The FDA ban originated because the wording being used by the manufacturers could only be interpreted to mean that Diamaxol is a drug and it is not licenced for sale as a drug. The manufacturers have recently changed their wording to say that Diamaxol is a supplement, which makes it acceptable to the FDA. If you Google "Diamaxol" you will find plenty of comment about it, most of it pretty uncomplimentary. It appears that they sell the same product under several different brand names, each one claiming the product to be targeted at a different specific condition, e.g. diabetes, cancer.
It is widely believed in the States that the whole thing is a scam but,because the ingredients contain nothing harmful and it is no longer being passed off as a drug, the authorities have nothing that they can charge the company's owners with.
It appears there's a great deal of truth in the old saying "a fool and his money are soon parted"!!