I've been taking this vitamin for a month. As I work with children one to two years old, I am always exposed to bacteria of viruses and such, for this reason I always had flu and my nails and hair were not growing anymore, after I started taking it I noticed that I rarely get sick and also my nails are growing strong and beautiful, my hair is stronger and the fall has decreased a lot. I take a capsule before going to sleep and I can say that although the result is not overnight, it is very worth starting the intake of this vitamin, I noticed the result with more or less 16 days taking. THE CAPSULES ARE HALF BIG, BUT NOTHING NOT TO SWALLOW. It arrived fast and well packaged.