M.B.
You may need to just take a B vitamin complex with the Biotin. Whenever you are taking a single B vitamin for a specific issue, you always need to make sure to take a B complex (ideally co-enzymated). There are synergies/dependencies amongst the B vitamins. Also, you don't mention how much you are taking. I take 10 mg daily (along with a co-enzymated B-100 complex) and my nails now grow very quickly. I think 2.5 mg would be the minimum one would take to help with nails. Manicures won't help and I personally avoid any of the toxic nail products as those are absorbed through the nails. There are nail products that don't contain as many toxic chemicals, but they still are not as healthy as plain (possibly buffed) nails, which is something you can do at home, to avoid having to breath the toxic fumes in most nail salons. As an aside, people that work in hair/nail salons have higher rates of cancer as compared to others.