If you find that your hair is thinner than it used to be, you can draw some comfort from the fact that you’re not alone. Male pattern baldness affects the majority of men at some stage in their lives. • Approximately 25 percent of men who have hereditary male pattern baldness start losing their hair before the age of 21. • By the age of 35, approximately 66 percent of men will have experienced some degree of hair loss. • By the age of 50, approximately 85 percent of men will have significantly thinner hair.