I take coffee adrenals & am hypothyroid & hypoadrenal. They always make me feel better and I never have any negative side effects. Ever. (That is, except for one time when I went beyond 2 cups. As Gerson says, if they go too high they will have the effect of coffee that one drinks.)
There is the theoretical approach, and then there is the actual experimental approach. I prefer the latter as long as I know there can be no real harm.
My doctor - very friendly to alternative health methods - said he used to work with a doctor who gave coffee enemas (tho my doctor was not trying to talk me into doing any or avoiding them) and he said, "He cured a lot more cancer patients than I did with my methods."
I know him. I know how coffee enemas make me feel. I know what the research says. I will continue on with them periodically and hope others discover their benefits also.
:-)