Hair loss

Hair loss, also known as androgenic alopecia or pattern baldness, is a condition associated with aging, with research suggesting that premature baldness is a sign of premature aging 1. The condition affects both men and women, with estimates suggesting that it affects 50 to 100 percent of White men and women, and to a lesser degree minorities 1. However, the androgen hypothesis, which suggests that androgens such as testosterone are the primary cause of hair loss, has been widely disputed and is no longer considered a viable explanation for the condition 6.

In fact, studies have shown that women with polycystic ovarian syndrome (PCOS), a condition characterized by high levels of androgens, often experience hair loss, but this is not due to the androgens themselves, but rather due to the underlying hormonal imbalance 3. Similarly, women taking oral contraceptives, postpartum mothers, and post-menopausal women also experience hair loss, which is not explained by the androgen hypothesis 5.

Research has also shown that the hormonal pattern of men with premature balding resembles that of women with PCOS, characterized by high levels of estrogen, cortisol, and other "stress" hormones, and low levels of protective "youth-associated substances" such as pregnenolone and progesterone 4. Furthermore, studies have found that higher levels of TSH and prolactin are common in both men and women with pattern baldness 4.

The treatment of hair loss is still an unmet need, with current treatments such as finasteride and androgen pathway inhibitors having significant side effects 6. In contrast, testosterone therapy has been shown to reverse hair loss in women, suggesting that the androgen hypothesis is incorrect and that hair loss is not caused by androgens 8.