I do have a co-Dx of CIRS, so this may not apply to all here. I have had several terrible exposures to mold, which is a known symptom-exacerbator for me. It's early days, as I've only been taking it for ten days, but the initial response is so positive! I had three days of feeling Wow! and then three days of feeling like there was a strong viral reactivation (fluey, burning skin, burning spine, headache, IBS-D etc.) By yesterday I felt so much better that I waaaay overdid, and so today am in full PEM. Besides the foolish housecleaning bonanza I went on yesterday, I have been otherwise sticking to resting and pacing; but the urge to use some of the wave of new-found energy was too strong to resist. I haven't felt like that for ages. So it doesn't appear to address whatever causes PEM, but it does bring a big uptick in natural non-jittery energy, brain function etc. In reading about all its mechanisms of action, it does seem like a perfect Tx for me. I have been wanting to try VIP for many years, on the advice of one of my doctors, but she warned there was no point at all while I was still living in a moldy environment, as it wouldn't work. It has taken me years --YEARS--to find suitable housing and get myself to it. Everything is so much harder with M.E. I am really hoping this is a game-changer for me, as I have been deteriorating these last few years in a scary way. Even if it's not a panacea, addressing a chunk of what's wrong is a welcome thing. Are others taking it, or have tried it? Share your experience here, I'd love to hear. https://www.sciencedirect.com/topics/neuroscience/vasoactive-intestinal-peptide