The case studies below demonstrated that pyridostigmine to be beneficial in chronic fatigue syndrome and fibromyalgia. While this was case reports of only 3 patients, I have also found pyridostigmine to be helpful in fatigue in weakness in some patients. It does seem to be more helpful in patients that are positive for EBV. This is an indication that this virus may somehow block or inhibit the acetylcholine function at the neuromuscular junction in some patients, resulting muscle weakness and fatigue.

Efficacy of a half dose of oral pyridostigmine in the treatment of chronic fatigue syndrome: three case reports.