I started taking Biotin about a month ago when my sister in law recommended it to me because I was experiencing some horrible hair loss thanks to a shampoo I was using *damn you Neutrogena T Gel version dandruff shampoo*. I looked for it at my CVS in the vitamin section and did find it there in the I believe it was the Nature's Bounty brand and it was about $13.00 or more. Don't buy it there or in that brand. The best place is Target..they have it there in the Origin brand..blue bottle..in the vitamin section where you would find vitamins like B12, Vitamin C, etc...and it is only $1.94 a bottle! It comes in 1000mcg and you usually get about 100 tablets to a bottle. I have been taking at least one a day for the past month and have seen considerable difference in my hair growth! My hair has grown probubly about two inches in a month..maybe a little more than that! Alot of other people have said that they also see a difference with their nails...it is suppossed to be great for those as well..I haven't saw much of a difference with my nails, but then again I have only been taking one pill a day..I am going to move it up to two pills a day and see what that does for me. Biotin is very safe and there are no current known side effects from taking it. It is a dietary supplement and water soluable so it doesn't stay in your body, it gets flushed out the same day. That is why you have to take it everyday. Biotin is in prenatal vitamins. That is why alot of pregnant women say their hair grows really quick or their nails grow really fast while they are pregnant, it is because of the biotin in their prenatal vitamins. I personally highly recommend taking Biotin. It has done wonders for my hair! Below is a picture of what the bottle looks like that I am talking about.
Here is a link to the Wikipedia deffinition and more information on Biotin..
If you need more information about Biotin, just GOOGLE it...there are a ton of reviews and different information sources for it!