I've been using Jamieson Biotin 10,000mcg (10x stronger) for about a month now and I have already seen some marginal improvement in hair growth. I am taking it because I have poly cystic ovary syndrome which results in thinning hair and hair loss. The price is right, and I am happy to be supporting a Canadian company. I find it odd that mine came in a 45 capsule bottle, as that is only a month and a half. I would like them to consider having 30 or 60, not just 45. According to the bottle it should only be used for one month consistently at a time, and if you are using it beyond that you should consult a doctor. However, as it's part of the vitamin B family, your body naturally gets rid of excess anyway. Follow the directions and you'll be on the road to better skin, hair, and nails!

Biotin is a product where you have to weigh the benefits with the drawbacks for me. I took it to try and remedy hair thinning from taking an immune suppressant biologic medication for a chronic illness, to try and save my very long, typically thick hair. While it did eventually slow down my hair loss, and bring a little shine back to my dulling hair, it caused a pretty horrific cystic acne breakout for me. I am still battling it three months later, just finding it slowing down now. People will argue that it causes acne, that there's no proof that it does, and that if FIGHTS acne (oddly enough) - I can only tell you of the 2 times I've been on Biotin, I've ended up with the worst breakouts of my life, and I typically only have very mild acne.
But for helping slow my hair loss, I have to say the benefit outweighed that for me. Hopefully I don't have to use this again though.