that it works first on the inner layers of the skin, the dermis, and enacts change slowly in the outer layers, the epidermis. The change is gradual, occurring over a period of weeks or months, so it is not immediately apparent to others that a supplement is being used to alter skin tone.
ImmuneHealthScience.com lists the recommended dose of glutathione as 500 to 1000 milligrams per day, but also notes that higher doses, up to 3000 milligrams per day, are generally well-tolerated and do not produce negative side effects. Results vary from one individual to the next, with reports of noticeable changes anywhere from one month to one year after the daily oral regimen begins.