Medically reviewed by Kristin Hall, FNP
Written by Our Editorial Team
Last updated 8/16/2021
If you’re starting to lose your hair, you may have started to look at your options for stopping hair loss and stimulating growth, including DHT blocking shampoos.
There are several anti-DHT shampoo ingredients that are proven to have some effect on scalp DHT levels.
One of these ingredients is ketoconazole, which is linked to disruption of the DHT pathway in the scalp.
One of the most common questions we receive is whether or not DHT-blocking shampoos are actually effective at preventing hair loss.
Below, we’ll cover everything you need to know about DHT blocking shampoos, from the most common DHT blocking shampoo ingredients and their effectiveness as hair loss treatments to the best ways to use a hair loss prevention shampoo as part of your hair care routine.
We’ll also talk about some of the most widely used ingredients that don’t do much to block DHT or prevent hair loss, and how you can separate these from the few active ingredients that really work.
Before we get into the specifics of DHT blocking shampoos, it’s important to explain what DHT actually is.
DHT stands for dihydrotestosterone. It’s an androgen hormone that’s produced as a byproduct of testosterone.
The specific enzyme that’s responsible for converting testosterone into DHT is referred to as 5 alpha-reductase, or 5AR.
As a hormone, DHT plays a key role in several biological processes during your childhood and puberty.
Before you’re born, DHT is responsible for developing your penis, scrotum and prostate. During puberty, DHT plays a major role in the development of male secondary sex characteristics, such as your facial hair and body hair.
After puberty, DHT doesn’t play such a major role in your physical development. However, it still remains active in your body.
If you’re genetically predisposed to male pattern baldness, DHT can bind to receptors located in your scalp and promote a process called miniaturization, in which your hair follicles slowly shrink and stop producing new hairs.
Miniaturization affects men and women. However, due to the much higher level of androgens in men, the effects of DHT on hair are much more visible and obvious.
Over time, as your hair follicles shrink and become inactive from DHT exposure, it can result in the classic receding hairline or bald patch that’s associated with male pattern baldness.
DHT blocking shampoos are exactly what they sound like -- shampoos that are formulated with ingredients that block the effects of DHT on your scalp.
Most treatments for male pattern baldness work by blocking DHT, either systemically or at your scalp specifically.
For example, the hair loss medication finasteride works by inhibiting 5 alpha-reductase, which reduces your body’s ability to convert testosterone to DHT.
DHT blocking shampoos are designed to have a similar effect, but at the scalp level. Instead of blocking DHT throughout your body, the ingredients in DHT blocking shampoos are designed to lower DHT activity where it matters most for hair loss -- at the hair follicle level.
The market for hair loss prevention shampoos has surged over the last few decades, with new shampoos popping up left and right boasting a range of natural and pharmaceutical ingredients that are designed to block DHT at the scalp and prevent hair loss.
Many of these shampoos are made with exotic oils, plant extracts and other natural ingredients that promise to stop hair loss.
While there may be some potential value in DHT blocking shampoos, some of the claims made by anti-hair loss shampoo brands deserve healthy skepticism.
When it comes to hair loss shampoos, active ingredients are far more important than beautiful packaging or brand names.
Because of this, you’ll want to check the list of ingredients before you buy any shampoo that’s designed to block DHT.
Most shampoos contain only a few active ingredients -- usually chemicals or natural extracts -- that have an active, measurable effect.
The rest of the ingredients used in most shampoos are used to create the shampoo’s scent, feel and texture, not to treat hair loss.
While these can make a shampoo much nicer to use, it’s the DHT-blocking ingredients that do the actual work of presenting hair loss.
Currently, research suggests that the following active ingredients may have an effect on scalp DHT levels and hair growth.
Ketoconazole is an antifungal ingredient. It’s used to treat tinea infections, including ringworm, athlete’s foot and jock itch.
As a shampoo ingredient, it’s often used to manage flaking, scaling and itching that can occur due to dandruff.
You can find ketoconazole as an active ingredient in many DHT-blocking shampoos, although it isn’t used in every formula.
Although it’s best known for its antifungal effects, DHT is also linked to disruption of the process by which DHT is synthesized in the scalp and hair follicles.
Some research has found that ketoconazole shampoo can improve hair density and the size of hair follicles in the anagen (growth) phase of the hair growth cycle.
With this said, it’s important to note that research into the effects of ketoconazole on scalp DHT levels is very limited, with no large-scale studies available.
Our guide to ketoconazole and hair loss goes into greater detail about the most recent research on ketoconazole as an active ingredient in hair loss products.
Saw palmetto is a naturally-occurring ingredient that’s extracted from the Serenoa repens plant, a small palm that grows throughout the Southeastern United States.
You can find saw palmetto as an active ingredient in many hair loss shampoos. It’s also sold as a dietary supplement, usually in capsule form.
Although study data on saw palmetto as a hair loss treatment is limited, some researchers think that saw palmetto may work by inhibiting the conversion of testosterone to DHT.
A few studies have found that saw palmetto promotes hair growth. In one study published in the International Journal of Immunopathology and Pharmacology, researchers compared the effects of a saw palmetto supplement with the hair loss medication finasteride.
They found that finasteride improved hair growth in 68 percent of men affected by androgenetic alopecia (male pattern baldness), while saw palmetto produced improvements in 38 percent.
A different study published in the journal Urology found that a saw palmetto supplement lowered DHT levels by 32 percent in men with benign prostatic hyperplasia (BPH).
It’s important to note that this study measured DHT levels in the men’s prostate tissue, not in the hair follicles or scalp.
Our guide to saw palmetto for preventing hair loss looks at the latest research on saw palmetto as a treatment for male pattern baldness in more detail.
Pumpkin seed is one of several natural ingredients that’s been researched as a treatment option for hair loss in men.
Although human research is limited, animal studies have found that pumpkin seed oil may have a protective effect on DHT-sensitive prostate tissue.
A study of men with benign prostatic hyperplasia also found that a combination of pumpkin seed oil and saw palmetto oil improved several symptoms of prostate enlargement.
Since BPH is largely caused by the effects of DHT, these findings suggest that pumpkin seed oil may have anti-DHT effects in the body.
Other research has found that pumpkin seed oil can improve hair growth. In a study published in the journal Evidence-Based Complementary and Alternative Medicine, researchers found that a pumpkin seed oil supplement produced a 40 percent increase in hair count in balding men.
It’s worth noting that these studies used an oral pumpkin seed oil supplement, not a shampoo or other topical product.
Currently, we don’t know if topical pumpkin seed oil has the same benefits for thinning hair.
We’ve discussed the research on pumpkin seed oil in more detail in our guide to pumpkin seed oil for hair growth.
Although blocking DHT is an important part of treating and preventing hair loss, it’s not the only step in the process.
Many of the ingredients used in DHT blocking shampoos don’t necessarily block DHT. However, they may offer other benefits, such as the ability to increase blood flow to your scalp or promote hair growth in other ways.
Many hair loss shampoos are formulated using vitamins, such as vitamins A, B12, C and D. As we’ve covered in our guide to essential vitamins for healthy hair growth, many of these vitamins play important roles in the hair growth process.
Although these vitamins don’t block DHT, they often help to create an environment that makes hair growth more likely.
There are several other natural ingredients used in hair loss shampoos that may help to boost hair regrowth without much impact on DHT levels.
For example, rosemary oil has been studied as a natural hair growth ingredient, with research showing that it can produce increases in hair growth similar to those achieved by the hair loss medication minoxidil, often with fewer adverse effects.
However, there’s currently very little research on rosemary oil’s effects on DHT levels, whether in the scalp or systematically.
Currently, research on these ingredients is ongoing, with some ingredients showing promising effects on hair growth.
However, there’s currently no evidence that these ingredients have any impact on DHT levels.
Our guide to natural oils for hair growth lists other natural ingredients that may offer benefits for healthier hair growth.
Considering buying a hair growth shampoo? Here are some factors to keep in mind when you’re comparing shampoos designed to block DHT and prevent hair loss:
Read the ingredients list before you buy. Not all hair loss prevention shampoos make use of active ingredients, making it important to check the ingredients list before you buy anything. Look for one or several of the ingredients mentioned above to ensure that the shampoo is effective and worth purchasing.
See an ambitious claim? Look for evidence. Many shampoo brands make big claims about their shampoo’s abilities to prevent shedding, promote hair growth and add extra volume to your hair, all without providing any real proof. If you see a shampoo that makes big promises, put in some time to research and see if the active ingredients are truly effective.
Stick with proven, effective ingredients. Almost all of the ingredients used in hair loss prevention shampoos offer some benefits for your hair, whether it’s improved texture or a pleasant scent. However, it’s the active ingredients that do the real work.
Be careful of ingredients that cause irritation. Some ingredients used in shampoos may cause irritation. For example, although research on their effects is mixed, a small number of people report skin issues with ingredients such as sulfates and parabens. If you have sensitive skin, try to look for sulfate-free shampoo. Our guide to sulfates in shampoo talks more about the effects of sulfates, as well as steps that you can take to avoid them if you have sensitive skin.
Don’t associate cost with effectiveness. Like with many other skin and hair products, a high price tag doesn’t necessarily mean that a shampoo is effective at preventing hair loss or promoting hair growth. When you’re comparing shampoos, look for active ingredients, not a high price tag. The best DHT blocking shampoos are usually affordable, while a lot of expensive shampoos fail to live up to the hype.
Use a DHT shampoo with hair loss medication. While the right shampoo can help to prevent hair loss by itself, you’ll get the best results by combining it with science-based hair loss treatments such as finasteride and minoxidil. These medications work to block DHT and promote hair growth. We’ve gone into more detail about how they work and their effects in the section below.
Check customer reviews before you buy. Like other hair care products, DHT blocker shampoos can vary in quality. If you’re shopping online, make sure to read reviews from previous customers before committing to a specific product.
Don’t forget to use a conditioner. Conditioner helps to strengthen your hair and give it extra shine and moisture. Applying conditioner is particularly important if you have a hair type that gets dry or damaged easily. Our Thick Fix Conditioner is formulated to support healthy hair growth while helping your hair appear thicker and fuller.
Have realistic expectations. Although many of the ingredients used in DHT blocking shampoos are supported by scientific evidence, none should be viewed as alternatives to or replacements for FDA-approved hair loss medications. As such, it’s important to have realistic expectations, especially if you use a DHT blocker shampoo without medication. While the right shampoo may help to stimulate hair growth, it’s unlikely to completely turn around hair loss on its own.
While a good quality DHT blocking shampoo can have a positive impact on your hair’s strength, health and thickness, it’s not the only product that you should use if you’re starting to lose hair.
Currently, the most effective products for treating hair loss are FDA-approved medications, such as minoxidil and finasteride.
Minoxidil is a topical medication that you apply directly to your scalp. It’s available as a liquid or foam.
Minoxidil works by increasing blood flow to your scalp and moving your hair follicles into the anagen, or growth, phase of the hair growth cycle.
You may have heard of minoxidil as Rogaine®. Today, minoxidil is sold under its original brand name and as a generic medication.
Used consistently, minoxidil can improve thickness and density in areas of your scalp affected by male pattern baldness.
Finasteride is an oral hair loss medication. It works by inhibiting the 5 alpha-reductase enzyme throughout your body.
Currently, finasteride is the most effective FDA-approved medication for blocking DHT. In fact, research shows that a typical dose of finasteride can lower serum DHT levels (the amount of DHT in your blood) by more than 70 percent.
Like minoxidil, finasteride can produce real, noticeable improvements in your hair when used consistently.
We offer finasteride on its own, and with minoxidil and other products in our Hair Power Pack, following a consultation with a licensed healthcare provider who will determine if a prescription is appropriate.
Used as part of a well-rounded, science-based hair care routine, a DHT blocking shampoo can help you to treat male pattern baldness and even regrow hair in areas of your scalp with visible thinning.
When you’re comparing anti-DHT shampoos, look for products that use proven ingredients that can prevent buildup and promote the growth of healthier, thicker hair.
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