Genetic and hormones are the main culprits of hair loss. One leading form of hereditary hair loss in men and women is Androgenetic Alopecia (otherwise known as pattern baldness), which is responsible for 95% of hair loss. Androgenetic Alopecia is characterized by receding hairline and thinning from the crown of the head in the shape of a horseshoe.

With Androgenetic Alopecia hair loss is caused by an increase in testosterone, which leads to too much dihydrotestosterone (DHT), a derivative of testosterone. DHT can cause the blood supply that feeds the hair to become damaged, and it can eventually thin the hair follicle, causing hair to grow out thinner and shorter, until the follicle withers away. Furthermore, the body's immune system senses the follicle is dying, and as part of its defense system tries further to shut it down and get rid of it.