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Learn MoreMany men worried about finasteride’s sexual side effects instead opt to use a natural DHT blocker – like pumpkin seed oil or saw palmetto – to help fight hair loss. Their rationale: these extracts lower DHT levels, but they are naturally derived and therefore won’t cause problems like low libido. What these men don’t realize? Natural DHT blockers often cause fewer sexual side effects because they’re less effective at reducing DHT and fighting hair loss. This article dives into the research, concerns, and limitations of using finasteride and natural DHT reducers for hair growth – and their risks of sexual problems.
When it comes to treating hair loss, many men feel trapped between two terrible choices:
Choice #1: Start taking a drug forever that will help fight hair loss – but at the risk of developing sexual side effects (that are sometimes reported as permanent).
Choice #2: Don’t take that drug… and instead, accept that you will continue to lose your hair.
This is exactly how I felt when, at 17-years old, my doctor diagnosed me with pattern hair loss and then prescribed to me Propecia.
Propecia – an FDA-approved drug – helps slow, stop, and even partially reverse hair loss by reducing the amount of DHT in our bodies (a hormone that may trigger pattern hair loss).
Unfortunately, the hormone DHT (dihydrotestosterone) isn’t just implicated in hair loss… It’s also critical for male sexual development. In fact, men who have never been able to produce normal amounts DHT tend to suffer from low libido and poor genital development. So it’s no surprise that the drug Propecia (Finasteride) – a DHT reducer – is often maligned online as causing similar side effects: lower sex drive, poorer quality erections, and in rare cases, impotence. For an unlucky few, these sexual side effects might persist even after they stop taking the drug (although the evidence here is still debated).
As a high schooler with thinning hair, I didn’t want to risk impotence – no matter how small the chance. So I decided against taking Propecia.
But here’s something I never understood…
Many People Are Afraid To Take Finasteride To Reduce DHT, So They Instead Take “Natural” Supplements To Reduce DHT. What Difference Does It Make?
Many hair loss sufferers who fear Propecia’s sexual side effects instead take what they call “natural” DHT reducers… supplements like saw palmetto or pumpkin seed oil.
Their rationale? They say that “natural” DHT blockers reduce DHT… but without the same sexual side effects as Propecia.
At first glance, that makes no sense. Propecia, saw palmetto, and pumpkin seed oil do the same thing: they decrease DHT. But DHT is required for proper sexual development. So how come Propecia has a history of sexual side effects… while, according to some supplement advocates, “natural” DHT blockers don’t?
Or maybe these supplement takers are wrong about their “natural” DHT reducers. Maybe these supplements do cause sexual side effects, but no one has ever looked deep enough in the literature.
This article uncovers the answers. By the end, you will learn:
Warning: this article gets technical. But if you’re considering taking any kind of natural DHT blocker – then you might want to read this content.
Let’s start by reviewing how DHT is connected to pattern hair loss, how reducing DHT might help fight thinning hair, and where Finasteride comes into play.
When I was first diagnosed with pattern hair loss, I asked my doctor why my hair was falling out. His answer:
DHT (a hormone made from testosterone) is higher in the scalps of balding men. For reasons not entirely understood, our hair follicles start to become more sensitive to DHT, and then begin to shrink over a series of hair cycles. The end result: pattern hair loss (and eventually baldness).
Beyond this relationship, the DHT-hair loss connection is cemented by two major findings:
While researchers still can’t explain why DHT causes hair loss, the evidence is clear: (1) men who can’t produce DHT don’t go bald; and (2) balding men have elevated DHT levels in their balding regions. So goes the DHT-hair loss connection…
These findings were the basis for pharmaceutical companies to develop drugs that could reduce DHT, and hopefully reverse pattern hair loss.
Enter Propecia… A Drug That Reduces DHT
Finasteride (branded as Propecia) reduces DHT. How? By inhibiting an enzyme known as type II 5-alpha reductase.
Remember how DHT is made from testosterone? Well, this conversion doesn’t just happen on its own. In order for testosterone to convert into DHT, it needs the help of an enzyme called 5-alpha reductase.
5-alpha reductase is an enzyme required for our bodies to convert free (unbound) testosterone into DHT. Without 5-alpha reductase, this conversion doesn’t happen.
The 5-alpha reductase enzyme comes in a few types, but the one that is of highest interest to hair loss researchers is type II 5-alpha reductase. Why? Because type II 5-alpha reductase is the exact enzyme needed to convert testosterone into DHT in our prostate tissues and scalp skin.
Do you recall that rare genetic mutation which prevents some men from going bald? That mutation is actually a type II 5-alpha reductase deficiency. The reason why men with that mutation don’t go bald is because they don’t have any scalp DHT, and the reason why they don’t have any scalp DHT is because their bodies can’t produce the type II 5 alpha reductase enzyme.
Finasteride’s goal: to do the same thing.
The logic behind Finasteride is as follows: if we can stop type II 5-alpha reductase from forming, then we can stop DHT from binding to our scalps.
Finasteride (Propecia) does exactly this. It inhibits type II 5-alpha reductase, and in doing so, reduces DHT levels in our prostates, scalps, and other tissues.
Yes. While studies show that Finasteride (Propecia) isn’t great at regrowing all lost hair, the drug can significantly slow, stop, or even partially reverse the progression of pattern hair loss.
But for a select few, this may come at the cost of sexual side effects.
Depending on the dose, Finasteride can reduce serum levels of DHT by ~70%.
While this may help regrow hair, a DHT reduction this severe sometimes coincides with the following side effects:
Propecia’s manufacturers say these effects are rare and only impact up to 2% of drug users. But some studies suggests that incidence is much higher.
In one study, men taking 5mg daily of Finasteride saw a 15% incidence in sexual side effects within one year. And while this isn’t a perfect apples-to-oranges comparison (when it comes to hair loss, most Finasteride users take up to 1mg daily instead of 5mg), it’s an indicting example of how 5-alpha reductase inhibiting drugs may curb our sexual performance.
There are many foods (and food derivatives) that also reduce 5-alpha reductase activity, and thereby DHT levels.
For example, studies show that the extract from saw palmetto fruit is a 5-alpha reductase inhibitor. And some studies suggest the fatty acids in pumpkin seed oil also reduce DHT levels.
There’s also evidence that a seaweed extract called ecklonia cava may have DHT-reducing capabilities. And even the volatile oils inside rosemary and peppermint extracts show some ability to reduce 5-alpha reductase activity.
Many hair loss sufferers refer to these extracts and concentrations as “natural” DHT reducers. And as a result, most people also consider these safer.
But are these food derivatives actually safer than Finasteride? The research is more complicated than you’d expect…
And even more complicated? People’s definitions of the term, “natural”… And why, for some reason, these DHT blockers are considered “natural” while Finasteride isn’t.
When we define things as natural or unnatural, what do we mean?
Some people say that “natural” is anything that can’t kill you. According to these people, substances like cyanide or arsenic are unnatural.
Unfortunately, both cyanide and arsenic are naturally-occurring substances found all over the world. And they can kill us fairly easily.
Other people loosen their definition of “natural” to anything that isn’t harmful to our health – like water. But if we think about this critically, too much of anything can harm us. In fact, too much water can kill us.
Then we’ve got a group of “natural” thinkers who are sort of scientifically literate. They say that anything made in nature = natural. Anything made in a lab = unnatural.
I decided to poll ten people who agreed with this definition. When I asked if they considered steroids unnatural, 100% said yes.
Then I explained that synthetic estrogens (a lab-made steroid) are made from concentrations of the “natural” food source wild yams. And so came another tightening of their natural definition…
My point is this: people have wildly different takes on what is natural, and what isn’t. So before you go throwing out the term, make sure you know where your definition of “natural” starts and stops.
For purposes of this article, we’re going to draw a hard line too.
I think a fair definition of a “natural DHT inhibitor” is one that is…
For example: pumpkin seed oil and saw palmetto extract fit my definition of natural DHT inhibitors. Why?
For one, both are derived from foods. Pumpkin seed oil is made by cold pressing the seeds of pumpkins. Saw palmetto extract is made by extracting the polyphenols, phytosterols, and fatty acids from the saw palmetto fruit.
And aside from being highly concentrated, these extracts aren’t chemically altered. In other words, they’re not molecularly modified to look and act like a hormone in our bodies.
Now contrast this with Finasteride (Propecia).
Finasteride is synthetic. It’s made in a laboratory by modifying the chemical bonds of progesterone – an endogenous sex steroid released by the ovaries and the placenta during pregnancy.
And based on our research, Finasteride is not made from food. It’s a chemically altered derivative of progesterone that binds to a cofactor required for type II 5-alpha reductase expression, and as a result, stops that expression from happening.
As a result, I consider saw palmetto and pumpkin seed oil natural, and Finasteride as unnatural (at least if I had to put definitions on them).
Now that we know just how pure and “natural” saw palmetto and pumpkin seed oil are, surely they must be devoid of sexual side effects… I mean, they shouldn’t boast any sexual problems like the “unnatural” drug Finasteride… Right?
Wrong. (Sort of).
While the evidence is mixed, there are some reports that saw palmetto is sometimes associated with sexual dysfunction such as decreased libido.
The good news? These side effects seem less common with saw palmetto versus Finasteride. Moreover, the adverse effects of saw palmetto (if any) appear to be mild and infrequent. Lastly, a recent large multi-center study found no evidence of significant adverse effects (including sexual dysfunction) after 18 months of treatment with saw palmetto… at three times the typical dose.
We can’t say the same about mega-dosing with Finasteride, as that earlier study showed that 5mg daily dose resulted in a 15% incidence of male sexual side effects in just one year. At the same time, I’m making a crude apples-to-oranges comparison. If we really wanted to answer this question, we’d need to compare Finasteride against saw palmetto within the same clinical trial… and ask the participants detailed questions about rates of sexual side effects.
That research currently doesn’t exist. So we’re left drawing crude comparisons and taking our best guesses.
The bottom line: there’s some evidence that saw palmetto may cause some sexual side effects. But these effects are probably much milder versus Finasteride.
So, what about other “natural” DHT reducers – like pumpkin seed oil?
There are reports that pumpkin seed oil may cause ejaculation problems. However, several recent studies on patients receiving pumpkin seed oil over 6-12 months have shown no significant sexual side effects.
We also haven’t observed any sexual side effects with topical rosemary oil use – another anti-androgenic extract. And ironically, the seaweed extract ecklonia cava may reduce DHT levels in men while simultaneously improving their sexual function.
And this brings us back to our main question…
How can both natural 5-alpha reductase inhibitors and Finasteride reduce DHT… but only Finasteride is associated with higher rates of sexual dysfunction?
There are at least four possibilities.
This is called the nocebo effect, and it happens all the time in research.
For example, one study on Finasteride showed that simply by warning patients of the potential for side effects, reports of side effects rose by over 500%. The implication? Maybe many of the side effects reported by Finasteride users are psychosomatic.
When we follow this logic further, things get even more interesting. For instance, the effects of certain drugs – both positive and negative – seems to vary by cultural group. For instance, while saw palmetto is sometimes associated with sexual side effects in the U.S., it was also celebrated as an aphrodisiac for some indigenous groups.
Same plant, same ingredients, but two opposing effects.
Moreover, some studies on minoxidil have shown that men have regrown significant amounts of hair… in the placebo group! Similarly, studies on finasteride have shown men have lowered their DHT levels… by taking sugar pills!
The mind is a powerful thing.
So, maybe these “natural” DHT reducers don’t cause nearly as many side effects… simply because we don’t think they should.
There are an overwhelming number of studies on Finasteride and its sexual side effects. On the contrary, there are fewer studies on saw palmetto, pumpkin seed oil, and other natural DHT reducers. By volume alone, the literature skews heavily against Finasteride. As a result, we might be making misleading conclusions about these “natural” DHT reducers.
But for a moment, let’s assume this isn’t true.
Instead, let’s take the current body of evidence at face value: despite the fact that Propecia and food-based extracts reduce DHT, Propecia causes significantly more sexual side effects than saw palmetto or pumpkin seed oil.
The question is… why?
Well, there are two remaining possibilities.
First, that natural DHT reducers aren’t as effective at reducing DHT as a drug like Propecia, and as a result, produce fewer sexual problems.
And secondly, that natural DHT blockers reduce DHT through a completely different set of mechanisms, and that only certain DHT-reducing mechanisms are to blame for Finasteride’s negative side effects
Let’s take these one-by-one.
This is an uncomfortable truth for most “natural” DHT reducer advocates: these natural compounds are probably less effective at reducing DHT versus Finasteride.
Studies have shown that Finasteride decreases serum DHT levels by 71% after 24 weeks of use. Similarly, Dutasteride has been shown to lower serum DHT by 95 % after 24 weeks.
Finasteride and Dutasteride also reduce scalp DHT by 64% and 51%, respectively. Finasteride reduces prostatic DHT levels by 85%, and Dutasteride reduces prostatic DHT levels by 97% over 6-10 weeks.
Those are some serious reductions. So how do food-based 5-alpha reductase inhibitors compare?
Sadly, we don’t really know. But based on the evidence so far, these food-based DHT reducers are much less effective.
In a randomized trial, saw palmetto reduced prostate tissue DHT levels by 32%.
Another study showed that saw palmetto inhibits the activity of type II 5-alpha reductase by 76%, and Finasteride by 82%. Unfortunately, there was no evaluation in actual DHT levels. And to make matters worse, when we compare half-lives and metabolism rates of saw palmetto versus Finasteride, the 5-alpha reductase reduction from saw palmetto appears much shorter-lived.
Even worse news: there are no studies evaluating “natural” DHT blockers and their reduction in DHT levels in the prostate or scalp. And when it comes to pattern hair loss, the scalp is where DHT reduction really counts.
Based on the limited evidence – if we control for dosage sizes, half-lives, and the studies above – our best guess is that natural DHT blockers reduce DHT levels by just 1/3rd of what a synthetic DHT blocker can achieve.
This would also explain why saw palmetto isn’t as effective as finasteride: it’s just not as powerful.
The take home note? With less of a reduction in DHT, fewer sexual side effects will arise. So it’s no wonder that food-based DHT reducers are associated with fewer sexual problems.
But this might not be the “big” reason why natural DHT reducers boast fewer sexual side effects. In fact, it might be due to the actual structure of these synthetically-made drugs.
Remember how we defined “natural” versus “unnatural”? Natural is food-based and chemically unaltered; unnatural is not from food and chemically synthesized.
Well, chemists also divide 5-alpha reductase inhibitors into two categories:
Examples of steroidal 5-AR inhibitors: Finasteride and Dutasteride. Why? Because these drugs are chemically synthesized from the sex steroid progesterone.
Examples of non-steroidal 5-AR inhibitors: saw palmetto extract and pumpkin seed oil. Why? Because these compounds are simply food concentrations.
Interestingly, steroidal 5-alpha reductase inhibitors may reduce DHT differently than non-steroidal 5-alpha reductase inhibitors.
Remember our chart from earlier? Free testosterone is converted into DHT by the enzyme 5-alpha reductase…
But in reality, this process isn’t that straightforward.
Why? Because 5-alpha reductase doesn’t just pop up out of nowhere. It actually needs the help of a cofactor to form and mediate the DHT conversion process. And what is that cofactor? A coenzyme known as nicotinamide adenine dinucleotide phosphate… or to put it simply, NADPH.
Finasteride works on a molecular level by binding to and altering the structure of NADPH. It changes NADPH it into a different cofactor – one that doesn’t allow 5-alpha reductase to form.
The end-result: a direct decrease in 5-alpha reductase expression.
This is an example of direct 5-alpha reductase inhibition. And based on the evidence, this is exclusively how steroidal 5-AR inhibitors reduce DHT.
But non-steroidal 5-AR inhibitors behave differently in the body. And these differences might explain the lacking sexual side effects.
Before we go any further – let’s be clear: non-steroidal 5-AR inhibitors like saw palmetto, pumpkin seed oil, rosemary extract, and ecklonia cava still directly reduce 5-alpha reductase.
For example…
Non-Steroidal 5-AR Inhibitors: Direct Mechanisms
Pumpkin seed oil is high in polyunsaturated fatty acids (linoleic acid) and zinc. And interestingly, linoleic acid and zinc are non-steroidal elements which directly inhibit 5-alpha reductase. Here’s how:
Linoleic acid reduces 5-alpha reductase by altering the lipid bilayer in cell membranes. Conversely, zinc inhibits 5-alpha reductase by decreasing the expression of NADPH – the same cofactor needed for 5-alpha reductase to form.
These non-steroidal elements direct reduce 5-alpha reductase (5-AR). Why? Because they act on a molecular level to directly shut down 5-AR activity.
We see these same direct mechanisms are play with other natural DHT reducers – like saw palmetto and rosemary oil.
Saw palmetto extract inhibits 5-alpha reductase directly by competing with free testosterone to bind to androgen receptors. The more saw palmetto present, the less free testosterone can be converted to DHT. And just like saw palmetto, rosemary oil also appears inhibit 5-alpha reductase through direct actions on cell function.
But this isn’t the only way non-steroidal compounds reduce DHT levels. In fact, they also act on DHT indirectly… And evidence suggests that this type of DHT reduction – indirect – is probably much safer when it comes to sexual side effects.
Unlike Finasteride, non-steroidal 5-AR inhibitors like saw palmetto and pumpkin seed oil reduce DHT through both direct and indirect means.
As a refresher:
The definition of Indirect DHT Reduction is important – so let’s reinforce it.
Indirect DHT Reduction = Reducing Inflammation
When it comes to the causes of pattern hair loss, one question worth asking is…
If DHT levels are higher in balding scalps, then what causes DHT to rise in the first place?
Doctors have a simple answer for this: genetics. But the full story is a lot more complicated. For example, DHT may not just increase out of genetic sensitivity; DHT may increase, in part, as a response to chronic inflammation.
It’s far more likely that elevated scalp DHT in isn’t just due to genetic sensitivity, but rather, that this DHT is a response to inflammation in men’s scalp skin.
The causes of scalp inflammation are still debated, as is inflammation’s role in pattern hair loss. But one thing is clear: where there’s chronic inflammation, there’s also often an increase to DHT levels.
The net: higher DHT levels are a response to chronic inflammation. And if we take away the inflammation, we may indirectly take away some DHT.
And that is how we might indirectly reduce DHT levels. We take away the sources of inflammation.
Interestingly, non-steroidal 5-alpha reductase inhibitors might partially do this…
There are hundreds of studies showing how substances inside pumpkin seed oil, saw palmetto, rosemary, and ecklonia cava can reduce inflammation (and thereby DHT levels).
Covering all of them would turn this 5,000-word article in 100,000. So instead, we’ll just give a highlight reel.
The following parts of pumpkin seed oil help reduce chronic inflammation:
This list could go on for pages. But you get the idea: natural DHT reducers don’t just reduce 5-alpha reductase… They also reduce the signaling proteins and enzymes that are linked to chronic inflammation in our scalp tissues. As a result, they directly reduce inflammation, and thereby indirectly reduce DHT levels.
And that might be the difference between Finasteride and natural DHT reducers: one does more to directly reduce DHT levels; the other does more to indirectly reduce them. This, maybe the natural DHT reducers cause fewer sexual side effects… simply because these compounds are indirectly reducing DHT by lowering inflammation.
Again, these are just hypotheses. Nobody really knows.
When it comes to Finasteride, there is one study that has (slightly) worried me, and that I can’t fully explain.
Finasteride, when combined with Letrozole (a drug that lowers estrogen levels), appears to increase androgen receptor activity in the prostate of gerbils. That’s not necessarily a big deal… but it’s also not the whole story. In that study, the change in androgen receptor activity didn’t go away… even after stopping Finasteride + Letrozole treatment.
Why is this a problem? Well, if this research translates to humans, that would imply that when you get off Finasteride (Propecia), your prostate may have remodeled to have an even higher amount of androgen receptors. DHT has a higher affinity for androgen receptors than many other testosterone derivatives. Because of this, there’s a chance that if you increase your androgen receptors, the more likely DHT will arrive to those sites.
In other words, if your prostate remodels and you get off Finasteride, your prostate is likely going to flood with more DHT than if you never took Finasteride to start. This may, in part, explain things like the development of androgen-independent prostate cancer.
We don’t know, but hypothetically it’s possible. Maybe it’s even plausible.
In fact, this would explain why men lose hair so rapidly after dropping Propecia. More DHT floods the scalp and the hair rapidly miniaturizes… potentially sending people lower than their baseline (i.e., had they never started treatment in the first place).
Again, we just don’t know if these findings in gerbil prostates apply to humans with pattern hair loss, or if androgen remodeling with Finasteride + Letrozole is similar to that which might occur with Finasteride alone. Moreover, those gerbils were taking 10mg/kg of Finasteride – the equivalent of 720mg of Finasteride daily for humans. That feels like a supraphysiological amount for humans, and so it’s very possible that these study results do not apply to humans.
In any case, they do warrant more investigation, and maybe slightly more cause for concern among people considering the drug.
The answer to this question is that we don’t know.
While saw palmetto has been shown to not influence androgen receptor activity, there are no other studies (to my knowledge) that have evaluated this issue. But what’s assuring is that food-based DHT blockers…
Both of these likely lower the risk of irreversible tissue remodeling.
Moreover, natural DHT reducers have other health benefits besides promoting hair growth – like reducing oxidation and chronic inflammation – processes not only detrimental to our hair, but to our entire body. And if you’ve been keeping up with these articles, you’ll know how just how closely these processes are associated with nearly all disease development.
They’re not very effective. But if going all-natural is very important to you, than you can certainly try them.
Based on the evidence, “natural” DHT blockers – saw palmetto, pumpkin seed oil, rosemary oil, and ecklonia cava – seem to be somewhat effective at reducing DHT. They’re also derived from food substances as opposed to chemically altered steroids – which might make them safer (again, we just don’t know for sure).
For instance, drugs like Propecia appear to have no other benefits to cardiovascular health or longevity. Conversely, studies show that the substances inside “natural” DHT reducers may have anti-inflammatory properties that confer to longer-term health benefits: a reduction of reactive oxygen species, lower levels of inflammation, and more.
You have hundreds of “natural” DHT reducing supplements from which to choose. So, which are the best? We don’t yet know. What we do know is that these things aren’t as powerful as Finasteride… at least in their current formulations.
You could try saw palmetto, pumpkin seed oil, rosemary extract, peppermint oil, castor oil, olive oil, and just about every essential oil out there. All of these appear to have some anti-androgenic effects. At the same time, just because something is natural doesn’t make it safe.
If you do decide to try a “natural” DHT reducer – commit to it for at least six months before determining if it’s helping your hair loss. Better yet, do it in conjunction with mechanical stimulation exercises. Chances are the two will create a synergistic hair regrowth effect (read the case study in our saw palmetto article).
Questions? Comments? Please reach out in the discussion section.
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