Glutathione is typically not well absorbed by the body when taken orally, so it is administered intravenously, according to WebMD. The dosage is determined by a doctor. However, Science-Based Medicine advises that, as of 2015, there is no proof that glutathione is safe or effective as a skin whitening agent.
Glutathione is an antioxidant that naturally occurs in the body, explains WebMD. Doctors use it primarily to treat the side effects of chemotherapy. Glutathione is typically recommended for the purposes of skin whitening in the homeopathic community, but it is not used in this way by medical professionals. Consulting with a medical professional is advisable before attempting to determine the dosage of glutathione appropriate for the purpose of skin whitening.