Mestinon

Mestinon (Pyridostigmine) is an aceytlcholinesterase inhibitor used to treat myasthenia gravis and Sjögren's syndrome. It inhibits the acetylcholinesterase enzyme from breaking down acetylcholine, resulting in higher circulating levels of the neurotransmitter. It cannot cross the blood brain barrier, and so only works on the peripheral nervous system.

Anecdotally, some ME/CFS patients have derived huge benefits from Mestinon, others none at all. A work in progress study of exercise intolerance in preload failure found that Mestinon improved exercise tolerance, but the study has not yet been published.

Learn more

 * "Mestinon for ME", Living With Chronic Fatigue Syndrome blog post, September 13, 2017
 * "A Mestinon Miracle: Vagus Nerve Stimulating Drug Helps Long Time ME/CFS Patient Exercise", Health Rising Blog, June 17, 2016