Currently, the hormone DHT (Dihydrotestosterone) has been significantly linked to baldness.
Baldness is very common in society and affects men more than women. Fifty percent of men over the age of 40 develop baldness—one in two—and women are not spared: 30% of them between the ages of 40 and 40 suffer some degree of baldness.
For some reason, there’s a common misconception that baldness is caused by a hormone—in men, testosterone—which is false. In 95% of men, baldness is genetic, not hormonal.
Testosterone and men
In men, testosterone is a hormone that plays an important role in the development of male reproductive tissues, such as the prostate and testes. It also plays a role in the development of secondary sexual characteristics, such as increased muscle mass, bone mass, and body hair growth. Therefore, testosterone is essential for the health and well-being of the male body.
What is the hormone Dihydrotestosterone?
Dihydrotestosterone (DHT) or androstanolone is an androgen, the biologically active metabolite of the hormone testosterone, synthesized primarily in the prostate, testes, hair follicles, and adrenal glands by the enzyme 5α-reductase. This enzyme reduces the double bond of the testosterone hormone. When testosterone reaches the hair, due to the presence of the enzyme 5-alpha-reductase type 2, it is converted into DHT (dihydrotestosterone), influencing hair growth, causing follicles to die or become damaged due to the inhibition of nutrient absorption. Therefore, men who have a higher amount of this enzyme in their hair experience greater hair loss and develop alopecia.
Why does the hormone DHT cause hair loss in men?
Androgenic alopecia is the most common cause of hair loss in both men and women. It is inherited in a polygenic pattern and is caused by the action of androgens. Genetically, it causes a progressive miniaturization of scalp follicles as a result of the action of 5-alpha-dihydrotestosterone. Testosterone is converted to dihydrotestosterone by the action of 5-alpha-reductase, so its accumulation inhibits follicle metabolism, stimulating growth from terminal to vellus hair. This only occurs on the scalp, such as in the fronto-parietal region or the vertex.
The process can begin at any time after puberty. In males, it begins with delayed fronto-parietal growth (resulting in the so-called receding hairline). It later affects the biparental area and the vertex (tonsure hair removal), always sparing the lateral and posterior areas of the scalp.
Why does the hormone DHT cause hair loss in women?
Bald women are deficient in an enzyme called aromatase, a protective enzyme against baldness. When testosterone reaches the hair, it is converted into estrogen (female hormones). The conversion of testosterone to dihydrotestosterone is regulated by an enzyme, 5-alpha reductase, on the scalp. Over time, the action of DHT causes the follicle to degrade and shorten its growth phase. The hair progressively thins until it becomes so fine that it cannot withstand daily combing.
There are two possible stages of hair loss in women: from age 20 to age 50. Hair loss lasting longer than three months, with thinning hair, is an early sign that baldness may be developing in women.
How to stop the hormone Dihydrotestosterone ?
To control the appearance of the hormone DHT in the hair, testosterone itself should not be removed; rather, the enzyme derived from it must be blocked. Blocking the enzyme is achieved through appropriate medications tailored to the patient’s characteristics, preventing the conversion of testosterone to dihydrotestosterone. This prevents the progression of baldness and restores between 20 and 30% of hair. Medications are administered orally, injected, or applied directly. There are various products that help with this, although the active ingredient approved by the FDA and COFEPRIS is finasteride or dutasteride.
Most hair prevention and treatment products are on the market, but research is necessary to select the most effective options for each patient.
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