What are the "hair-growth" pills/vitamins called, and where can I get them?

-I've been told certain pills or vitamins make your hair grow but I'm unsure where to buy them and what they're called, help!I use Nioxin Intensive Therapy Recharging Complex http://www.amazon.com/gp/product/B001394鈥?/a> This product works for me. Hair has grown longer and thicker.