The most common type of hair loss in adult male and it also called androgenetic alopecia. Male pattern baldness is related to your genes and male sex hormones. The typical pattern of male baldness begins at the hairline. The hairline gradually moves backward (recedes) and hair loss on the top and front of the head, forms an “M” shape and “O” shape baldness. A circular area on the back of the head (vertex) often thins and expands in size over time. Eventually the hair becomes finer, shorter, and thinner, and creates a U-shaped (or horseshoe) pattern of hair around the sides of the head and a bald area on the back of the head.

What are the factors contribute to male pattern baldness?

Age: About 25% of people assigned male at birth see the first signs of hair loss before age 21. By age 50, half experience hair loss, and about 70% will lose hair as they get older.

Hormones: Dihydrotestosterone (DHT) is a type of androgen. DHT is believed to shorten the growth, or anagen, phase of the hair cycle, from a usual duration of 3–6 years to just weeks or months. This occurs together with miniaturisation of the follicles and progressively produces fewer and finer hairs.