Inosine is an important chemical found throughout the body. It plays many roles, one of which is helping to make ATP (adenosine triphosphate), the body's main form of usable energy. Based primarily on this fact, inosine supplements have been proposed as an energy-booster for athletes, as well as a treatment for various heart conditions.

Inosine is not an essential nutrient. However, brewer’s yeast and organ meats, such as liver and kidney, contain considerable amounts. Inosine is also available in purified form.