Epsom Salts is the go-to. I have M.E. and have a friend with M.E. and Fibromyalgia and we both swear by it. What you have to watch out for is quantity, water temp and duration in the bath. A large handful, in warm-hot (not boiling) water and for twenty minutes seems to be about right. There is a company that has latched on to Epsom Salts and is now producing trendy varieties with trendy names like Mindfulness. Avoid these or anything added which will dilute the purpose of the Epsom Salts and potentially trigger VA issues. So, these are medicinal baths with only Epsom Salts, no having a wash with soap etc at the same time. Also, pat dry to allow the transdermal effect, no rubbing dry. I sometimes just sit in a bath sheet letting it all soak in. Good luck!