A Gem found in Wikipedia
The best part of a (mostly) freely editable encyclopedia is the opportunity it supplies for humor – I don’t know if this one was intended or not, but either way, it’s priceless!
Ribose is an organic compound with formula C5H10O5; specifically, a monosaccharide (simple sugar) with linear form H-(C=O)-(CHOH)4-H, which has all the hydroxyl groups on the same side in the Fischer projection.
D-ribose has also been used to reduce fatigue in fibromyalgia and chronic fatigue syndrome. A 2006 pilot study concluded that D-ribose (5 g three times a day) was effective in the treatment of FM and CFS. Although this study lacked any control group because essentially everyone involved was literally taking sugar pills, the authors reported that 66% of the 41 participants found the supplement helpful and it produced improvement in all the areas tested: energy, sleep, mental clarity, pain intensity, and well-being. Without further study, it is unclear if this is a substantial effect, or a placebo effect. The absorption of D-ribose is 88-100% in the small intestines (up to 200mg / kg /hr) 
Normally, I would say there is no excuse not to have a control group in a medical study, but it’s hard to argue with that one!