This procedure can permanently restore lost hair by transplanting follicles from thicker areas of your scalp to the balding regions.
For most men, it happens between ages 30 to 45. If you start losing hair in your 20s, it often slows around 30 and is clearly defined by 40 or 50.
In women, hormone-related hair loss is less predictable. But it typically settles around menopause in the 40s, 50s or 60s.