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 about 12 natural DHT blockers that may be helpful in fighting hair loss. 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 may work in the same vein.
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 popular 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 (12).
There are three mechanisms by which saw palmetto is believed to be helpful in fighting hair loss (13). 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.
Study: Comparitive effectiveness of finasteride vs Serenoa repens in male androgenetic alopecia: a two-year study.
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 (14). 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.
Study: Effect of saw palmetto supplements on androgen-sensitive LNCaP human prostate cancer cell number and Syrian hamster flank organ growth
In 2016, researchers applied saw palmetto to the shaved flank areas of syrian hamsters along with either DHT or testosterone (15).
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 (16).
But the capsules and tablets can also be crushed and added to carrier oils to be applied directly to the scalp.
Limitations and Considerations
As mentioned, it’s possible to take saw palmetto orally. And the only study to test saw palmetto and its efficacy in hair regrowth done in humans was performed using an oral dose.
However, there are many reasons to avoid oral intake of saw palmetto.
Foremost, the supplement tends to have side effects similar to those of finasteride. So, if you’re worried about avoiding finasteride side effects (which aren’t as common as previously believed) then saw palmetto taken orally isn’t a great option. This is especially true since finasteride was shown to be more effective.
And what about topical?
As the study was carried out on hamsters, there’s no way to tell how effective it can be in humans. You must also consider that the hamsters were not suffering from alopecia, but were instead shaved.
So, while saw palmetto may show anti-androgen properties on the flank organ of syrian hamsters, it cannot be said that the same with occur in the human scalp at this point.
2. Reishi Mushroom
Reishi has a few mechanisms which contribute to its positive hair growth effects, including antimicrobial and immunomodulatory (17, 18). However, the most prominent is its ability to inhibit 5AR and block DHT as a result (19).
Study: Anti-androgenic activities of Ganoderma lucidum
In 2005, Japanese researchers studied the effects of 19 mushroom species on 5AR inhibition (19). 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.
Limitations and Considerations
It’s obvious that reishi is able to suppress androgens in a laboratory environment, but can the same be said in humans?
Unfortunately, this is something that cannot be known for sure without further research.
And it’s also important to know that long-term effects of topical use have not been tested in humans, though it was shown to be non-toxic in rats over a period of three months (20).
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.
Study: Ameliorative effects of stinging nettle (Urtica dioica) on testosterone‐induced prostatic hyperplasia in rats
The study in question was performed in 2011, and it consisted of rats with Benign Prostatic Hyperplasia (BPH) as induced by testosterone (21, 22). 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 (23). 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.
Limitations and Considerations
As will be pointed out in various areas throughout this article, the anti-androgenic effects of stinging nettle have been shown in animal models (in this case, rats) but have yet to be proven in humans.
Does this mean you should avoid the plant?
Not necessarily, but you should be aware of its side effects.
When applied topically, stinging nettle has been shown to cause hives, rash, and general irritation (24). This could be dangerous if applied without first testing on a small patch of skin, such as the inside of your wrist.
You should also be prepared to not see much in the way of results, as it’s still not known whether the anti-androgen effects will occur similarly in humans as they do in rats.
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 (27). And of particular important to hair loss sufferers is its use as a hair growth promoter.
Study: Effect of dieckol, a component of Ecklonia cava, on the promotion of hair growth
In 2012, a study performed on mice using the dieckol extract of E. cava was shown to induce anagen phase hair growth (28). 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 (29, 30, 31).
But the most compelling benefit for hair loss sufferers is its proven ability to inhibit 5AR.
Study: Promotion of hair growth by Rosmarinus officinalis leaf extract
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 (32).
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.
Limitations and Considerations
Rosemary oil and other essential oils – including peppermint and cedarwood – have been growing in popularity in recent years. However, there are a few things to consider before you begin to use them yourself.
First and foremost, essential oils are highly concentrated plant extracts and, as such, they can cause significant irritation and even chemical burns to the skin. This is why they absolutely must be diluted with a carrier oil, but you should also always test the combination on your skin before applying to your scalp.
You should also consider that, when looking at the results of the study above, that mice were the subjects and the results therefore may not translate to humans.
There have been studies performed on human subjects, particularly this one published in 1998 and performed on patients with alopecia areata (33). But the use of rosemary was combined with other oils, and it was tested via aromatherapy as opposed to topical application. These results have also yet to be duplicated.
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.
Study: Hair growth promotion activity and its mechanism of Polygonum multiflorum
In 2015, researchers tested the effects of PMR and PMRP (two clinical preparations of Fo-Ti) on hair growth in mice (34). 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 (35).
6 Internal DHT Blockers
Now it’s time to look at oral, also known as 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 (36).
1. Pumpkin Seed Oil
Another possible benefit of PSO, as explored by a 2014 research study, is hair growth (41).
Study: Effect of pumpkin seed oil on hair growth in men with androgenetic alopecia: A randomized, double-blind, placebo-controlled trial
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 (42). 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.
Limitations and Considerations
Before you consider this study to be proof of PSO’s ability to regrow hair, there’s one major thing to keep in mind:
The supplement provided to participants was Octa-Sabal Plus, which does contain pumpkin seed powder (not oil) 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).
There’s also another thing to consider, and that’s the results seen in both the treatment and placebo groups.
While researchers claimed that the treatment group saw a 40 percent increase in hair count compared to the 10 percent increase in hair count in the placebo group, the hair thickness comparisons were very similar.
As reported by the study, the group to receive the supplement saw a 360 percent increase in hair thickness. That seems impressive at first, but not as impressive when you consider that the placebo group saw a 350 percent increase!
Why is it that the placebo group also saw an increase?
It may be that the placebo effect was very strong in both groups (as neither group knew whether they were receiving the treatment or the placebo) (46).
It could also be that there was another reason for the increase in hair thickness in both men, such as seasonal changes.
That’s not to say that the study doesn’t provide a few things to consider. However, a study using PSO only would be much more effective at determining efficacy.
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.
Study: The effects of tea polyphenolic compounds on hair loss among rodents
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 indicate yes (50).
Study: Identification of a new plant extract for androgenic alopecia treatment using a non-radioactive human hair dermal papilla cell-based assay
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 (22). 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.
Study: Urtica dioica for treatment of benign prostatic hyperplasia: a prospective, randomized, double-blind, placebo-controlled, crossover study
In 2005, 620 BPH patients were recruited for a study with one goal: to understand the effects of Urtica dioica (stinging nettle) on prostate size (53). 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 (54).
Limitations and Considerations
While the main study mentioned above does indicate the efficacy of stinging nettle in the treatment of BPH, the study which highlights its effects on hair growth was performed on rats.
And interestingly, a previous study showed that stinging nettle may not be linked to a reduction in DHT levels at all (55).
This means that further studies – perhaps an updated study which again compares finasteride and stinging nettle – would be beneficial in understand the exact role, if any, that nettle may play.
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 (56). 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 (57, 58).
The results of one study seem to prove this.
Study: Biological evaluation of anti-androgenic effect of some plant foods
This 2013 study measured the effects of plant-based lignans on DHT – including flaxseed, sesame, safflower, and soy (57). 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.
Study: Pharmacological aspect of Linum usitatissimum: Flax ingestion on hair growth in rabbits
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 (59):
- 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.
Limitations and Considerations
Lignans are the main components of flaxseeds believed to play a role in hair growth. But they actually may play a role in increased serum DHT.
In a 1997 study, lignans were shown to bind to sex hormone-binding globulin (SHBG) (60). SHBG usually binds to testosterone and DHT, which then prevents them from binding to androgen receptors. But with lignans taking the place of testosterone and DHT, this means that more of these sex hormones are available within the body.
It’s obvious that there is some conflicting beliefs on this, so further research would be helpful.
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 (57).
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 (27, 61, 62).
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 (63).
Study: Pygeum africanum for benign prostatic hyperplasia
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 (63).
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 (64).
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 (65).
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 (66).
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 (67).
Why Natural DHT Blockers May Not Be the Answer (And What to Do Instead)
So, if natural DHT blockers contain the same side effects as finasteride but with very little scientific proof of their results, what should you do to promote hair regrowth instead?
Well, you could consider the more traditional treatment options.
If the risk of side effects with natural DHT blockers is similar to that of finasteride, then avoiding finasteride doesn’t seem all that practical.
And perhaps most importantly, finasteride has been scientifically proven to be effective in humans with AGA time and again.
Study: Finasteride in the treatment of men with androgenetic alopecia
One review study, published in 1998, tracked the results of two one-year studies which consisted of a total of 1,553 men (18 to 41 years old) with male-pattern hair loss (68).
The first one-year study consisted of groups of men receiving either finasteride or a placebo, and the second one-year study followed the progress of 1215 of the men in the original study into a second year.
The efficacy of the results was evaluated by scalp hair counts, patient and investigator assessments, and review of photographs by an expert panel.
The baseline hair count in both groups was an average of 876 hairs in a one-inch circular area of the scalps. These numbers increased by 107 and 138 hairs at the one- and two-year marks, respectively. However, the placebo group saw an increase in hair loss throughout the study.
And while side effects are always stated as being a reason to avoid finasteride, there is no definitive answer as to how common they are.
One recent study of 3,177 men showed that only 23 (0.7 percent) participants experienced adverse effects, but only seven men deemed them severe enough to discontinue treatment (71).
Dutasteride works similarly to finasteride, but with one notable difference: Instead of blocking just one type of 5-alpha-reductase, it blocks two.
In simplest terms, it blocks the production of DHT more effectively than finasteride. How much more effectively?
Similar to finasteride, the effects of the drug are also dose dependent.
Just 2.5mg of dutasteride was shown to be superior to 5mg of finasteride in a 24-week study which consisted of 416 men (74).
If the side effects associated with blocking DHT have become too much for you, you may want to consider minoxidil.
The drug’s mechanism isn’t exactly known, but it’s believed to open potassium channels which helps to increase blood flow and oxygen- and nutrient-delivery to the scalp (77). It’s also been shown to upregulate certain growth factors in the hair follicles (78).
Instead of blocking DHT, it makes it possible for your hair follicles to thrive in an otherwise hostile environment.
As the first FDA-approved treatment for AGA, there are also plenty of studies to back its efficacy.
Study: Changes in hair weight and hair count in men with androgenetic alopecia, after application of 5% and 2% topical minoxidil, placebo, or no treatment
One study, performed over 120 weeks, showed significant changes in hair weight in the treatment groups when compared to baseline (79). In fact, over 96 weeks “topical minoxidil induced and maintained an increase in interval weight over baseline of about 30%”.
These long-term positive results were seen before, too.
The first long-term study, published in 1987, showed that minoxidil helped patients to maintain the initial regrowth over a period of two years (80).
Increasing blood flow
Freund et al showed that the enzymatic conversion of testosterone to DHT is oxygen dependent. So, theoretically by increasing blood flow throughout the capillaries of the scalp, and the increased oxygen that comes with it could help to ‘block’ DHT.
Mechanical offloading devices such as the growband may be able to help increase blood flow by reducing scalp tension. This could be a promising way to help block DHT without the side effects that come with a systematic hormone blocker such as finasteride.
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, natural DHT blockers (both topical and internal) may be helpful in reducing the interactions between the androgen DHT and your hair follicles. This may 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 not all natural options are better than the traditional medications, including finasteride and dutasteride.
That’s not to say that using natural methods in addition to traditional options wouldn’t be helpful, but do be aware of the possible side effects and limitations of many of the natural choices.