There are many causes of hair loss, but the most common is Androgenetic Alopecia (AGA) and, more specifically, sensitivity to DHT as a result (1).
But there is hope for treatment. One such option? Natural DHT blockers.
In this comprehensive guide, you’ll learn of the 12 best natural DHT blockers you can use to stop hair loss and perhaps even reverse it. But first, let’s take a look at the role DHT plays in hair loss and why blocking it can help.
NOTE: ‘Natural’ can be a rather ambiguous word, which is why it’s important to clarify its meaning as used throughout this article. Natural refers to any plant or food products which have not been processed, or synthesized in a laboratory. These can include seeds, leaves, stems, oils, and extracts.
What Are DHT Blockers?
DHT is an androstanolone, an androgen sex steroid and hormone that is found in both sexes (4). It is produced from the interaction between 5-alpha-reductase and Total Testosterone TT.
This ‘type’ of testosterone is produced mainly in the testes, but testosterone can be found throughout the body including the prostate and hair follicles (5). The result of this interaction is two by-products (6):
- Free testosterone (fT)
- Dihydrotestosterone (DHT)
Interestingly, oxygen also plays a role in testosterone’s conversion to DHT (4). Free testosterone – one of the byproducts of 5AR and testosterone – is able to travel throughout the body – this includes to the scalp and hair follicles (7).
With fT now in the follicles where 5AR is also present, it has the opportunity to be converted to DHT (8).
However, this requires a certain set of circumstances. Foremost, the amount of oxygen will determine whether that fT becomes DHT (which requires less oxygen), or estradiol (as it requires more oxygen) (9).
So, in short, decreased oxygen levels which are common in the scalps of AGA sufferers can mean an increase in DHT production as estradiol production is slowed.
This is important because not only does the presence of DHT trigger hair loss in AGA sufferers, but the presence of estradiol has been shown to promote hair regrowth (10).
DHT blockers, then, are substances or ingredients that lower the levels of DHT within the body and, thereby, reduce follicle miniaturization (2).
One of the most common DHT blockers is finasteride, which inhibits the activities of 5AR (11). However, there are natural ingredients which have also been proven to work in the same vein.
Is Finasteride a Viable Option?
Why should you choose natural ingredients over one of the most well-known DHT blockers on the market?
The main reason is side effects (12).
These include headache and dizziness, anxiety, depression, and swelling of the hands and feet (13). Though, the more worrying side effects are sexual in nature.
- Loss of libido
- Difficulty getting/maintaining an erection
- Loss of ejaculatory volume
And unfortunately, these side effects can continue even after you’ve discontinued the drug (14).
Interestingly, these same side effects are less likely with natural ingredients.
The reason for this is still unknown, though the pathways by which the natural blockers work may differ from finasteride (15).
This is because finasteride is considered a steroidal inhibitor of 5AR (i.e. derived from the steroid hormone progesterone), while plant- and food-based alternatives are non-steroidal (15).
This difference may contribute to the differences in how the substances inhibit 5AR and, ultimately, block DHT.
Finasteride is not an option for women as it has not been approved for female use the FDA, so natural DHT blockers are the best option.
6 Topical DHT Blockers
Below are six DHT blockers which can be applied topically (i.e. to the skin).
Why Use DHT Blockers Topically?
Topical treatments make sense because they aim to treat the condition directly.
Topical DHT blockers can be applied to the scalp, and they work by blocking DHT at the follicles. Let’s take a look at some of the most effective options.
1. Saw Palmetto
Saw Palmetto, also known by its botanical name Serenoa Repens, is a plant that was commonly used by Native American communities (16).
There are three mechanisms by which saw palmetto is believed to be helpful in fighting hair loss (17). They include:
- Blocking 5AR, which is similar to the prescription drug finasteride
- Decreasing DHT uptake by hair follicles
- Decreasing the binding of DHT to androgen receptors
Of these, the most convincing is its 5AR-blocking abilities, which has been shown in two separate studies.
The first was done in 2012, and it compared the effectiveness of finasteride – a drug often used to block 5AR – and saw palmetto in treating AGA (18). This was an oral study, but it still sheds light on saw palmetto’s beneficial effects.
The study consisted of 100 men, all of which were diagnosed with mild to moderate AGA.
The men were split into two groups, of which one 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.
While finasteride did outperform saw palmetto, the plan still saw some of its own inspiring results. In fact, 38 patients had an increase in hair growth compared to finasteride’s 68.
But to really understand the topical effects of saw palmetto, let’s take a look at a more recent study.
In 2016, researchers applied saw palmetto to the shaved flank areas of syrian hamsters along with either DHT or testosterone (19).
The goal was to determine whether saw palmetto could be helpful in regrowing hair and, if so, how.
The results of this study showed that saw palmetto when combined with testosterone was more effective at reducing pigmentation – a sign of androgenic activities – than when combined with DHT.
Because saw palmetto works by inhibiting 5AR, as opposed to blocking DHT directly. However, the ultimate result is the same – with less 5AR there is less DHT and, therefore, less inflamed and irritated hair follicles.
The two most common formulations of saw palmetto – dried berry capsules and tablets – are oral. And saw palmetto taken orally has been shown to have some impact on hair growth (20).
But the capsules and tablets can also be crushed and added to carrier oils to be applied directly to the scalp.
2. Reishi Mushroom
Reishi has a few mechanisms which contribute to its positive hair growth effects, including antimicrobial and immunomodulatory (21, 22). However, the most prominent is its ability to inhibit 5AR and block DHT as a result (23).
In 2005, Japanese researchers studied the effects of 19 mushroom species on 5AR inhibition (23). The end goal was to determine which was best at inhibiting 5AR, and by how much.
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 below:
Reishi, also known as G.lucidum, showed the most inhibitory activity of all 19 species. In fact, it inhibited between 70 percent and 80 percent of 5ARs activities.
Researchers were also interested in reishi’s abilty to inhibit testosterone. The lower concentration (1.5 mg/kg) of G. lucidum was more effective than the higher concentration (15 mg/kg).
As the researchers put it “[t]he anti-androgenic activity of Ganoderma lucidum is an important biological activity for use with BHP patients.” However, this can also have implications for men and women with AGA.
This activity shows that reishi may be an effective inhibitor of 5AR, which is important for reducing DHT levels throughout the body including the scalp.
For AGA sufferers, then, reishi may be useful in reducing hair thinning and loss associated with the condition.
3. Stinging Nettle
Stinging nettle is a plant known for its stinging/burning effects. However, research shows it may also be useful as a topical DHT blocker.
The study in question was performed in 2011, and it consisted of rats with Benign Prostatic Hyperplasia (BPH) as induced by testosterone (24, 25). To determine the anti-androgenic effects of stinging nettle, the weight of the prostate was tracked throughout the study.
Why was prostate weight measured?
BPH is an enlargement of the prostate, which is believed to be caused by high DHT levels (26). To reduce prostate size, then, DHT levels must be reduced. As such, a reduction in prostate weight indicates anti-androgenic activities.
The results of the study showed that rats treated with stinging nettle saw a decrease in prostate weight.
This indicates that stinging nettle does, in fact, have anti-androgenic abilities and may be useful in reducing in other areas of the body such as the scalp.
4. Ecklonia Cava
Ecklonia cava is an edible alga found off the costs of Japan and Korea. This alga belongs to a larger group of algae, which consists of seaweeds and similar organisms.
Perhaps one reason for these benefits is its high polyphenol content (29). And of particular important to hair loss sufferers is its use as a hair growth promoter.
In 2012, a study performed on mice using the dieckol extract of E. cava was shown to induce anagen phase hair growth (30). To understand exactly what this means, it’s important to know how the hair growth cycle works.
There are three main phases of the cycle, which are:
Active hair growth only occurs during anagen, which also happens to be the longest of the three phases. However, conditions such as AGA can cause hair follicles to prematurely end anagen.
The mice in the study were treated with either:
- Vehicle (negative control)
- 0.5 percent E. cava enzymatic extract
- 5 percent minoxidil (positive control)
These treatments were carried out for 33 days, and photographs of the mice were taken at 1, 7, 13, 20, 26, and 33 days after shaving of the dorsal hairs.
As expected, minoxidil showed positive growth results and the mice in that particular treatment group saw significant hair growth. However, the E. cava group also saw significant increases in hair growth when compared to the negative control.
So, why is that?
Researchers took it a step further and compared the 5AR inhibitory activities of various concentrations of E. cava to finasteride. The initial results showed that higher concentrations of E. cava were effective at inhibiting 5AR.
And the dieckol extract showed to be the most effective of the four different extracts considered.
As described by researchers, these results were likely due to three main things.
Foremost, researchers stated that “anagen [phase] was induced on the back skin of C57BL/6 mice that were in the telogen phase of the cycle by depilation.” This was noted by the darkening in skin color that took place throughout the duration of the study.
The scientists also concluded that the dieckol extract of E. cava “could stimulate hair growth through the proliferation of dermal papilla cells and the inhibition of 5α-reductase activity.”
Does this mean that E. cava applied topically can promote hair growth?
The truth is that further studies – especially those on humans – need to be carried out before final declarations can be made. Though, the current results are promising and should offer hope to hair loss sufferers.
5. Rosemary Oil and Extract
Rosemary oil is one of the more versatile essential oils, as it has been shown to have various therapeutic health benefits. These include analgesic, antimicrobial, anti-inflammatory, and antioxidant properties (31, 32, 33).
But the most compelling benefit for hair loss sufferers is its 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 (34).
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 antiandrogenic activity. To do so, 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 percent and 94.6 percent, respectively. In comparison, finasteride only showed inhibitory activity of 81.9 percent in the same study.
According to researchers, “[t]hese results suggest that [RO-ext] inhibit[s] the binding of dihydrotestosterone to androgen receptors.”
Does this mean that rosemary oil and extract is the answer to your hair loss woes? Not necessarily.
As research on RO-ext’s use for hair growth has only been performed on mice so far, more studies (particularly those with human subjects) need to be carried out. This will give a better idea of rosemary’s true use as a hair growth promoter.
6. He Shou Wu (Fo-Ti)
He shou wu, also known as Fo-Ti, is an herb that’s used commonly within the Chinese tradition. And while it was used for centuries without any scientific evidence to back its claims, new research has shed light on its role in hair growth.
In 2015, researchers tested the effects of PMR and PMRP (two clinical preparations of Fo-Ti) on hair growth in mice (35). The study consisted of 88 mice in total, which were then split into 11 groups.
The two main delivery routes were oral and topical which made up seven and two groups, respectively, and there were also two groups which tested a combination of the two.
The groups to receive oral PMR saw a 96.5 percent average of hair covered skin ratio, while the oral PRMP preparation saw only 66.82 percent.
And what about topical results?
The group to receive PMR topical saw an average of 80.73 percent hair covered skin ratio, while the topical PRMP saw 89.51 percent.
This indicates that He Shou Wu, both orally and topically, may be an effective hair growth promoter.
The mechanism is still unclear, though researchers believe it has to do with its regulation of the Wnt signaling pathway. DHT and Wnt signaling are linked, which helps to explain its role in hair loss (36).
6 Internal DHT Blockers
Why Use DHT Blockers Internally?
Topical blocking of DHT can have many benefits, but these don’t remain in the long term. The answer, then, may be internal DHT blockers.
Internal DHT blockers can provide the same benefits as topical blockers with one major difference: they can be used to make a more pronounced shift in serum DHT levels and the presence of DHT at the follicular level (37).
1. Pumpkin Seed Oil
Another possible benefit of PSO, as explored by a 2014 research study, is hair growth (42).
The 24-week trial included 76 male subjects with mild to moderate AGA. Half were given a supplement containing PSO, while the other half were given a placebo. Both groups were instructed to take the “supplement” daily.
To analyze hair changes including hair counts and diameters, phototrichography was used (43). The analysis was performed at the start to establish patient baseline, at 12 weeks, and at 24 weeks.
The results show that the supplement-receiving group had significant increases in hair count over the placebo group:
So, while PSO was not the only ingredient contained within the supplement, researchers do believe it played a major role in the results. However, further studies will be helpful in gaining a better understanding of the role of PSO and its mechanisms.
NOTE: The supplement provided to participants was Octa-Sabal Plus, which does contain pumpkin seed powder but also additional ingredients. These include Octacosanol (from vegetable powder), Gamma linolenic acid (from evening primrose), and Lycopene (from tomato powder). This means there’s no way to definitively say whether the PSO was the source of the study’s results, or if the other ingredients also played a role (which is likely).
2. Green Tea
Green tea has gained quite a reputation in recent years, and for good reason. Its mix of polyphenols – particularly, flavonoids and flavonols, and other components means it packs a serious punch when it comes to health (47, 48).
And more recently, the effects of green tea and its components on hair growth has been noted and researched.
For example, a 2005 study performed on mice showed that drinking green tea more specifically, it’s polyphenic compounds may promote hair growth (49).
The female mice recruited for the study were sufferers of spontaneous hair loss on the head, neck, and dorsal (back) areas. There were 60 in total, and they were split into two groups:
- Group A received 50 percent fraction of polyphenol extract from dehydrated green tea in their drinking water for six months
- Group B received regular drinking water
All other factors including diet and living environments were the same between groups.
At the end of six-month study, 33 percent of the mice in Group A had significant hair growth. There was no notable hair growth seen in Group B.
What was the main reason for these results?
Researchers concluded that “anti-inflammatory and stress inhibitory effects of [green tea’s polyphenolic substances] may influence hair regrowth among mice.”
Perhaps you’re wondering, does green tea also block DHT? And a more recent study, performed in 2013, would say indicate yes (50).
Epigallocatechin-3-gallate (EGCG) is a polyphenolic compound and it’s actually one that’s 40 percent of green tea’s polyphenolic makeup (47). EGCG itself has been shown to inhibit 5AR activities (51).
For hair loss sufferers, this means that EGCG – and green tea as a result – may be beneficial in reducing 5AR activities so as to block the production of DHT.
This may then contribute to improved hair growth over time.
3. Stinging Nettle
Stinging nettle is a plant that’s often ‘feared’ for its stinging effects. Its extracts have been shown to be quite effective in blocking DHT topically and may have the same effects when taken orally.
Benign Prostatic Hyperplasia (BPH) is a medical condition in which the prostate gland is enlarged (25). It’s very common in aging men, and it can cause symptoms such as increased need to urinate and weak urine stream.
But what does this have to do with hair loss?
BPH is a condition that is characterized by increased 5-alpha-reductase activities (52). Any treatment that reduces the size of the prostate, then, likely plays a role in reducing these activities.
One such treatment? Stinging nettle.
In 2009, 620 BPH patients were recruited for a study with one goal: to understand the effects of Urtica dioica (saw palmetto) on prostate size. The study was conducted over six months, and the various models and measurement techniques included:
- International Prostate Symptom Score (IPSS)
- Maximum urinary flow rate (Qmax)
- Postvoid Residual Urine Volume (PVR)
- Serum Pros-tatic-Specific Antigen (PSA)
- Testosterone levels
- Prostate size
The participants were split into two groups – those that received stinging nettle, and those that received a placebo.
Both the IPSS and Qmax decreased significantly in the stinging nettle group.
But what exactly does this mean for hair loss sufferers?
As treatment of BPH is an indicator of 5AR inhibition, this study shows that stinging nettle can be used to inhibit 5AR effectively. This is beneficial for anyone suffering from androgen hair loss.
And that wasn’t even the only study to show stinging nettle’s inhibitory effects. Another study performed in 2015 on rats, showed similar effects on prostate size (53).
The ingredients on this list are packed full of nutrients, and flaxseeds are no exception.
Flaxseed and its oil derivative are composed mostly of omega fatty acids and lignans (54). Both of these substances have been shown to positively affect hair growth in one way or another, so it makes sense that flaxseeds have the same effect (55, 56).
The results of one study seem to prove this.
This 2013 study measured the effects of plant-based lignans on DHT – including flaxseed, sesame, safflower, and soy (55). The lignans were administered orally either in powder form or as a petroleum extract.
The study used castrated male rats and researchers were particularly interested in prostate weight as lowered weight would indicate less androgenic activity.
So, how did flax lignans perform?
Both the powdered and petroleum extracts of flax decreased prostate weight, as well as lowered testosterone levels. These indicate the inhibition of 5AR.
And while this is strong evidence, it’s not the only study to highlight flaxseeds‘ possible role in hair growth.
Scientists from Algeria wanted to know whether flaxseed could have a direct impact on hair growth. To find out, they gathered 16 rabbits which were split into two groups (57):
- Group A: The control group, which received regular rabbit feed
- Group B: The test group, which received rabbit feed infused with crushed flax
The study took place over three months, and to measure results, researchers would shave an area of each rabbit’s back and track growth. Hair length, width, and the mean weight of shaved hair were all taken into consideration.
In the end, the flaxseed supplement group experienced an improvement in hair length, width, and mean weight.
And while researchers were hesitant to discuss the mechanism behind flax’s hair-growth promoting abilities, it’s likely that the inhibition of 5AR as shown previously is one reason.
5. Sesame Seeds
The 5AR-inhibiting effects of flax cannot be mentioned without also discussing sesame seeds since both seeds were used in the same study that showed the positive effects of plant-based lignans on 5AR inhibition (55).
In this particular study which tested the effect of lignans on prostate weight in castrated male rats, sesame was shown to reduce prostate weight while also lowering testosterone levels.
And while there’s no definitive answer as to why sesame seeds are powerful inhibitors of 5AR, it may have to do with their nutritional composition, since they do contain polyphenols, sterols, and essential fatty acids similar to flax (29, 58, 59).
BPH has come up a few times in this post, and for good reason. Similar to AGA, BPH is believed to be ‘triggered’ by a sustained increase in DHT levels. And just as some other DHT blockers have been proven helpful in treating BPH (and AGA, as a result), pygeum is the same.
Pygeum is a bark from the Pygeum africanum tree and studies have indicated it may be a useful treatment for BPH (60).
One study even showed that supplementation with Pygeum reduced symptoms of the condition, and these patients were twice as likely to report improvement than the placebo-receiving group (60).
Exactly which symptoms were reduced?
Three in particular were studied. In pygeum-receiving patients nocturnal urination was reduced by 19 percent, residual urine volume was reduced by 24 percent, and peak urine flow was increased by 23 percent.
The Potential Dangers of Blocking DHT Internally
While the benefits of internal DHT blockers were discussed previously, there is one thing to keep in mind – blocking DHT entirely can have negative health benefits.
DHT, while commonly demonized by the hair loss community, does play numerous roles in the body. Foremost, it’s essential in early sexual development (5). It’s also been known to contribute to and help regulate male sexual behaviors (61).
Due to this, blocking DHT entirely is not the goal. But unfortunately, that can happen much more easily with an internal DHT blocker than topical.
To be sure you’re blocking just enough DHT to improve hair growth but not impact sexual vitality, pay attention to how you feel.
If you choose to supplement with oral DHT blockers, you’ll want to do so slowly and with caution. This means you need to track dosages as well as any accompanying symptoms.
If symptoms that are indicative of sexual dysfunction do appear, then reduce your dosage.
And also keep in mind the plant- and food-based DHT blockers mentioned above are much less likely to induce side effects. As mentioned, this is due to the fact that they’re non-steroidal blockers as opposed to steroidal (such as finasteride).
So, what types of symptoms should you be looking for exactly? Well, let’s consider the side effects that are most common among finasteride users (12). The less severe side effects include:
- Dizziness and lightheadedness
- Swelling of the hands and feet
However, more severe side effects such as anxiety and depression can also occur as a result of blocking DHT (13).
And for many men, the worst of the possible side effects are those related to sexual function. These occur in 2.1 percent to 3.8 percent of finasteride users, and they may also occur with the use of natural blockers (12).
Perhaps the most common is Erectile Dysfunction (ED), or the inability to get or maintain an erection. A loss of ejaculatory volume is another common side effect, as well as loss of libido (62).
And unfortunately, as mentioned previously, these can continue even after finasteride has been discontinued (14).
The Alkaline Diet: The Best Way to Block DHT?
The trouble with blocking DHT – either topically or internally – is that it’s a temporary fix for a permanent problem. While using DHT blockers may minimize the impact of pattern hair loss, it doesn’t treat it.
That’s why another factor must be taken into consideration, and that’s acid/alkaline balance. Let me explain.
The human body is a fine-tuned machine. As such, it requires a very specific pH level to function as it should. This happens to be about 7.4 or, more specifically, a slightly alkaline range of between 7.35 and 7.45 (63).
But there are a few factors which play a role in pH balance, and one of the really big ones is diet.
That’s right – the foods we eat fall somewhere on the pH scale, from acidic to alkaline, and these can contribute to our own pH levels.
The foods we eat, once metabolized, leave behind an ‘ash’. This ash is either net acidic or alkaline, depending on the pH value of the food.
The more acidic foods we eat, the more acidic our blood serum levels can become. The same goes for alkaline foods, which can bring our serum levels onto the more alkaline side.
The obvious answer then is to increase alkaline foods in your diet.
But what about DHT and hair loss – where does that fit in?
Well, just as with any enzyme, 5AR – the enzyme responsible for testosterone conversion to DHT – functions optimally in its own very specific pH range. More specifically, it functions best within the range of 5 – 5.5 (66).
This means that 5AR functions best in a more acidic environment and plays a bigger role in pattern hair loss.
By alkalizing our bodies (and ensuring they remain in their most alkaline state), we can reduce the activities of 5AR and more appropriately treat the hair loss.
And while an alkaline diet can seem daunting, there are many things that can make it even easier to achieve. For example, juicing vegetables to increase your intake more efficiently and reducing intake of processed foods are just two ways to start.
Does this mean you can’t also use topical and internal DHT blockers? Of course not.
However, you’ll certainly need to rely on them less over time as your body becomes less hospitable for 5AR.
In the end, you may be wondering whether DHT blockers are your best hope of regrowing your hair. The answer to this will depend on many factors.
Overall, DHT blockers (both topical and internal) can be helpful in reducing the interactions between the androgen DHT and your hair follicles. This can reduce instances of follicle miniaturization which is a tell-tale sign of AGA and put a stop to hair loss.
It may even help to regrow your hair.
But this isn’t the only or even the best way to treat AGA.
To treat the condition, you must focus on permanent lifestyle changes. These include alkalization of your diet, as well as reductions in stress and in health-harming activities such as smoking and drinking.
Only with these changes will you begin to see real and long-lasting results.