Ribose was added to the existing treatment regimen of a woman with fibromyalgia, resulting in a decrease in symptoms. It has been postulated that patients with fibromyalgia may have an alteration in muscle adenine nucleotide metabolism, leading to depleted energy reserves and an imbalance in cellular adenosine 5'-triphosphate:adenosine 5'-diphosphate:adenosine 5'-monophosphate (ATP:ADP:AMP) ratios with an abnormal energy charge. As a key component in adenine nucleotide synthesis, ribose supplementation may be useful in such patients.