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What Are DHT Blockers?: 4 Things to Know

Knox Beasley, MD

Reviewed by Knox Beasley, MD

Written by Sian Ferguson

Published 09/17/2017

Updated 05/03/2024

If you’ve noticed the signs of male pattern baldness — say, a thinning hairline or a bald patch on the crown of your head — a hormone called DHT is probably to blame. It can damage your hair follicles, leading to hair loss. 

The solution? DHT blockers 

As the name suggests, DHT blockers reduce DHT’s effect on the scalp. This can slow down (and sometimes even stop) male pattern baldness.

In other words, DHT blockers are basically your best weapon in the fight against hair loss. 

Below, we’ve explained how DHT can contribute to male pattern baldness, how DHT blockers can combat hair loss and which DHT blockers are worth using as hair loss treatments.

Before we get into the weeds about DHT blockers, let’s have a quick science lesson on DHT.

Short for dihydrotestosterone, DHT is a type of androgen (male sex hormone). Your body produces DHT as a byproduct of testosterone through the action of an enzyme called 5-alpha-reductase. 

Like other androgens, DHT is highly important for your development. During childhood and puberty, DHT is responsible for helping you develop body hair, facial hair and a deep voice.

So if DHT is so important, is blocking DHT bad?

Not when you take DHT blockers at an appropriate age as prescribed by a healthcare professional.

That’s because DHT becomes less important after adolescence — and can sometimes wreak havoc on your hair follicles. As long as you’re taking them correctly, DHT blockers are safe.

Hair Loss Medication

This is where hair regrowth starts

So, what exactly is the link between DHT and male pattern baldness

DHT can damage your hair follicles through a process called miniaturization, in which the anagen (growth) phase of the hair growth cycle becomes progressively shorter — resulting in thinner, shorter hairs. 

Over time, this can lead to a receding hairline, hair thinning and even severe hair loss.

This type of hair loss is called androgenic or androgenetic alopecia. It’s also called male pattern hair loss or male pattern baldness.

But DHT — and androgenetic alopecia, for that matter — aren't exclusive to men. Women also make some testosterone. When DHT causes baldness in women, it’s called female pattern hair loss.  

At its core, hair loss seems to come down to genetics. Some people are just more sensitive to the effects of DHT.  

Researchers believe that men affected by androgenetic alopecia tend to have higher levels of the 5-alpha-reductase enzyme, which converts testosterone into DHT, as well as an increased level of androgen receptor activity in the scalp.

So, while DHT isn’t inherently bad for you, it can be bad news for your hair follicles — especially later in life.

Some certainly do, but they aren’t all created equally. Effectiveness varies.

It’s also important to realize that DHT blockers can’t magically reverse the effects of male pattern baldness. With the exception of hair transplant surgery, there’s no way to instantly restore a receding hairline or other consequences of pattern hair loss.

Realistically, you can expect the DHT blockers supported by high-quality scientific evidence to help slow down or stop male pattern baldness. 

The ones without scientific support? You’re probably better off skipping.

DHT blockers come in two main forms. Some stop DHT from being produced by blocking the effects of 5-alpha reductase enzymes. Others block the effects of DHT at the hair follicles.

Of the prescription DHT blockers currently on the market, finasteride is arguably the best. It's approved by the Food and Drug Administration (FDA) for treating hair loss and backed up by plenty of research. It's even endorsed by the American Academy of Dermatology.

Over-the-counter DHT blockers are typically shampoos and other topical hair care products. These work differently and aren’t as rigorously studied as finasteride.  

Read on to learn more about these options.

Finasteride

Also known by the brand name Propecia, finasteride belongs to a class of drugs called 5-alpha-reductase inhibitors. It works by reducing the effects of the 5α-reductase enzyme, which is responsible for the conversion of testosterone into DHT. 

By blocking DHT production directly at the source, finasteride drastically reduces the levels of DHT in your body. Research shows that it can lower the amount of DHT by as much as 70 percent.

Not only can finasteride slow down male pattern hair loss — it might also promote the growth of new hair. A recent study from Japan found that more than 91 percent of men who used the medication to treat male pattern baldness experienced some hair regrowth.

DHT-Blocking Shampoos 

While finasteride works by reducing DHT levels inside the body, other DHT-blocking agents work locally on the scalps.

Available over the counter, DHT-blocking shampoos contain active ingredients that reduce the effects of DHT on your scalp and prevent DHT from damaging hair follicles.

But even though certain DHT-blocking shampoos might slow down hair loss, there’s not nearly as much scientific evidence to support their benefits as there is for oral finasteride. 

Look for the following ingredients when you’re comparing hair loss shampoos:

  • Ketoconazole. An antifungal medication that’s usually used to treat skin infections like athlete's foot, ketoconazole also inhibits 5α-reductase — the enzyme that converts testosterone into DHT. Research suggests that ketoconazole shampoo can increase hair density and stimulate hair follicles to enter the anagen phase of the hair growth cycle.  

  • Saw palmetto. Saw palmetto is a natural DHT blocker that’s extracted from a palm plant called Serenoa repens. Some research has found that saw palmetto — both in the form of oral supplements and topical applications — can slow down male pattern hair loss. You can find saw palmetto in our hair thickening shampoo, which is formulated to promote volume and moisture.

  • Pumpkin seed oil. Pumpkin seed oil has also been linked to hair growth. Some research suggests that pumpkin seed oil supplements can increase hair growth in men with male pattern baldness. However, the research on pumpkin seed oil for hair loss is fairly thin, so it’s best to use it along with another product.

  • Green tea. That’s right. You can add better hair health to the long list of green tea benefits. Green tea moisturizes and smooths hair. And since it has antioxidant properties, green tea can increase blood flow, which benefits hair follicles. Some research suggests that green tea could be a natural DHT blocker, decreasing DHT formation.

In general, it’s best to use hair loss shampoo while also taking finasteride, rather than using a shampoo on its own. 

Our guide to DHT-blocking shampoos explains more about how a hair loss shampoo can fit into your hair care routine for optimal results. 

DHT blockers are safe and effective for most men. However, some DHT-blocking medications may cause certain side effects — including sexual ones. 

The most common side effects of finasteride include:

But these side effects only affect a small percentage of men who use finasteride. For example, data from clinical trials shows that erectile dysfunction — the most publicized side effect of finasteride — only occurred in 1.3 percent of men who used it at the standard 1mg dose. 

Side effects from DHT blockers used in hair loss prevention shampoos are also uncommon. Some ingredients may cause irritation, dry skin, itchy skin or other similarly minor effects. 

If you experience any side effects while using finasteride or a topical DHT blocker, it’s important to let your healthcare provider know. 

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Before/after images shared by customers who have purchased varying products, including prescription based products. Prescription products require an online consultation with a healthcare provider who will determine if a prescription is appropriate. These customers’ results have not been independently verified. Individual results will vary. Customers were given free product.

Finasteride, for all its benefits, is not a total cure-all. 

Although DHT-blocking medication can be a game-changer for your hairline, there’s so much more you can do to promote healthy hair.  

In addition to the DHT blockers listed above, consider using the following treatments as part of your hair loss prevention routine:

Minoxidil

Along with finasteride, minoxidil is probably the most well-known hair loss treatment. It can be taken topically or orally, and its topical formulations are sold over-the-counter. 

Minoxidil works by increasing blood flow to the scalp, moving hairs into the anagen phase of the hair growth cycle. This stimulates hair growth.  

Now we bet you’re asking yourself, does minoxidil block DHT? Nope — minoxidil is not a DHT blocker. That’s why it can treat types of hair loss that aren’t related to DHT, such as telogen effluvium

But it’s still one of the most effective medications available for treating male pattern baldness, especially when it’s used in combination with finasteride.

In a study published in the journal Dermatologic Therapy, researchers found that 94.1 percent of men with androgenetic hair loss who used topical minoxidil and finasteride together saw improvements in their hair.

We offer minoxidil solution and minoxidil foam online. You can also try our topical finasteride and minoxidil spray, which combines both active ingredients in one convenient hair care product.

Biotin Supplements

Your body needs nutrients in order to grow hair. One way to ensure that you have all the nutrients you need? Take a high quality supplement.

Biotin, or vitamin B7, is a water-soluble vitamin found in certain foods. It’s also a popular dietary supplement that can help build thick hair, strong nails and healthy skin. 

As with many other vitamins, research is mixed overall on the effectiveness of biotin as a hair growth supplement. However, some studies of supplements containing biotin suggest that they may offer benefits — especially for someone who's biotin-deficient. 

Hair loss treatments, delivered

DHT is a pretty important hormone when you’re growing up — but as you age, it can become your hairline’s worst enemy. Since DHT is the main cause of androgenetic or androgenic alopecia, a DHT blocker can be the best way to treat pattern baldness.

Just keep in mind:

  • Not all DHT blockers are equally effective. Finasteride is the most well-known science-backed DHT blocker. Natural DHT blockers, like saw palmetto and pumpkin seed oil, aren’t as rigorously studied as finasteride. 

  • You can combine treatments. Wanna give your follicles some extra support? Finasteride can be combined with DHT-blocking hair loss shampoos as well as other hair loss treatments, like minoxidil and biotin supplements. 

  • Act fast. Male pattern hair loss doesn’t stop on its own, and sadly, there’s a high chance your hair will never return to its former glory. The best way to prevent further damage is to get treatment ASAP.

Wanna learn more about slowing down male pattern hair loss? Check out our full guide to finasteride for men. While you’re at it, read our hair care tips for men for help keeping your hair as healthy and full as possible.

But your best port of call is to get medical advice from an expert. We can help you set up an online consultation with a healthcare professional who can explain your treatment options and, if appropriate, prescribe a DHT blocker like finasteride.

18 Sources

  1. Kinter, K.J. & Anekar, A.A. (2021, March 13). Biochemistry, Dihydrotestosterone. StatPearls. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK557634/
  2. Ho, C.H., Sood, T. & Zito, P.M. (2021, November 15). Androgenetic Alopecia. StatPearls. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK430924/
  3. Hoover, E., Alhajj, M. & Flores, J.L. (2021, July 26). ​​Physiology, Hair. StatPearls. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK499948/
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  8. Yanagisawa, M., et al. (2019, January). Long-term (10-year) efficacy of finasteride in 523 Japanese men with androgenetic alopecia. Clinical Research and Trials. 5, 1-5. Retrieved from https://www.researchgate.net/publication/337105943_Long-term_10-year_efficacy_of_finasteride_in_523_Japanese_men_with_androgenetic_alopecia
  9. Rafi, A.W. & Katz, R.M. (2011). Pilot Study of 15 Patients Receiving a New Treatment Regimen for Androgenic Alopecia: The Effects of Atopy on AGA. ISRN Dermatology. 241953. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3262531/
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  12. Rossi, A., et al. (2012, October-December). Comparitive effectiveness of finasteride vs Serenoa repens in male androgenetic alopecia: a two-year study. International Journal of Immunopathology and Pharmacology. 25 (4), 1167-73. Retrieved from https://pubmed.ncbi.nlm.nih.gov/23298508/
  13. Hong, H., Kim, C.-S. & Maeng, S. (2009). Effects of pumpkin seed oil and saw palmetto oil in Korean men with symptomatic benign prostatic hyperplasia. 3 (4), 323–327. Retrieved from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2809240/
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  15. Badri, T., Nessel, T.A. & Kumar, D.D. (2021, December 19). Minoxidil. StatPearls. Retrieved from https://www.ncbi.nlm.nih.gov/books/NBK482378/
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  18. PROPECIA® (finasteride) tablets for oral use. (2012, April). Retrieved from https://www.accessdata.fda.gov/drugsatfda_docs/label/2012/020788s020s021s023lbl.pdf
Editorial Standards

Hims & Hers has strict sourcing guidelines to ensure our content is accurate and current. We rely on peer-reviewed studies, academic research institutions, and medical associations. We strive to use primary sources and refrain from using tertiary references. See a mistake? Let us know at [email protected]!

This article is for informational purposes only and does not constitute medical advice. The information contained herein is not a substitute for and should never be relied upon for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment. Learn more about our editorial standards here.

Knox Beasley, MD

Dr. Knox Beasley is a board certified dermatologist specializing in hair loss. He completed his undergraduate studies at the United States Military Academy at West Point, NY, and subsequently attended medical school at Tulane University School of Medicine in New Orleans, LA. 

Dr. Beasley first began doing telemedicine during his dermatology residency in 2013 with the military, helping to diagnose dermatologic conditions in soldiers all over the world. 

Dr. Beasley is board certified by the American Board of Dermatology, and is a Fellow of the American Academy of Dermatology.

Originally from Nashville, TN, Dr. Beasley currently lives in North Carolina and enjoys spending time outdoors (with sunscreen of course) with his wife and two children in his spare time. 

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  • Dermatology Residency. San Antonio Uniformed Services Health Education Consortium

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