NOTE: our listing is 750mg for each capsule. (capsule size "00") 100% D-Ribose (No Rice Powder or any other fillers added) there are listings from other sellers indicating 1200mg per serving Ribose. this is a very deceptive practice meant to suggest each capsule is 1200mg, when in fact you have to take 3 capsules to get 1200mg. so each capsule is only 400mg !! D-Ribose is a kind of sugar that is produced by the body. It is used as a medicine. Ribose is used to improve athletic performance and the ability to exercise by boosting muscle energy.