At What Age Does Hair Loss Start? A Timeline for Men and Women Finding extra hair in your brush or shower drain can feel scary. Many people ask the same question: “Am I too young to lose my hair?” The truth is, hair loss can start earlier than most people think. For some, it begins in their late teens. For others, it may not happen until their 40s or 50s. Hair loss is very common for both men and women in San Jose and across the country. Stress, genetics, hormones, diet, and