Exploring DHT's Role and Effects for Hair Preservation

Testosterone is generally considered a virtual symbol of manliness, aggression, and strength – a bit of misrepresentation since women also have testosterone.
Another sex hormone, dihydrotestosterone (DHT), is an androgen and plays a similar role in male sexual development as testosterone. You may have read about the DHT hormone in relation to hair loss and seen ads for DHT blockers. In this article, you will learn what DHT is, its functions, and most importantly, how it is associated with hair loss, and if there is a proven solution.

Read on to learn more about the DHT hormone, what it does, and how it can affect hair loss.

What is DHT?

Dihydrotestosterone is a potent androgen or male sex hormone that plays a critical role in developing primary and secondary male sexual characteristics. It is a metabolite of testosterone and is much more potent than its precursor. This conversion takes place in the skin, prostate, and liver with the help of an enzyme known as 5 alpha-reductase. It can also rarely be synthesized from other organs. Up to 10% of the testosterone is converted into DHT.

DHT helps develop male genitals, including the penis, scrotum, and prostate (Kinter, 2021). The DHT causes the development of secondary male sexual characteristics, including facial hair growth, body hair (pubic and under arm hair), increased muscle mass and deepened voice.

DHT can also be responsible for certain medical conditions during adulthood. One of the most common conditions caused by DHT is androgenic alopecia, commonly known as male pattern baldness, benign prostate hyperplasia (BPH), prostate cancer, and abnormal hair growth in females, also known as hirsutism (Kinter, 2021). Although the role of DHT in women is not entirely understood, higher DHT levels are seen to be associated with the polycystic ovarian syndrome (POCS) and acne breakouts.

DHT vs. Testosterone

Testosterone and DHT are both androgens, but the DHT hormone is much more potent. It binds to androgen receptors more strongly and sticks around longer than testosterone. DHT is made from testosterone by 5-alpha-reductase, an enzyme mainly present in your skin, prostate, and liver. But only 10% of your circulating testosterone is turned into DHT (Kinter, 2021).

While the DHT is more potent than testosterone and binds avidly to the androgen receptors, the testosterone is present more abundantly. Testosterone has widespread effects on various bodily functions, including:

- It increases bone mineral density (BMD)

- It reduces body fat while promoting lean body mass resulting in a healthy body weight

- It protects against various metabolic disorders DHT plays important sexual roles and has more affinity for androgen receptors than testosterone.

Function of DHT

DHT plays a vital role in regulating various functions of the body.

Production of Red Blood Cells

DHT is associated with increased erythropoiesis or red blood cell production. This is why it is used in the treatment of anemia caused by decreased production of sex hormones in older men due to the small gonad size.

Skin

Although the function of DHT is not entirely understood in the skin, it is hypothesized to enhance the skin’s immune function. It also influences the local inflammatory processes of the skin. Skin also plays a vital role in maintaining the DHT levels in the blood.

Body Composition & BMI

DHT helps maintain lean body mass while it increases the process of fat breakdown. Both of these factors help maintain a healthy body mass index (BMI).

Sexual Function

A normal level of DHT is an important requirement of normal sexual function in otherwise healthy young adults. A decrease in the DHT levels can cause sexual problems, including erectile dysfunction, reduced libido, and abnormal ejaculation. These effects are primarily seen in males who take finasteride for benign prostate hyperplasia (BPH).

DHT Hormone and Hair loss

There are several different causes of hair loss—some hair loss can be due to illnesses. At the same time, other types may stem from vitamin deficiencies. However, the most common cause of hair loss is androgenic alopecia (AGA), more commonly known as male pattern baldness. Half of all men will start losing their hair by age 50, and the problem worsens with age (Ho, 2021). While the DHT plays a vital role in male pattern hair loss, interestingly enough, it is responsible for the growth of armpits, pubic and facial hair. These opposite effects on different body parts are not well understood.

Knowing how hair growth works typically is vital to understanding how DHT levels can result in hair loss and baldness.

Our body contains tiny follicle structures called follicles for hair growth. These follicles are present all over the body except for the palms and soles. A single strand of hair grows from one follicle and will keep re-growing from the same follicle in case you shave it off. The growth cycle of hair lasts for about two to six years. When this cycle ends, the hair stays in the follicle in a resting state. The hair will eventually fall off after a few months, and new hair takes its place.

The whole cycle of hair growth can be divided into 3 stages:

Anagen Phase

Most of the hair on our heads (80%) is in the anagen phase, considered the phase of rapid growth. This phase can last for 2 to 7 years and even up to 10 years in some cases.

Catagen Phase

The catagen phase is the degenerative phase of the hair growth cycle, lasting for about 10 to 20 days. During this phase, the hair follicle shrinks and prepares for renewal. About 3% of hair is in this phase of the hair growth cycle at a time.

Telogen Phase

During the telogen phase, the old hair is evacuated from the follicle. This is known as the resting phase. About 12 to 17% of the hair is in the resting phase.

How is DHT linked with baldness?

DHT, along with other androgens, is the culprit of male pattern baldness. The presence of DHT affects the hair follicle in a way to make them miniaturized. Increased levels of DHT make the anagen or growth phase of the hair growth cycle short and shrink the hair follicles, resulting in thinner and more brittle hairs with each cycle. The length of the telogen phase also increases.

As these changes continue, the hairs become soft and are characterized as vellus hairs. Vellus hairs are present on an infant's body and vanish later in response to the androgens (Ho, 2013).

The typical pattern of AGA in men starts at the temples and the vertex (crown) of the head, resulting in a characteristic receding hairline. This hair loss continues until a thin rim of hair is left on the sides and rear of the head.

Treatment Options for AGA

Now that you’re up to speed on what DHT does, how can we stop it from causing problems? Currently, two types of medications are available in the market with evidence of their efficacy. These medications either inhibit the DHT production or block its binding abilities with the androgen receptors.

Finasteride

Finasteride is an NHS-approved solution for the AGA. This medication works as a DHT blocker and is available in oral form. It blocks the production of 5 alpha-reductase responsible for converting testosterone to DHT. Initially developed as a solution for BPH, finasteride was later on tested for male pattern baldness. A 1 mg/day dosage is considered safe and effective for AGA treatment. Finasteride is widely available with the brand name Propecia or Proscar.

Dutasteride

Dutasteride is another DHT blocker that inhibits the production of the 5 alpha-reductase. Although NHS does not yet approve it, dutasteride has been shown to be equally and even more effective than finasteride in the treatment of male pattern baldness by various studies. The side effects of this medication are similar to finasteride.

Minoxidil

Topically minoxidil is considered effective in treating AGA and improving hair growth. If applied twice daily, it can help increase the blood flow to the degenerating hair follicles by dilating the blood vessels. It can take 4 to 6 months to see the effects of this medication.

Biotin

Biotin is considered a popular solution for hair and nail problems. However, the evidence is poor to support the effectiveness of biotin in preventing hair loss or treating AGA.

Do testosterone boosters work?

How well do these medications work?

The efficacy of finasteride has been proven by research. Studies have shown that finasteride can slow balding and hair loss in more than 80% of men and stimulate hair growth in over 60% of men (DailyMed, 2021). Just keep in mind that it takes a few months to see results.

What about the DHT-blocking shampoos?

DHT blocking shampoos are considered helpful in treating male pattern baldness and re-growth. But unfortunately, there is no scientific evidence for the efficacy of this product. Shampoos that contain ketoconazole are known to prevent hair loss. The researchers theorize this to be due to the inhibiting effect of ketoconazole in testosterone production. This eventually results in lower levels of DHT. More research is needed to establish the efficacy of DHT-blocking shampoos (Fields, 2020).

Minoxidil is the only topical medication approved by the NHS for hair growth. It is not a DHT block. It enhances hair growth by increasing blood flow to the hair follicle resulting in better nutrition and hair growth.

Are there any side effects of DHT Blockers?

DHT blockers can potentially cause the following side effects:

• Erectile dysfunction
• Non-alcoholic fatty liver disease (NAFLD)
• Ejaculation disorders
• Decreased libido
• Hyperglycemia
• Increased insulin resistance

Conclusion

Apart from being an important hormone for the development of primary and secondary male sexual characteristics, dihydrotestosterone also plays a crucial role in the AGA or male pattern baldness. The excess of this hormone in females has other implications like PCOS and abnormal body hair. Oral medication like finasteride and topical sprays like minoxidil are strongly supported by evidence in treating AGA by blocking DHT and improving the nutrition of the hair follicle.

Please note that this article is based on information derived from peer-reviewed research and medical societies and government agencies. This information is not a substitute for professional medical advice, diagnosis, or treatment. Don't hesitate to get in touch with your healthcare provider if you have any medical questions or concerns.