Well this is such a coincidence!!
I HAVE the longest, strongest nails I have had in YEARS....since I started taking 1000mg of glucasamine 4 months ago, which is supposed to help protect your joints!!
It is has definitely cured my thin, splitting nails, not sure if it is doing my joints any good but I will continue purely for the benefit of improving my nails, so try it. It took about 3 months before I suddenly noticed they were actually growing and not flaking or splitting, so takes a while but definitely works!! :D