DHT and Hair Loss: Follicle Sensitivity, Tests and Blockers

What is DHT, and how is it made?

Dihydrotestosterone, usually shortened to DHT, is an androgen formed from testosterone by enzymes called 5-alpha-reductases. Conversion occurs in several tissues, including the skin and hair follicles. DHT acts through androgen receptors within cells.

DHT is a normal hormone with roles in male sexual development and androgen-dependent hair growth. It should not be treated as a toxin that everybody needs to eliminate. A medication that changes its production or action needs an individual reason for use and a discussion of possible unwanted effects.

Why can androgens grow a beard but thin scalp hair?

Hair follicles do not all respond alike. Androgens can promote the development of thicker facial or body hair while contributing to miniaturisation in susceptible scalp follicles. Randall’s review of androgen action describes this response as dependent on the body site and the biology of the follicle itself.

This is why having substantial facial hair and a receding hairline is not a contradiction. It also explains why a single hormone value cannot predict how every region of a person’s hair will behave.

How does DHT cause pattern hair loss?

In susceptible scalp follicles, androgen signalling alters the growth cycle and contributes to miniaturisation. The growth phase becomes shorter, and hairs can become finer and shorter over successive cycles. This reduces the coverage provided by the same area of scalp.

The process is central to androgenetic alopecia, especially male pattern hair loss. It is different from a sudden episode of widespread shedding after illness or childbirth, or autoimmune alopecia areata.

The cycle terminology is useful here: anagen is growth, catagen is transition, telogen is rest and exogen is shedding. A resting follicle can produce a new hair when it re-enters the growth phase. The balance between growth, rest and shedding changes in hair disorders.

In men, susceptible regions commonly include the frontal scalp, temples and crown. The sides and back often retain more coverage. These differences underlie both the familiar pattern of loss and the assessment of potential donor hair for transplantation.

Women more often develop thinning over the top of the scalp and a widening parting. The role of androgens in female pattern hair loss is less straightforward than in male baldness; the same explanation should not be applied to every woman without assessment. A clinical pattern also cannot establish whether a person has excess circulating androgens.

Why are some people more sensitive to DHT?

Inherited susceptibility involves several genes and can come from both sides of the family. The androgen receptor gene is relevant, but a single gene or a relative’s hairline cannot reliably predict an individual’s future baldness.

The clinically important question is how susceptible follicles respond over time. Two people with similar blood hormone levels may have very different hair density. Age, the duration of miniaturisation and other causes of shedding can also influence what is visible.

A clinician assesses the distribution and progression of loss rather than diagnosing “high DHT” from a photograph. Trichoscopy can help identify variation in hair diameter and signs of miniaturisation. It can also reveal features that suggest a different scalp disorder.

In women, hormonal investigation may be appropriate when thinning accompanies irregular periods, acne or new excessive facial hair. Hair changes around menopause also deserve an assessment if progressive or distressing. The aim is to identify a relevant clinical problem, not assume that all hair loss is caused by one hormone.

Do you need a DHT blood test for hair loss?

A normal DHT result does not rule out androgenetic alopecia, and a high result does not prove it. In a small study involving 49 people, Urysiak-Czubatka and colleagues found that serum DHT did not reliably distinguish those with androgenetic alopecia from controls or correlate with its severity. The study is small, but it illustrates the limits of using this blood value as a baldness score.

A diagnosis usually starts with the history, scalp examination and pattern of change. Blood tests answer specific questions raised by that assessment. For example, a clinician may investigate thyroid function or iron status when symptoms suggest another cause of shedding, or selected hormones when there are signs of androgen excess.

Reference ranges vary by laboratory, method, age and sex. An isolated number taken from an online “normal DHT” chart should not be used to choose a medicine or increase a dose. Ask what a proposed test will change about diagnosis or treatment before paying for a broad panel.

What do DHT blockers actually do?

“DHT blocker” is a broad consumer label. It can refer to medicines that reduce DHT formation, medicines that interfere with androgen action, or supplements marketed with much weaker clinical evidence. These are not interchangeable categories.

Approach	Main limitation
Finasteride	Prescription, side effects
Dutasteride	Off-label for hair loss (UK)
Antiandrogens (spironolactone)	Limited to selected cases
Minoxidil	Not a DHT blocker
Herbal “blockers”	Weak, inconsistent evidence

Finasteride and dutasteride

Finasteride 1 mg is an oral prescription treatment for male pattern hair loss. It reduces the conversion of testosterone to DHT. It can slow progression and improve growth in some men, although preserving existing coverage may be the main benefit.

The photograph shows bottles labelled 5 mg. The oral finasteride dose licensed for male pattern hair loss is 1 mg; the pictured strength is not a dosing instruction. Always use the prescribed product and dose.

Dutasteride suppresses DHT more strongly, but a greater biochemical effect does not automatically mean a better individual choice. Its use for hair loss is off-label in the UK. A prescriber must consider the evidence, medical history, adverse effects and alternatives rather than select treatment from a ranking of hormone suppression alone.

Both medicines require a discussion of sexual and psychiatric adverse effects. For finasteride, the MHRA warns that sexual dysfunction may persist after stopping; the newer psychiatric warning for dutasteride is precautionary because evidence for that medicine is more limited. For finasteride 1 mg, patients who develop depression or suicidal thoughts should stop treatment and contact a healthcare professional promptly. People taking finasteride 5 mg or dutasteride who develop psychiatric symptoms should contact their prescriber for advice. Immediate danger requires emergency help.

Does topical finasteride avoid systemic effects?

Topical treatment can reduce systemic exposure compared with an oral formulation, but topical does not mean that none reaches the bloodstream. In a 24-week randomised trial in men, topical finasteride improved the measured hair count compared with placebo and produced lower blood drug concentrations than oral treatment. It nevertheless also reduced serum DHT.

These findings concern the formulation and patients studied. They do not establish that every compounded spray is equivalent, that uncommon adverse effects are impossible, or that results apply to women. Discuss the actual product, its licensing status, application precautions and risks with the prescriber rather than relying on the word “topical”.

What about spironolactone and other antiandrogens?

Spironolactone may be prescribed off-label for selected women with female pattern hair loss. It acts on androgen signalling rather than working in exactly the same way as finasteride. It has pregnancy restrictions and can affect blood pressure and potassium, so suitability and monitoring require clinical assessment.

Products such as topical antiandrogens should be judged individually. Laboratory activity or a small study does not establish a medicine as a standard UK treatment. Buying an unfamiliar “blocker” online is not equivalent to having a diagnosis and a supervised prescription.

Which hair treatments do not block DHT?

Minoxidil is a hair-growth treatment with a different mechanism. It may be considered for male or female pattern hair loss according to the product and clinical situation. Irritation, unwanted hair growth outside the application area and an initial increase in shedding can occur. Treatment effects develop over months, and benefit generally diminishes after stopping.

Combining treatments can sometimes be appropriate, but each component needs its own rationale. A product that contains minoxidil and finasteride combines different mechanisms; minoxidil alone should not be presented as lowering DHT.

PRP involves processing a blood sample and injecting a platelet-rich preparation into the scalp. Research has reported improvements in some people with pattern hair loss, but preparation and treatment schedules vary. It is not an established method of normalising DHT or a guaranteed replacement for prescribed treatment.

PRP injections can cause pain, bruising, bleeding or infection. PRP is not included in Body Expert’s standard hair transplant package; any additional treatment should be specified separately in the quote.

Low-level light devices have also been studied for pattern hair loss. Some trials report improved density, but their proposed effects are not equivalent to blocking androgen receptors. Evidence from one device or schedule should not be assumed to apply to every light product.

The appearance of the hair shaft and the biological activity of the follicle are separate issues. A product can improve softness or reduce breakage without changing DHT production or treating miniaturisation. Keep those goals distinct when comparing shampoos, conditioners and medical treatments.

Can foods or supplements lower DHT enough to stop hair loss?

A balanced diet supports health, and correcting a relevant deficiency can help when deficiency contributes to shedding. This does not establish that taking additional vitamins will block DHT in a person with adequate nutrition.

Saw palmetto, pumpkin seed preparations and other plant extracts are marketed for their proposed effects on androgen pathways. Some have been studied, but the evidence is much less established than for licensed treatments and varies by preparation. Findings in cells or animals do not tell us that eating a food or using a shampoo will preserve scalp hair in humans.

“Natural” also does not mean free from adverse effects or interactions. Tell your clinician about supplements, particularly if you take medicines or are planning pregnancy. Be cautious about products promising a specific percentage of DHT reduction without showing what that means for hair density, tolerability and long-term outcomes in people.

The practical questions are: Was this exact product tested in people with my diagnosis? Was there a comparison group? What changed in the hair, rather than only a laboratory marker? These questions are more useful than the length of an ingredient list.

Does a hair transplant solve the DHT problem?

A transplant redistributes follicles from a suitable donor area into areas needing coverage. Donor follicles are generally selected for their relative resistance to the process affecting the frontal scalp and crown. They are not an unlimited or absolutely immune resource.

A hair transplant assessment should consider the donor area’s quality and limits, the likely pattern of future loss and the amount of coverage that can realistically be achieved. A Norwood stage alone does not establish candidacy.

The procedure does not lower DHT or stop thinning of surrounding native hair. This is why the surgeon may discuss ongoing medical management even after successful graft growth. Surgery and medical treatment address different aspects of the long-term appearance.

Ask how the plan would look if untreated hair continues to thin. A conservative hairline, adequate donor preservation and clear expectations can matter more over time than a promise of maximum density in one session. Surgery has risks, including scarring, infection and an unsatisfactory result, and needs appropriate aftercare.

Planning treatment and follow-up with Body Expert

For someone considering surgery after a diagnosis of pattern hair loss, an initial exchange and photographs can help assess whether a consultation is appropriate. They do not replace examination of the scalp or investigations needed for unexplained shedding or inflammation.

Body Expert’s standard hair transplant support includes a five-star hotel with breakfast, VIP transfers between the airport, hotel and clinic, an English-speaking coordinator and 12 months of postoperative follow-up. Flights are not included. The personalised quote should state the procedure, services and any optional additional treatment.

The clinical discussion should cover who performs each stage, which harvesting and implantation methods are proposed, the available donor supply and the recovery plan. A technique name does not determine whether a patient should take a DHT-targeting medicine; that remains a separate prescribing decision.

During follow-up, compare consistent photographs and review both transplanted and native hair. Ask whom to contact about scalp concerns and whom to contact about medication side effects. A useful plan explains the purpose of each treatment, how progress will be assessed and when it should be reconsidered.

Questions to take to your appointment

• Does the examination support androgenetic alopecia, or is another cause contributing?
• Would a blood test change the plan, and which specific question would it answer?
• Is the proposed treatment reducing DHT, blocking androgen action or supporting growth through another mechanism?
• What benefit is realistic, how long should assessment take and which side effects need action?
• If I stop treatment or continue losing native hair after surgery, how will that affect the longer-term result?

Understanding DHT is useful when it leads to a clear diagnosis and an informed treatment choice. The goal is not to chase the lowest possible hormone value; it is to find an approach that offers a worthwhile benefit for your hair and remains acceptable for your health and daily life.

Sources

Randall, V. A. (2008). Androgens and hair growth. Dermatologic Therapy, 21(5), 314–328. Read source

Urysiak-Czubatka, I., Kmieć, M. L., & Broniarczyk-Dyła, G. (2014). Assessment of the usefulness of dihydrotestosterone in the diagnostics of patients with androgenetic alopecia. Advances in Dermatology and Allergology, 31(4), 207–215. Read source

Piraccini, B. M., Blume-Peytavi, U., Scarci, F., Jansat, J. M., Falqués, M., Otero, R., Tamarit, M. L., Galván, J., Tebbs, V., Massana, E., & Topical Finasteride Study Group. (2022). Efficacy and safety of topical finasteride spray solution for male androgenetic alopecia: A phase III, randomized, controlled clinical trial. Journal of the European Academy of Dermatology and Venereology, 36(2), 286–294. Read source

Kaiser, M., Abdin, R., Gaumond, S. I., Issa, N. T., & Jimenez, J. J. (2023). Treatment of androgenetic alopecia: Current guidance and unmet needs. Clinical, Cosmetic and Investigational Dermatology, 16, 1387–1406. Read source

Almohanna, H. M., Ahmed, A. A., Tsatalis, J. P., & Tosti, A. (2019). The role of vitamins and minerals in hair loss: A review. Dermatology and Therapy, 9(1), 51–70. Read source

Goldin, J., Zito, P. M., & Raggio, B. S. (2025, August 2). Hair transplantation. In StatPearls. StatPearls Publishing. Read source

McNeil Products Ltd. (2025, January 3). Regaine for Men Extra Strength Scalp Solution 5% w/v Cutaneous Solution: Summary of product characteristics. Electronic Medicines Compendium. Read source

Gloucestershire Hospitals NHS Foundation Trust. (2026, July). Spironolactone for female pattern hair loss (GHPI1956). Read source

Medicines and Healthcare products Regulatory Agency. (2026, May 11). Finasteride and dutasteride: Updated safety warnings for psychiatric side effects and sexual dysfunction. Read source