The best 3 brown spots treatment ingredients available over the counter are Arbutin, Kojic Acid, and Licorice.
Arbutin is a natural derivative of hydroquinone derived from plants, including bearberry, blueberry, and cranberry. Some cosmetic products contain 3% concentrations, which studies show can significantly lighten the skin.
Kojic Acid is an antioxidant derived from a fungus. It works by breaking down melanin in the skin and preventing its production in the skin. Kojic Acid is found in cosmeceuticals in 1% to 4% concentrations either combined with other skin-lightening agents or by itself.
Licorice: Is the source for a number of different licorice extracts derived from licorice root. Liquirtin is available over the counter and has been shown to lighten skin.