I should say straight away I haven't used this yet, but on paper it appears to have some of the good stuff (e.g. Saw Palmetto, Biotin, Soy Protein), and for a decent price as well. Another upside is doesn't carry any carcinogenic ingredients (ie: PEG etc), many common shampoos do, but I'm cautious about the reviewers claims. Reviews are inherently anecdotal/relative, so much of what is reported could well be placebo effect.
That said though, It's also possible it actually works to some degree too. If the niacin or other ingredients are able to carry that Saw Palmetto follicle deep, then it likely has some good effect as an anti-androgen. I suppose the only way to know is to try. I personally don't know why someone wouldn't simply stick with Nizoral, though. As Ketoconazole has proven track record as an anti-androgen vs the variable data on topical Saw Palmetto.
I've thought about using the conditioner of this set, however. Nizoral's Ketoconazole followed by Avalon's Thickening Conditioner (w Saw Palmetto, Soy Protein, and Biotin) certainly couldn't hurt.