What is DHT & Its Role in Hair Loss?

Key Takeaways 

• What is DHT? Dihydrotestosterone (DHT) is a hormone derived from testosterone which has a key role to play in pattern baldness.
  
• Is DHT directly responsible for pattern hair loss? Although DHT is required to cause pattern hair loss, it doesn’t follow a simple cause and effect. The hair loss occurs because of a genetic sensitivity of hair follicles to DHT; It is not linked directly to DHT levels, as people with high DHT levels don’t always have pattern hair loss.
  
• How does DHT cause hair loss? DHT causes follicular miniaturisation, a process which leads to hairs becoming thinner and shorter over time, which eventually leads to the follicles producing no new hair. 
  
• Does it affect only men? Both men and women can be affected by DHT-related hair loss, although the pattern this usually occurs in differs between genders. 
  
• Are there any treatments available for pattern hair loss? There are some medications available, particularly for men, that block the production of DHT.  This can prevent further hair loss and potentially strengthen existing hair growth. Treatments that block DHT can slow or stabilise hair loss, but they will require consistent use to show benefit. 

The most common cause of hair loss in men is ‘androgenetic alopecia’ or ‘male pattern baldness’. According to studies, this condition affects up to half of men by the age of 50 and is caused by a genetic interaction between hair follicles and dihydrotestosterone (DHT).

DHT is a hormone that can impact the health of hair follicles, especially in men, who, for genetic reasons, are likely to have male pattern baldness. In this article, we will dig deeper into the actions of DHT on hair and what you can do to prevent hair loss caused by this hormone.

What is DHT? 

DHT (dihydrotestosterone) is an androgen (a hormone responsible for masculine traits) that contributes to the development of male characteristics, including deepening of the voice, growth of body and facial hair, and muscle growth.

DHT is produced when testosterone is changed by the enzyme called 5-alpha reductase. This process occurs in different parts of the body, such as the prostate, skin, and hair follicles.¹

Only about 10% of circulating testosterone is converted to DHT. However, DHT is a potent hormone and only requires small amounts to take effect.

Women also produce DHT, but in smaller amounts.² With a healthy balance of hormones, oestrogen can prevent the influence of androgens on women’s hair follicles. 

However, during hormonal changes such as menopause or PCOS, the protective effect of oestrogen is reduced, exposing follicles to DHT-induced hair thinning.²

Interestingly, DHT is responsible for hair growth in the beard. In the scalp, it often has a different effect, causing hair to thin in the hairline, temples and crown. This just shows that hairs can have a differing response to the same hormones, depending on their genetic programming.  

^{This table summarises some key statistics about hair loss in the UK:}

Category	Statistics
Men with pattern hair loss	Approximately 6.5 million men in the UK are affected by male pattern hair loss at some point in their lives.
Women with pattern hair loss	8 million women in the UK experience female pattern hair loss.
Men with noticeable hair loss	Over 50% of men with hair loss have visible thinning or baldness by their early 50s.
Women post-menopause with thinning hair	After menopause, up to 50% of women may experience noticeable thinning.

How Does DHT Cause Hair Loss?

As mentioned, in people who are genetically predisposed to hair loss, DHT triggers a process called follicular miniaturisation, in which follicles gradually shrink over successive hair cycles until they eventually stop regrowing. 

Miniaturisation Explained:

• Shortened Anagen Phase: The anagen phase is the time when the hair follicle is actively growing hair. The longer it spends in this growth phase, the longer your hair will become. It can last from 2-6 years.  When DHT interacts with your hair
  follicle, it can stop this stage of growth prematurely, causing your hair to stop growing while it hasn’t reached its full length. 
  
• Increased shedding: The shedding (telogen) phase becomes longer than is typical for healthy hair. 
  
• Thinner hair shafts over time: Because DHT can cause the follicles to shrink, they end up producing thinner hair than usual.

Eventually, the follicle may produce only very fine, barely visible hairs. Not every follicle on the scalp reacts this way. 

As a general rule of thumb, the hair follicles on the back and sides of the scalp are more resistant to DHT-induced damage and tend to remain thick and full. This is why we usually refer to this area as the ‘donor zone’ and use hairs taken from here for transplantation into thinning areas 

How to Reduce Your DHT Levels

To manage male pattern hair loss effectively, we usually consider two approaches: either we can directly lower DHT levels in the scalp or protect hair follicles from its effects. 

Current management relies on evidence-based medications that reduce the DHT level in your skin and disrupt its ability to cause you further hair thinning and loss.  

These medications are:

1. 5-alpha Reductase Inhibitors (DHT Blockers)

5-alpha-reductase inhibitors switch off the enzyme (5-alpha reductase) that converts testosterone into DHT.

• Finasteride: Available as an oral tablet or a topical solution, Finasteride is the most common treatment for male pattern hair loss. It reduces DHT levels in the scalp, stabilises hair loss, and, in many cases, promotes partial regrowth.⁵ 
  
• Dutasteride: A more potent alternative, Dutasteride blocks two types of the 5-alpha reductase enzyme (Type I and Type II). It is generally reserved for patients who haven’t seen sufficient results with Finasteride or those with more aggressive hair loss.⁶

2. Growth Stimulants (Non-DHT Related)

It is important to distinguish DHT blockers from other popular treatments like Minoxidil.

While Minoxidil is highly effective at increasing blood flow to the follicle and extending the anagen (growth) phase, it does not change your DHT levels.⁷ Because it doesn’t address the hormonal root cause, Minoxidil is often most effective when used alongside a DHT blocker to provide a two-pronged approach to hair health.

You can read more about combining both treatments in our article on using Finasteride with Minoxidil.

“It is important to stabilise existing hair loss before embarking on having a hair transplant. This ensures the native hair stays in place around the transplanted hair, giving patients a longer-lasting outcome.”

Dr Roshan Vara, Co-founder and Hair Transplant Surgeon at The Treatment Rooms London

Side Effects of DHT Blockers

Most people tolerate DHT-blocking medications like finasteride and dutasteride well and see great benefit from using them, but a small number do notice side effects.⁵ These can include:

• Lower sex drive
  
• Changes in erections or ejaculation
  
• Breast tenderness and swelling 
  
• Temporary increase in hair shedding when starting treatment
  
• Headaches and dizziness 

For many patients, these effects often settle with time or with a change in the dose, or switching from a tablet to a topical form. If symptoms persist, make sure to have a conversation with your doctor who prescribed it about your concerns, and they can adjust as necessary.

How Does Lifestyle Affect DHT Levels?

The role of lifestyle adjustments in blocking DHT is speculative. For a patient with a strong genetic predisposition for pattern baldness, lifestyle changes are most effective when used alongside established medical treatments like Finasteride and Minoxidil.

Diet

A balanced intake of proteins, omega-3 fatty acids, vitamins, and minerals all helps support the function of hair follicles. Avoiding a high-sugar diet may be beneficial, as evidence suggests that high sugar intake may worsen androgen imbalances.⁸

Stress Management

Chronic stress increases cortisol levels in your body, which is a hormone produced by the adrenal glands. High cortisol levels can disrupt the body’s processing of DHT, potentially compounding hair loss.

When to Consider a Hair Transplant

DHT-blocking treatments work best to preserve existing hair, but are not so good at reversing hair loss. When you already have significant hair loss, you may want to consider hair restoration surgery. Hair transplants work as the hair follicles on the back and sides of your head are typically resistant to DHT and remain healthy and productive when moved to the hairline or crown.

Seeking Professional Advice 

The earlier you seek treatment, the more options you leave open to retain good hair density. While DHT-related hair loss is progressive, timely treatment can often slow or stabilise thinning before follicles stop producing hair. Once they lose the ability to produce hair, they often don’t recover.

We recommend consulting your GP or a qualified dermatologist to rule out other causes of hair loss. Once your hair loss has stabilised, often through the use of the medications listed above,  you may then be able to explore surgical hair transplantation options.

Does high testosterone automatically mean elevated DHT?

Not necessarily. High testosterone does not always mean you have high DHT levels. Your genetics will determine your 5-alpha reductase activity and the rate at which your body converts testosterone to DHT. Therefore, two individuals with similar testosterone levels can have significantly different DHT levels.

Why does DHT stimulate beard growth but reduce scalp hair?

The difference lies in how sensitive hair follicles are to DHT damage in different areas of the body. Facial hair follicles appear to thrive under high DHT levels. On the other hand, scalp follicles in the frontal hairline, midscalp, and crown miniaturise when exposed to high DHT levels. 

How long does it take to see improvements with DHT-blocking medications?

If it is used consistently, then a slowdown in hair loss can be expected after 3-6 months. You may also see some regrowth after 6–12 months.

Could DHT blockers affect libido or sexual function?

A small percentage of individuals who take finasteride/dutasteride report diminished libido or erectile difficulty. Your doctor may manage these side effects by reducing the medication dose, decreasing the frequency of administration (e.g., from daily to 2-3 times per week), or stopping the medication entirely.

You can read more about taking finasteride at a reduced dose here.

“We counsel all patients on the risk of side effects with DHT blockers like Finasteride and Dutasteride. It is important you speak to your Doctor before starting them.”

Dr Roshan Vara, Co-founder and Hair Transplant Surgeon at The Treatment Rooms London

Conclusion

DHT is a potent hormone that contributes to male and female pattern hair loss in individuals who are genetically predisposed. 

This hormone makes scalp hair follicles smaller over time, leading to hair having a shorter active growth time and spending longer in the resting phase. Hairs produced becomes smaller and wispier until eventually they are not produced at all. 

There are many different modern treatment methods, including 5-alpha reductase inhibitors (e.g., finasteride/dutasteride), topical agents (e.g., minoxidil), and more permanent solutions, such as hair restoration surgery.

If you suspect that you have pattern baldness, the next best step to take is to consult with a qualified healthcare professional to determine the exact cause of your thinning hair. 

References

1. Kinter KJ, Amraei R, Anekar AA. Biochemistry, Dihydrotestosterone. [Updated 2023 Jul 30]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK557634/

2. Hemalatha A, Pavithra P, Nirmala E, Jayaraman Rajangam. Influential Effects of Dihydrotestosterone (DHT) in Women’s Health. Int J Pharm Pharm Res. 2023;27(4):173–88.

3. Asfour L, Cranwell W, Sinclair R. Male Androgenetic Alopecia. [Updated 2023 Jan 25]. In: Feingold KR, Ahmed SF, Anawalt B, et al., editors. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.; 2000-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK278957/

4. Chaikittisilpa, S., Rattanasirisin, N., Panchaprateep, R., Orprayoon, N., Phutrakul, P., Suwan, A., & Jaisamrarn, U. (2022). Prevalence of female pattern hair loss in postmenopausal women: A cross-sectional study. Menopause, 29(4), 415-420.

5. Zito PM, Bistas KG, Patel P, et al. Finasteride. [Updated 2024 Feb 28]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK513329/

6. Al-Horani RA, Patel P. Dutasteride. [Updated 2024 Mar 20]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2025 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK603726/

7. Suchonwanit, P., Thammarucha, S., & Leerunyakul, K. (2019). Minoxidil and its use in hair disorders: a review. Drug design, development and therapy, 13, 2777–2786. https://doi.org/10.2147/DDDT.S214907 https://emedicine.medscape.com/article/1070167-overview

8. Volk, K. M., Pogrebna, V. V., Roberts, J. A., Zachry, J. E., Blythe, S. N., & Toporikova, N. (2017). High-Fat, High-Sugar Diet Disrupts the Preovulatory Hormone Surge and Induces Cystic Ovaries in Cycling Female Rats. Journal of the Endocrine Society, 1(12), 1488–1505. https://doi.org/10.1210/js.2017-00305