Every day, every one of us looses some hair. Our body then replaces it with some new strands as part of the many renewal processes that are built into our body systems. As we all age, 'the reappearance of new hair' event gradually slows down. This observable fact is more evident in men than women, whose 'male-pattern baldness is genetically determined and can begin as early as age 20. For women, hair normally thins after age 50, and considerable hair loss before that age is very rare.