Why Does the Human Scalp Donor Zone Persist? An Evolutionary Hypothesis of Differential Follicular Preservation

Androgenetic alopecia is affected by scalp DHT levels, not sensitivity, with treatments like finasteride and dutasteride aiming to optimize these levels. Personalized DHT management is crucial for effective hair growth.

Minoxidil and finasteride are more effective for diffuse thinning and crown balding because these areas have miniaturizing but still alive hairs that respond well to treatment. The hairline is less responsive to these medications due to its androgen sensitivity and often requires a transplant for restoration.

Balding scalps have more androgen receptors, leading to increased TGF-beta, which causes blood vessel loss and hair follicle miniaturization. Blocking androgen signaling and TGF-beta may help prevent hair loss.

Hair loss is linked to cellular physiology and the IGF-1 to TGF-B1 ratio, not just androgen sensitivity. The theory lacks evidence, while finasteride and minoxidil are effective treatments.

The conversation discusses hair loss treatments, focusing on the use of topical minoxidil, microneedling, finasteride, and dutasteride, while debating the role of testosterone and DHT in hair loss. It also touches on the potential liver health impacts of these treatments and the genetic sensitivity of hair follicles to androgens.

The post discusses a theory that hair regrowth after transplant is due to the angiogenesis process (new blood vessels forming), not because the transplanted hair is unaffected by DHT. The responses highlight the established belief in 'donor dominance' (the importance of the hair's origin in transplantation) and skepticism about the new theory.