Androgenetic alopecia (AGA), commonly called male or female pattern baldness, is the most common form of alopecia, affecting up to 80% of men and 50% of women in the course of their life. AGA is caused by a progressive reduction in the diameter, length and pigmentation of the hair. In men, hair is lost in a well-defined pattern, beginning above both temples. Over time, the hairline recedes to form a characteristic “M” shape. Hair also thins near the top of the head, often progressing to partial or complete baldness. In women, the hair becomes thinner all over the head, with maintenance of the frontal hairline (Ludwig pattern AGA). Androgenetic alopecia in women rarely leads to total baldness.
Androgenetic alopecia in men has been associated with several other medical conditions including coronary heart disease and enlargement of the prostate. Additionally, prostate cancer, diabetes, and high blood pressure have been related to androgenetic alopecia. In women, AGA is associated with an increased risk of polycystic ovary syndrome (PCOS). PCOS is characterized by a hormonal imbalance that can lead to irregular menstruation, acne, excess hair elsewhere on the body (hirsutism), and weight gain.
Dihydrotestosterone (DHT) is a derivative of male sex hormone, testosterone, which women also have in trace amounts under normal conditions. About 10% of testosterone in all adults is converted to dihydrotestosterone (DHT) with the help of the enzyme 5-alpha reductase. DHT is a powerful androgenic hormone that plays a huge role in helping men develop adult male characteristics. Once DHT is freely released into blood stream, DHT tends to bind to a protein called androgen receptor (AR) in different sites. Androgen receptor is a type of nuclear receptor that is activated by binding any of androgenic hormones including testosterone and dihydrotestosterone. Androgen receptor is expressed throughout the tissues of the human body. Studies suggest that variations in the AR gene lead to increased activity of androgen receptors in hair follicles.
Scientists now believe that it’s not the amount of circulating testosterone that’s the problem but the level of DHT binding to androgen receptors in scalp follicles. DHT shrinks hair follicles, making it less possible for healthy hair to survive. Excessive level of DHT can cause quite few other issues such as hirsutism and acnes. Under normal conditions, women have a minute fraction of the level of testosterone that men have, but even a lower level can cause DHT- triggered hair loss in women. When DHT levels rise, DHT is even more of a problem. Those levels can rise and still be within what doctors consider “normal” on a blood test, even though they are high enough to cause a problem. The DHT levels may not rise at all and still be a problem if the activity of androgen receptors is high in your body.
Two critical factors triggered androgenetic alopecia are the level of DHT and the activity of androgen receptor. To treat androgenetic alopecia, one need to minimize DHT level and/or androgen receptor activity. DHT is converted from testosterone with the aid of 5-alpha reductase, there are many pharmaceutical and natural products that can inhibit 5-alpha reductase or reduce testosterone production in the body. Androgen receptor activity is more dependent on AR gene, but there are pharmaceutical and natural products that can lower or inhibit the binding of DHT to androgen receptors.
Saw palmetto extract and pumpkin seed extract are good type II 5-alpha reductase inhibitors because both contain high phytosterols especially beta sitosterol. Clinical studies have shown that taking 100 mg beta sitosterol can stimulate hair growth. EGCG in green tea extract can stimulates human hair growth via its proliferative and antiapoptotic effects on dermal papilla cells also affects Type I 5‐alpha‐reductase activity which converts testosterone to DHT.
The best results from treatment happen when you begin treatment as soon as possible after the hair loss begins because prolonged androgenetic alopecia may destroy many of the hair follicles. The use of anti-androgens after prolonged hair loss will at least help prevent further hair loss and encourage some hair regrowth from those follicles that have been dormant but are still viable, Stopping treatment will result in the hair loss resuming if the androgens aren’t kept in check in some other way. Maintaining your vitamin and mineral levels helps while you’re on anti-androgen medications.