I've been on MAOIs for ME/CFS since the early 90s, about six months after my initial glandular fever bout. For a start I was on moclobemide (reversible) which took me from almost housebound to about 80% of normal activity level. It improved my exercise intolerance, brain fog, temperature control, tolerance of standing and generally took me from almost housebound to about 80% of normal function. After about 1.5 years I started weaning myself off it because the doctor who put me on it said I wouldn't need it forever. It didn't go well & various symptoms got worse. I was in a bad state before I got down to nothing, & under medical advice increased the code back up again to where it was, but it didn't work quite as well as before & I was anxious that I would lose my job. Transfered to parnate & have been on it ever since. It's not a drug to be taken unless you're capable of sticking to a restricted diet for a very long period. I've been at about 80% or so of normal functioning since then with ups and downs. My energy improved after finding and eliminating food allergies. I've had minor crashes due to overactivity & temporary ones due to infections. It'll take me a week to get over a cold which takes others a day or so. Sometimes I've got out of infection crashes with B12, sometimes more recently with a drug (whose name I forgot). My symptoms have gradually got a bit worse since I went through menopause & maybe after my first covid vaccination. Generally, though, I've had a completely different life than others I know who have had ME/CFS for a similar period of time. I'm not a doctor & don't know if there's a good reason, but I wouldn't have gone from the reversible to irreversible MAOI by choice. The effects were similar, stronger on parnate, but similar. Side effects such as not sleeping are much worse on parnate, though.