It doesn't take anywhere near a billion dollars to test a new medicine, and if there were a good reason for singling it out as worthy of serious investigation, drug companies would probably already be on it.
"Alternative medicine" mostly falls into two categories; procedures which would have to work by mystical mechanisms which our current scientific understanding suggests almost certainly cannot work, which mostly haven't been tested, and traditional folk remedies which could work by the same sorts of mechanisms as ordinary medicine. Most of the latter have been found not to work, since traditional folk remedies are a significant source which pharmaceutical companies investigate in search of new drugs.
The more plausible a piece of "alternative medicine" sounds, the more likely it is to have already been investigated and found not to work.
It doesn't take anywhere near a billion dollars to test a new medicine, and if there were a good reason for singling it out as worthy of serious investigation, drug companies would probably already be on it.
The only good reason a drug company has to investigate a drug treatment is if they can make substantial money on it, which they generally can't with off patent drugs and natural compounds already in use.
In fact, when they have patent medicines for the same malady, they have every interest in seeing that off patent medicines are banned.
From Quora: