America's Compounding Center says the following about Ribose:
"Ribose is a sugar that is produced by the body from food as a source of energy. Ribose may be effective at increasing energy levels, improving ath;etic performance, improving functionality in patients with coronary artery disease, fibromyalgia, and congestive heart failure, and to prevent symptoms associated with the mitochondrial disease moadenylate deaminase (MAD) deficiency (also known as AMPD deficiency) after exercise, such as muscle pain and cramping. Ribose is usually given as a 15g oral dose four times daily, but can also be given before, during, and after exercise to prevent muscle cramping. Side effects of ribose include stomach discomfort, nausea, diarrhea, headache, and hypoglycemia."