“Poison” is a relative term. Chemotherapeutic agents are poisonous as hell: that is the point. So the fact that Essiac is toxic doesn’t necessarily argue against its anti-cancer properties. Plenty of medicines have come from traditional sources. Now, the studies using animal models that have been done suggest that, at best, it may slow the progression of some types of cancer (prostate) but not others (leukemia, sarcomas/epithelial cancers, and so on). That would incline me to suggest against using it, unless you have prostate cancer and no hope for treatment. Even then, I probably wouldn’t. A lot of people want to avoid treating prostate cancer because of the negative side effects, so I could see people opting for the snake oil over the real treatment.
In cases where modern medicine has failed, hey man, any port in a storm. I’m not gonna say ‘no’ to the people who want to use any means they can find to treat their illness. But at the same time, chasing shadows usually isn’t a good idea. A family friend died because she tried some hippy-dippy treatment instead of real treatment. If it sounds too good to be true, it probably is.
In Cyrene’s case, I’m also not sure why recommend it. While I can’t comment on his condition, a lot of chronic pain sufferers tend to have an autoimmune disorder. Even if Essiac works as advertised, stimulating the immune system would be the last thing you’d want to do! Additionally, the problem detailed in the OP is a problem with feeding. Since Essiac causes nausea, I don’t imagine that would much stimulate the appetite.
There are, however, herbs that have been shown to stimulate the appetite (surprise! Marijuana is one of them. But there are others, though they are probably less effective. Check out some anorexia groups for lists, since both groups have an aversion to eating). Another option would be some Rx for eating. I’m sure Cyrene has tried many of them (Megace, Decadron, Reglan, etc.) and found them ineffective. If Cyrene hasn’t, I’d recommend that he give those a try. Possibly with a new doctor (if possible) so he can candidly explain his stituation. Communication between offices is usually pretty poor, so if you leveled with a strange doctor things could be easier, “Hey doc, I’m in constant pain. No, I’m not here for that, don’t worry. My problem right now is that I can’t eat. In the past I’ve used marijuana to treat this problem, but you can understand that it is a less than desirable solution. What I would like is a legal drug that can acheive the same effect.” But if you’ve been through the gambit of all those drugs, fuck it, ask 'em. You’ve already got a morphine Rx, right? Or some other heavy-duty opiate/opiod. It isn’t like you’d be branching deeper into bad territory (technically not true due to silly drug ratings, but most doctors are also human beings who realize what the score is).