Generally, glutathione is used for treating certain health conditions; however, it is also known as an effective skin lightener. Glutathione contains cysteine, an amino acid that has been proven to lighten skin color in sun-exposed skin. You can boost your glutathione levels by eating glutathione-rich foods, such as avocados, spinach, melons, squash, asparagus, and potatoes – just to name a few. You can also increase your glutathione levels by taking effective glutathione capsules, such as Reijin Glutathione.