And as an addendum to my use of Revivogen, there are a couple of things that "tip" me off that the makers of Revivogen doubt its efficacy.
First, they back up their product with a "90-day money back guarantee." Sounds good, but it also says you won't see results any earlier than after 3 months! So by the earliest point you can see results, you've already blown through the guarantee period. The 90-day money back guarantee is an insult, if you ask me. If they were really so confident they would at least make it 6 months to let you see if the product worked. On the other hand, Propecia offers a full year money-back guarantee. Of course, Propecia is also FDA-approved...the Revivogen makers, despite all the money to be made, have not even submitted their products for approval.
Secondly, it's a kitchen sink product. It combines a lot of wives' tale (IMO) with some scientificially proven ingredients.
Finally, I think it's just shady to sell your hair loss treatment with special shampoo and conditioners that you admit do nothing on their own yet somehow "increase the effectiveness" of the scalp treatment. Looks like a ploy just to make more money if you ask me. I've seen the ingredients in their shampoo, and they are substantially the same as Nioxin and about a million other products that don't do $%* for hair loss...they just make your hair appear thicker. That's not a bad thing, but they should be up front about it instead of saying it increases the effectiveness.
I also was troubled by the documentation they sent along with the outlook, stating it was "important to have a positive outlook." Sounds like they want to encourage that placebo-effect as much as possible, and I'm worried its to cover up the fact that their product doesn't do a whole lot.