In life we can often see some male friends appear to have a raised hairline or even no hair on the top of the head. People often tease that the smartest and smartest head does not grow hair. Why does “shedding” only appear in male friends? “Is it really a sign of intelligence? Can hair transplantation cure “topping out”? “It is definitely not a sign of intelligence. “Foreign surveys have found that about 25% of 25-30 year old men, 40% of 40 year old men, and 50% of 50 year old men exhibit varying degrees of hair loss, known as Male Pattern Baldness (MPB). MPB is also known as premature baldness, lipoatrophy, and commonly referred to as “shedding”. It is called Androgenetic Alopecia because it is not only influenced by family genetics, but also by androgenic hormones. The vast majority of patients who ask about male pattern baldness have a family history of hair loss. Many believe that the disease is autosomal dominant, while others believe that it is polygenic. However, men with a family history of alopecia are no longer affected by the disease when they are debulked before puberty (that is, when the reproductive system of the animal is chemically or surgically removed or rendered inoperable), but hair loss can occur again when androgen therapy is administered. This shows the joint role of genetics and androgens in the development of the disease. Is the cause of “shedding” related to local blood circulation. Orentrich et al. experimentally transplanted hair follicles from alopecia areata to both alopecia areata and non-alopecia areas, and no hair grew. In contrast, when hair follicles from non-alopecia areas were transplanted to both alopecia and non-alopecia areas, the hair grew well and maintained its original growth characteristics. The experiments suggest that hair loss is not related to the local blood supply to the scalp, but rather to the hair follicle itself. Further studies have revealed that the skin contains more androgens, dehydroisandrosterone (a weaker androgen), and 5αC reductase that converts dehydroisandrosterone into stronger androgens (testosterone and DHT). The binding of testosterone and DHT to the receptor, phosphorylation and receptor sulfhydryl reduction produce androgen-receptor complexes that enter the nucleus and bind to genetic loci, thereby stimulating or altering the internal processes mediating hair growth, inhibiting adenylate cyclase activity, and shortening the anagen phase and reducing the diameter of the hair follicle. Women have more than three times less 5αC reductase in the hair follicles on the top of the head than men, while there is a cytochrome P450 aromatase specifically present in the outer hair root sheath of the hair follicle in the scalp at 2-5 times higher levels than in men, and its role is to convert testosterone and androstenedione into estradiol and estrone. This is why women have relatively little baldness, and even when they do lose hair, it is not the “shedding” that occurs in men, but mostly scattered hair loss, which is characterized by varying degrees of hair thinning. The androgen receptors and 5αC reductase in the frontal and parietal scalp are higher than in the occipital area; at the same time, there are more cytochrome P450 aromatase in the occipital scalp. Therefore, the occipital hair will not fall out, and the hair transplanted to the forehead and the top of the head will also be the same as the occipital hair and will not fall out. “Shedding” not only affects the appearance, but also brings a certain degree of psychological stress to those who have hair loss, affecting self-confidence. There are numerous medications available to treat hair loss, which means that conservative treatment is inaccurate. Dr. Li Hui suggests that the real and effective way to improve the appearance of patients is still hair transplantation, as mentioned above, to take out a small portion of your own occipital hair and transplant it to the top of the forehead, which will maintain the original characteristics of the hair and will not lose hair.