The hair follicles that are completely destroyed can never produce hair again, though your body can produce new hair. Realistically we can get to 80% hair reduction. More than this is not realistic to wish for. Under our skin there are thousands of hair follicles that sleep or produce only light fussy hairs. These can be awakened at a later stage of our lives due to hormone changes such as pregnancy or menopause. The use of certain medications or, for example, a period of stress and a lot of effort can also contribute to changes that allow our body to produce hair again. These hairs will be a lot softer and thinner and also grow slower than before.