Initially I took a somewhat desultory look at DS Laboratories Revita Hair Growth Stimulating Shampoo. I was put off by the packaging. Amongst adults I assume I needn't state the obvious. I can only imagine that someone thought this might appeal to follically challenged men with feelings of inadequacy. Anyway, there amongst the ingredients, I spotted spin trap. I swear that sometimes ingredients stalk me.
Spin trap, whose proper name is phenyl butyl nitrone, is a very exciting molecule that can seek out electrons (free radicals) spinning out of control and set them right before they do any damage. I have recently come across it in Mychelle's Fruit Enzyme Mist and YBF Control. This is the first time I have seen it in a shampoo.
This shampoo claims to be anti-DHT (or dihydrotestosterone), which is a powerful form of testosterone that is found in the prostrate and hair follicles. It is responsible for hair loss in men. I don't know quite how Revita deals with DHT, but in addition to spin traps, there are plenty of interesting actives.
There is apple polyphenol, in particular, procyanidin B2 & C1. A trial in Japan in 2000 showed that this outperformed grape and Minoxidil (the hair growth treatment in products such as Rogaine). Various studies show that the apple polyphenol produced more hair and also thicker hair. One report claims it is 200% more effective than Minoxidil.
Revita also has copper peptides, which I have found to be very effective in a hair growth product by Skin Biology called Folligen. There is keoconazole for treating flaky scalps, a red tea from South Africa called rooibos, a 4% dose of caffeine, plus amino acids. The Journal of Dermatological Science published results of a study that demonstrated that carnitine tartrate, another of Revita's ingredients, helped stimulate hair growth. And if all that is not enough there is emu oil, said to stimulate hair follicles, and biotin (a combo of vitamin H and B7 - I have seen claims that it isn't absorbed topically).