Decreased antioxidant capacity and increased oxidative stress have been observed in fibromyalgia patients. Some trials have also shown that CoQ10 levels are reduced in these patients but that supplementation can restore levels and reduce fibromyalgia symptoms, including pain and fatigue. We evaluated the effect of administration of a finished form of CoQ10 (DDM Chinone®) at a dose of 200 mg×2/day in 22 female subjects with a diagnosis of fibromyalgia in a randomized, open-label, cross-over study. Our results show that, compared to a control group, administration of CoQ10 significantly improved most pain-related outcomes by 24-37%, including fatigue (by ~22%) and sleep disturbance (by ~33%). These results confirm the considerable role played by CoQ10 in reducing pain, fatigue, and sleep disturbance in subjects affected by fibromyalgia.