What Is DHT (Dihydrotestosterone)? What Is DHT's Role In Baldness?

DHT, which stands for Dihydrotestosterone (5α-Dihydrotestosterone), is a male sex hormone, an androgen. 5α-reductase, an enzyme, synthesizes DHT in the adrenal glands, hair follicles, testes and prostate. Male and female adults can lose hair as a consequence of changes in the metabolism of androgen in the body - men more commonly than women. DHT plays a major role in hair loss.

Male pattern baldness, also known as androgenic alopecia or androgenetic alopecia, is caused by the hair follicle's sensitivity to DHT. The follicles miniaturize (shrink), resulting in a shorter lifespan and the abnormal production of hair.

The molecular formula for DHT is C₁₉H₃₀O₂.

The most important part of the hair follicle is the dermal papilla (papilla of hair), which is responsible for the growth of hair. The dermal papilla cells divide and differentiate to form new hair follicles. The papilla is in direct contact with the skin's blood capillaries, from which it gets its essential nutrients for proper hair follicle growth. The dermal papilla has a large number of androgen receptors (more in males than females).

A hair follicle (image from Wikimedia Commons)

When DHT gets to the dermal papilla, it undermines the absorption of vital nutrients required for healthy hair follicles. Hair follicles have resting and growing phases - without proper nutrition, their resting stages get longer while their growing phases get shorter.

What is Miniaturization?

Miniaturization in this text refers to the progressive shrinking the hair follicle. Hair grows for shorter periods, becomes lighter, finer and smaller, until it eventually reaches the vellus stage. Vellus hair is light-colored, short, thin and very fine hair - it is barely noticeable and grows on most of the human body, except for on the lips, palms of the hands, soles of the feet, etc. Vellus hair is sometimes referred to as peach fuzz or bum fluff.

Miniaturization occurs because of DHT.

Miniaturization of hair follicle

Experts say that 95% of cases of male pattern baldness occur because of the effects of DHT on the hair follicles. How much DHT people produce depends almost entirely on their genetic make-up - the more that is produced, the greater and more widespread miniaturization is, resulting in greater hair loss.

Two conditions are related to higher levels of DHT:

• Male pattern baldness
• Benign prostatic hyperplasia (BPH) - increase in the size of the prostate

Drugs known as 5α-reductase inhibitors are commonly used for male pattern baldness and BPH. Two examples of 5α-reductase inhibiting drugs are:

• Dutasteride - this medication is approved for BPH treatment. It is also prescribed off-label for male pattern baldness treatment.
• Finasteride - this drug is approved for both BPH and male pattern baldness.

Dunasteride is much more potent than finasteride. However, these types of medications may have side effects that persist even after treatment is over. Side effects may include erectile dysfunction, male breast cancer risk, and a diminished sex drive. Some studies suggest there may even be a higher risk of depression, memory loss and brain fog (inconclusive).