Niacin, also known as nicotinic acid or vitamin B3, is a water-soluble vitamin discovered by Conrad Elvehjem in 1937. Its derivatives, NADH, NAD, NAD+, and NADP play essential roles in energy metabolism in the living cell and DNA repair (an enzymatic process in a living cell). The designation vitamin B3 also includes the corresponding amide nicotinamide (or "niacinamide"), whose chemical formula is C6H6N2O. Other functions of niacin include removing toxic chemicals from the body, and assisting in the production of steroid hormones made by the adrenal gland, such as sex hormones and stress-related hormones.