Testosterone and its role in Alopecia

Hair loss, more commonly known as alopecia , affects millions of men around the world. While some forms of baldness are age-related, the most common form in men, called androgenic alopecia , is often influenced by a key hormonal factor: testosterone . In this article, we’ll explore the link between testosterone and hair loss, focusing on how these hormones influence the hair loss process and what it means for men who suffer from it.

What is testosterone?

Testosterone is an androgenic hormone, produced primarily in the testes in men and in the ovaries in women, although in smaller amounts. It is responsible for the development of male characteristics such as beard growth, muscle mass development, and voice maturation. This hormone also plays a crucial role in libido, sperm production, and maintaining bone density.

But testosterone isn't all good; it's also associated with some less desirable effects, such as androgenic alopecia , which causes progressive hair loss in men.

Androgenic Alopecia: The Most Common Form of Male Hair Loss

Androgenic alopecia , also known as male pattern baldness, is an inherited form of hair loss. It affects up to 50% of men by the age of 50. This condition is characterized by a receding hairline, hair loss at the crown of the head, and an overall decrease in hair density.

Androgenic alopecia occurs when hair follicles become sensitive to dihydrotestosterone (DHT) , a derivative of testosterone. Although testosterone itself does not directly cause hair loss, its derivative DHT is a major player in this process.

The role of DHT in hair loss

Dihydrotestosterone (DHT) is a hormone derived from testosterone by the action of the enzyme 5-alpha reductase . DHT is about five times more potent than testosterone and is essential for the development of male sexual characteristics during puberty. However, this hormone also has a negative effect on hair follicles.

In men who are genetically predisposed to androgenic alopecia, DHT binds to receptors on hair follicles in the scalp. This interaction causes the hair follicles to miniaturize, resulting in a shortened hair growth cycle. The hair becomes increasingly thin and short until the follicle stops producing new hair altogether.

How does DHT work on hair follicles?

DHT shortens the length of the anagen (growth) phase of the hair cycle and prolongs the telogen (resting) phase. Affected hair follicles therefore produce thinner, less pigmented and more fragile hair, eventually leading to its loss. This process is particularly noticeable on the crown and temples, which are more sensitive to DHT. This is why men with androgenic alopecia often develop a horseshoe-shaped baldness, leaving the hair on the sides and back of the head relatively untouched.

Factors influencing alopecia and testosterone

Androgenic alopecia is primarily influenced by two factors: genetics and hormone levels. Men who have a genetic predisposition to androgenic alopecia are more likely to have their hair follicles affected by DHT. If a man has a family history of baldness, especially on his mother's side, he is more likely to develop androgenic alopecia.

Testosterone Levels and Hair Loss

An important point to note is that not all men with high testosterone levels experience hair loss. It is not the total testosterone level that matters, but rather the sensitivity of the hair follicles to DHT. Some men with normal or even low testosterone levels may still experience significant baldness due to this increased sensitivity. The amount of the enzyme 5-alpha reductase present in the scalp may also play a role, as it determines how much testosterone is converted to DHT.

Symptoms and progression of androgenic alopecia

Androgenic alopecia typically follows a predictable pattern, commonly referred to as the Norwood scale . It begins with a gradual receding of the hairline at the temples, followed by thinning at the crown. Eventually, these two areas converge, leaving only hair on the sides and back of the head.

The rate of progression varies from person to person. Some men may start losing their hair as early as their late teens, while others may not see a significant impact until their 30s or 40s. Genetics, hormonal, and environmental factors can all affect how quickly this progression occurs.

Treatments for androgenic alopecia and the role of testosterone

One of the most frustrating aspects of androgenic alopecia is that it is progressive and permanent if left untreated. Fortunately, several treatment options exist to slow or even reverse DHT-related hair loss.

1. DHT inhibitors

DHT inhibitors, such as finasteride , are among the most popular and effective treatments for androgenic alopecia. Finasteride works by blocking the enzyme 5-alpha reductase, preventing the conversion of testosterone to DHT. By reducing DHT levels in the scalp, finasteride can help slow hair loss and even encourage regrowth in some cases.

However, because DHT is also important for other bodily functions, including libido and prostate health, some men may experience side effects such as impaired sexual function while taking these medications. So it's crucial to talk to a doctor before starting treatment.

2. Minoxidil

Minoxidil is another common treatment for androgenic alopecia. Unlike finasteride, minoxidil does not block DHT, but it works by increasing blood flow to the scalp and stimulating hair follicles. This can prolong the anagen phase of the hair cycle and promote thicker hair growth.

Minoxidil is typically applied topically to the scalp, and while it may be effective in slowing hair loss, it does not directly treat the underlying cause related to DHT.

3. Platelet-rich plasma (PRP) therapies

PRP (platelet-rich plasma) injections are an emerging method for treating hair loss. This procedure involves taking a blood sample, centrifuging it to concentrate the platelets, and then injecting the plasma into the scalp. Platelets contain growth factors that can stimulate hair follicle regeneration and promote hair growth.

4. Hair transplant

Hair transplantation is a permanent solution for men with advanced androgenic alopecia. This procedure involves harvesting hair follicles from areas where hair is resistant to DHT (usually the sides and back of the head) and transplanting them to the balding areas. The transplanted hair retains its resistance to DHT, providing a long-lasting solution.

Prevention of testosterone-related alopecia

Although it is impossible to completely prevent androgenic alopecia in genetically predisposed men, there are ways to slow the progression of hair loss. Here are some tips that may help:

• Consult a dermatologist : If you start to notice hair loss, see a specialist early to discuss treatment options.
• Avoid excessive stress : Stress can worsen hair loss. Stress management techniques like yoga, meditation, and regular exercise can help minimize its impact.
• Maintain a balanced diet : Nutrients like zinc, iron, B vitamins, and biotin play an important role in hair health. A balanced diet can help support healthy hair growth.