You are right its not FDA approved but if there were major side effects ppl would start posting about them frequently. I mix 15 ML of minoxidil and .75 gram of RU. I use about half of a ML of the solution Morning and evening. It has been working great for me and I dont experience any of the side effects that i had was getting on Propecia.
I've bought from Androgen Inc., Kanes, American Applied Chemical Company, and most recently from **.com. never had a bad experience but ** seems to have the lowest price and provides sufficient evidence that it is 99% pure.
Hope this helps you guys Ive had great results on both Propecia/Minoxidil and now RU/Minoxidil but rarely miss the twice per day applications.