DHT plays an important role in hair loss.
We know from studies such as this and this that when men lack DHT due to castration in early life they never go bald.
Those same men when later injected with testosterone begin to show early signs of hair loss.
DHT is created from testosterone via enzygmatic conversion by 5-alpha-reducatse. So by castrating the men they never produced testosterone and hence never produced DHT.
Blocking DHT topically (on the scalp) rather than systematically (throughout the body) reduces your chances of adverse side effects that are associated with DHT blocking because DHT is reduced only in the scalp.
By blocking DHT throughout the body you have a much higher risk of affecting other parts of the body such as our sex organs.
DHT is a natural and normal hormone, so by blocking it we do risk side effects. That’s why it’s lower risk just to block it locally.
Unfortunately though, due to a number of complex reasons (primarily calcification and fibrosis) even the systematic blocking of DHT won’t completely reverse hair loss if it has already taken place. This is why men on high doses of the DHT blocker finasteride rarely regrow much hair at all. (We would expect them to regrow all their hair if DHT was the only factor.)
Since almost everyone uses a shampoo at least once a week, it would make sense to use a shampoo that has some sort of ability to topically reduce DHT with the aim to allow the hairs to grow better.
In theory this makes sense, although in practice blocking DHT topically with the aim to regrow hair is certainly not the most effective way to do so.
Essentially, it may help, however the difference is unlikely to be very obvious.
In this article you’ll learn about the very best options when it comes to topically blocking DHT with a shampoo or other option.
How DHT Affects Your Hair
DHT is made from the naturally-occurring hormone, testosterone. DHT is formed when an enzyme known as 5-alpha-reductase, or 5AR, converts testosterone into di-hydrotestosterone (2).
Lowering testosterone levels to control DHT is not an option. Whether you’re male or female, your body needs a certain amount of testosterone to function properly, and you don’t want to upset the natural balance of your hormone levels (3).
Men and women who suffer from male pattern baldness don’t necessarily have more DHT; instead, they have a sensitivity to it — one that causes their follicles to miniaturize and weaken (4).
So, although one approach to controlling DHT would be to control the amount of 5AR circulating in your body or to slow the action of the enzyme, a better option might be to remove DHT from your scalp altogether.
This can help your hair grow stronger and thicker (5).
However, in order to reduce your scalp’s DHT levels, you’ll need to make sure there’s no build-up of waste products or sebum on your scalp.
This excess debris, called a plaque, is quite common in people suffering with androgenic alopecia, and can block hair follicles and weaken hair growth.
Preparing the Scalp for a DHT-Blocking Shampoo
Part of preparing your scalp for a DHT-blocking shampoo is removing the plaque and debris that can interfere with the shampoo’s efficacy.
In order to remove DHT from your scalp, you must first remove the waste products that have built up on the epidermis.
Without cleaning this debris, new hairs will be less likely to be able to push through, making it more difficult to grow strong hair.
By cleansing your scalp, you’ll be removing:
- Embedded sebum
- Dead skin
- Cosmetic products
These substances mix together on your scalp and become a plaque that prevents hair growth and causes miniaturization of existing hair follicles.
If you are bald or your hair is thinning, you may notice the skin of your scalp becoming shiny. That shininess is evidence of a plaque of debris.
The plaque also contains DHT crystals that are secreted through the epidermis, creating a perpetually inhospitable environment for hair growth.
Removing this plaque is the object of exfoliation, a dermatological technique proven to remove dead cell build-up and waste by-products (6).
In fact, certain exfoliants have been used effectively to remove hardened sebum and cleanse the skin of your scalp (7).
There are several techniques you can use to effectively exfoliate the skin of your scalp to remove debris. They range from gentle acids to natural products that are safe enough to eat.
Any of these substances is safe for the skin of your scalp will not damage the roots of your hair. Hair follicles grow at a deeper layer that is unaffected by these types of topical solutions.
Salicylic acid is a gentle acid that’s miscible, or able to mix, with lipids like the sebaceous and epidermal liquids that surround your hair follicles (8).
In fact, studies show that salicylic acid can help shed dead cell buildup without affecting the normal functioning of your scalp’s cells (9).
Along with this, salicylic acid can stimulate the renewal and growth of new cells without damaging, or in any way affecting, nearby follicular cells. Being part of the compound that forms aspirin, it also provides anti-inflammatory benefits to your scalp and hair follicles (10)(11).
Still other studies show salicylic acid to have anti-fungal and anesthetic qualities, both of which can be useful in treating androgenetic alopecia (12).
To use salicylic acid as a scalp peel, shampoo and rinse your hair thoroughly, then apply coconut oil to your scalp to moisturize and protect the scalp from the drying effects of the acid.
After 30 minutes, take an eye dropper and apply a solution of 15% salicylic acid to your scalp one section at a time. Be sure to cover areas that are thinning or have dandruff.
Leave the acid on your scalp for 10 minutes, then rinse well. If there is any salicylic acid left behind, just peel away.
This peel is safe enough for monthly use to keep your scalp free of plaque.
Natural Scalp Exfoliators
By far, the most effective way to remove the epidermis plaque is to use a homemade scalp exfoliator to gently and naturally remove the plaque making the method more effective.
There are several safe, effective ingredients that can be used to remove plaque build-up on your scalp.
This natural and minimally-processed salt is antibacterial, and it can draw bacteria and mites from the pores of your scalp (13).
It is gently abrasive to help loosen the build-up of plaque without damaging your skin.
The salt also balances excess acidity in the scalp by neutralizing acids that may have formed and would otherwise be damaging the hair follicles.
Activated Powdered Charcoal
Activated charcoal is created by burning wood, coconut shells, or other debris — basically, any source of carbon.
The intense applied heat removes all oxygen to “activate” the charcoal with gases. This process then fills the final product with millions of tiny pores.
Activated powdered charcoal is a well-known cleansing agent because of its ability to adsorb toxins. Adsorption is different from absorption (14).
The tiny pores in charcoal cause the toxins to stick in their crevices and edges, or adsorb. This ability to draw out toxins not only aids in removing grease and impurities from your scalp, but helps with wound healing.
If you have any irritation on your scalp, charcoal can help soothe the inflammation and help it heal (15).
Activated charcoal, besides helping to remove impurities, is fairly ‘rough,’ meaning it can help to gently exfoliate the scalp by rubbing against any plaque and gently removing it (16).
The charcoal also helps to neutralize molds which can grow on the embedded plaque (17).
Lemon juice is a weak tricarboxylic acid that can break down oils, dead skin cells, and leftover cosmetics attached to the scalp (18).
The citric acid contained in the lemon juice is a powerful, but gentle, cleanser that removes flaky skin and cleans the pores without damaging hair or scalp.
Studies show that lemon oil also has anti-inflammatory properties. These can help soothe any inflammation or scalp irritation present (19).
The active ingredient in ginger juice, 6-gingerol, has amazing therapeutic properties — including the boosting of blood circulation, which is essential for scalp health (20).
In addition, a study published by Xu Y, entitled Dermatology in Traditional Chinese Medicine (Donica Publishing Ltd.; 2004) successfully used an herbal mixture including ginger root to treat androgenetic alopecia.
Hyaluronic acid (HA) is important in providing an environment for the synthesis of extracellular matrix molecules and in encouraging healthy epidermal cell interaction with the surrounding environment (21)(22).
Hyaluronic acid modulates allergic reactions and boosts cellular immunity. It’s also crucial for tissue regeneration and health cell turnover (23).
Importantly, it can hold a large amount of moisture for hydrated skin. As we age, we lose HA in our skin, contributing to dry skin and wrinkles.
Emu oil is a potent anti-inflammatory with anti-fungal capabilities. It is clinically effective in improving scalp conditions such as seborrheic dermatitis, and it can be a useful adjunct in preparing your scalp for a topical DHT blocker (26).
In addition, it’s well known that alpha-linoleic and gamma-linoleic fatty acids help inhibit 5-alpha reductase from making DHT.
Oleic acid is also a known 5-alpha-reducatase inhibitor, but in most forms, like flaxseed oil, its large molecules can’t penetrate the skin to reach the follicle (27).
Emu oil consists of primarily oleic acid with about 20 percent linoleic acid and a small percentage of linolenic acid. In addition, it’s an effective anti-inflammatory with good skin penetration (28)(29).
Using a DHT-Blocking Shampoo
After you’ve properly cleansed your scalp, you’re ready to begin using a DHT-blocking shampoo.
There are several ingredients that are known to contribute to the blocking of DHT in hair follicles. At least one of these should be included in any shampoo formula — homemade or store-bought.
Choosing a Shampoo with DHT-Blocking Ingredients
The most important part of using a DHT-blocking shampoo is to choose one that has one or more of the following proven ingredients.
1. Rosemary Oil and Extract
One of the most widely studied essential oils, rosemary oil is a versatile essential oil with proven therapeutic health benefits. In the past, it’s been recorded to act as an:
While all of these properties can contribute to healthy hair growth, the most exciting benefit for hair loss sufferers is rosemary oil’s proven ability to inhibit 5AR.
In 2013, researchers from Japan used mice to show that topical application of Rosmarinus officinalis leaf extract (RO-ext) could be used to induce hair growth.
The first part of the study showed that mice previously treated with testosterone, which interrupted hair regrowth, saw improved hair growth once treated with RO-ext 2mg/day:
The researchers took it one step further, though. They also wanted to see whether RO-ext had any anti-androgenetic activity. To do this, they compared various concentrations of the extract to finasteride:
The results show the two highest doses – 200 and 500 µg/mL – had inhibitory activity of 82.4% and 94.6%, respectively. In comparison, finasteride only showed inhibitory activity of 81.9% in the same study.
According to researchers, “[t]hese results suggest that [RO-ext] inhibit[s] the binding of dihydrotestosterone to androgen receptors.”
Another study comparing rosemary oil to minoxidil 2% showed that rosemary oil performed as well as the minoxidil on human participants, without causing any side effects (34).
While this study didn’t measure anti-androgenetic effects specifically, it did show that rosemary helped increase hair counts when used topically by men experiencing AGA.
2. Saw Palmetto
Serenoa repens, or saw palmetto, has long been used medicinally by the Seminole Indians of Florida. It is well tolerated by most individuals and appears to have few side effects other than mild headache (35).
There are several ways that saw palmetto can be used to minimize hair loss (36):
- It blocks 5AR in a way similar to the prescription drug finasteride, but without side effects.
- It decreases the uptake of DHT by hair follicles.
- It decreased the binding of DHT to androgen receptors.
The first study, undertaken in 2012, compared the effectiveness of finasteride to saw palmetto in treating AGA. Although this was a study that concentrated on its oral, not topical, benefits, it still sheds light on saw palmetto’s use as a DHT blocker. (39)
The study consisted of 100 men diagnosed with mild to moderate AGA who were split into two groups.
One group received saw palmetto 320 mg every day for 24 months and the other received finasteride 1mg every day for 24 months.
Global photos were taken at baseline (T0) and the end of the study (T24), and a predetermined scoring index was used to measure change.
Ultimately, 38 of the saw palmetto recipients saw hair growth compared to 68 finasteride users. However, that still amounts to more than half of the participants in the saw palmetto group seeing results.
Importantly, a more recent study explored the topical benefits of saw palmetto. (40)
In 2016, researchers applied saw palmetto to the shaved flank areas of Syrian hamsters along with either DHT or testosterone to determine whether saw palmetto could be helpful in regrowing hair.
The results of this study showed that saw palmetto indirectly blocked DHT by inhibiting 5AR.
The hamsters that received saw palmetto plus testosterone showed reduced pigmentation – a sign of the plant’s androgenic activities – than when it was combined with DHT.
For humans suffering from thinning hair, less 5AR equates to less DHT, which can mean less inflammation and less hair loss.
3. Reishi Mushroom
In a 2005 study of more than 19 mushrooms species, reishi mushroom (G. lucidum) was able to inhibit between 70 and 80 percent of the activities of 5AR. (41)
The study was split into two parts. The first used ethanol extracts of the mushroom species which were then added to suspensions containing rat liver and prostate microsomes. This shed light on the percentage of inhibitory activity, as shown in the study.
Researchers were also interested in reishi’s ability to inhibit testosterone. Interestingly, the lower concentration (1.5 mg/kg) of G. lucidum was more effective than the higher concentration (15 mg/kg).
Researchers stated, “[t]he anti-androgenic activity of Ganoderma lucidum is an important biological activity for use with BHP patients.”
This testosterone-inhibiting activity, along with saw palmetto’s ability to inhibit 5AR, has far-ranging implications for men and women with AGA.
4. Stinging Nettle
Stinging nettle is aptly named for the mild stinging sensations that often preclude people from handling the plant. In addition, however, research on its anti-androgenic effects has proven that it may be a potent topical DHT blocker.
A study of rats with Benign Prostatic Hyperplasia (BPH) treated with stinging nettle was undertaken in 2011. The rats’ prostate weight was measured throughout the study to determine the anti-androgenic effects of the stinging nettle (42).
Since BPH involves the enlargement of the prostate and is believed to be caused by high DHT levels, researchers looked for lowered prostate size to indicate a reduction in DHT and signal anti-androgenic activities (43).
Since stinging nettle successfully reduced rat prostate size, it is potentially useful in the minimizing of DHT on the scalps of men and women suffering from AGA.
5. Pumpkin Seed Oil
Pumpkin seed oil (PSO), extracted from the Curcubita pepo seed, has been shown to reduce prostate size in rats with testosterone-induced BPH (44).
As discussed above, reduced prostate weights in rats with BPH are attributed to anti-androgenetic activities, in this case, the activity of the pumpkin seed oil.
A randomized, double-blind study conducted in 2014 that studied pumpkin seed oil for use specifically to treat AGA in 76 human subjects found that PSO outperformed the placebo at both 12- and 24-week assessments (45).
During the final assessment at 24 weeks, investigators found that hair loss had stopped in 51.4% (19/37) of the participants receiving PSO treatment and 44.1% (17/37) were rated as slightly or moderately improved.
In the control group, 64.1% (25/39) of the participants showed no further hair loss, while only 7.7% (3/39) saw slight or moderate improvement.
While the study was small, with only 76 total participants, it could be indicative of pumpkin seed oil’s ability to inhibit 5AR, thus blocking DHT.
How to Shampoo Properly
It might be tempting to use a DHT-blocking shampoo every day, thinking that it will provide more protection to your follicles, but you would be wrong.
Shampooing every day can strip your hair of natural oils and contribute to dry, flaky scalp and even more oil production.
Instead, aim to shampoo twice a week — more after heavy sweating.
Some DHT-blocking shampoos don’t lather a lot — and that’s okay. Just massage them into your scalp and let them sit for a few minutes to let your follicles soak up the formula, then rinse well with warm water.
DHT can have a real impact on the health and strength of your hair.
Over time, shampoos, hair products, natural oils, and environmental pollutants can build up on your scalp, blocking follicles and causing a build-up of DHT-promoting plaque.
Cleansing the scalp with natural exfoliants is a great way to remove this plaque and prepare your scalp for a high-quality DHT-blocking shampoo.
DHT-blocking shampoos can be created at home or purchased from a reputable source, but they should contain at least one of the following proven DHT blockers for best results:
- Rosemary essential oil
- Saw palmetto
- Stinging nettle
- Reishi mushroom
- Pumpkin seed oil
Once you’ve chosen your shampoo, make sure you don’t overdo it — washing once or twice a week is plenty. Overwashing can damage hair and scalp and lead to itching, peeling, or oily buildup.
While a DHT-blocking shampoo might not give you a full head of hair on its own, it’s an important part of a sensible hair-regrowth program.