Get checked out at the doctor, if you have too much Testosterone this is a side effect (hence 'male pattern baldness' in the over 30's).
The other contributing factor is diet, eating properly is important, a balanced diet without junk food which contains 'empty calories' in other words lots of calories but no vitamins or minerals.

Don't waste money and valuable time on pills and potions sort out the cause not the effect.
Its like waxing your car when the engine has no oil in it, it doesn't help, wastes time and money (and the engine still seizes)