By John Goss, Founder of Adegen
I've spent 25 years researching hair loss. I've worked with some of the best experts in the world, from dermatologists and research chemists to compounding pharmacists. I eventually built my own pharmacy so I could do this the right way.
And in all that time, I've seen one fear stop more people from treating their hair loss than anything else.
Not the cost. Not the inconvenience. Not the daily commitment.
The fear of sexual side effects from finasteride. And dutasteride, the more effective alternative that I personally take.
I understand it. I had it too. And I want to talk about it honestly, because the conversation happening out there is doing real harm. The fear is dramatically outsized relative to the actual risk. And there is something you can add to your protocol that addresses what little risk exists while delivering a wide and impressive range of health benefits on top of that.
If you came here from [I Was Terrified of Finasteride. Then I Read the Actual Studies], you already have the full picture on the real numbers.
Knowing the numbers helps. But data does not always dissolve a fear that has been building for months or years. If you are still uneasy, that is not irrational. It makes you human. This article is about what I actually do about it, and why it changed how I think about the whole equation.
The Quick Reality Check
I am not going to ask you to take a pharmaceutical company's word for this alone. The strongest evidence comes from government-funded trials, independent academic institutions, and large-scale meta-analyses that have nothing to do with the companies that make these drugs.
The largest independent long-term trial ever conducted on finasteride tracked 17,313 men for seven years at five times the standard hair loss dose. The independent researchers concluded the effect on sexual function "is minimal for most men and should not impact the decision to prescribe or take finasteride." For context, age alone reduces that same score by 1.26 points per year. The medication produces less cumulative impact over seven years than three years of simply getting older.
The largest population study ever conducted on this question covered 2.2 million patients across five independent studies. Researchers found no statistically significant association with depression, and no statistically significant association with suicide.
The absolute difference over placebo in the largest controlled hair loss trials is 1.7 percentage points. That is the only number that actually tells you what you personally are likely to experience. By year five of treatment, reported rates fall to 0.3% or less. Side effects decrease the longer you stay on it.
And then there is the nocebo effect, which almost nobody talks about.
A randomized trial published in the Journal of Sexual Medicine gave 120 men the exact same medication at the exact same dose. One group was told about potential sexual side effects. The other was not. The informed group reported sexual side effects at 43.6%. The uninformed group reported them at 15.3%. Same drug. Same dose. Being told about possible side effects nearly tripled the reporting rate.
The only difference was expectation. If you have spent hours reading forum posts and Reddit threads before starting treatment, that exposure itself becomes a variable. The pharmacology of the drug is not the only thing acting on you.
A significant amount of the fear-based content online is not coming from scientists or real patients sharing honest experiences. It is coming from people selling "all natural" hair loss supplements and other products they know are less effective. They cannot offer you what actually works, so their business model depends on making you afraid of what does. We have even had companies steal our own before and after photos and use them in ads for their inferior products. That tells you something about the incentives at play.
For the complete breakdown of every major study, I cover it all in [I Was Terrified of Finasteride. Then I Read the Actual Studies].
Here Is What I Actually Do About It
Even with all this data, some people are still going to feel uneasy. And I get it. The fear is real, even when the risk is small.
So here is what I want you to know. There is something you can add to your protocol that does not just reduce what little risk exists. It works in the exact opposite physiological direction from the theoretical mechanism behind these side effects, and it delivers a wide and impressive range of health benefits on top of that.
I take it. I think more people on hair loss treatment should know about it.
The Daily Addition That Changed How I Think About This
I take low-dose tadalafil daily.
Most people know tadalafil as Cialis, the erectile dysfunction drug. That framing has buried something important about what it actually does.
Tadalafil is a PDE5 inhibitor. Here is what that actually means in plain language. When you are aroused, your body releases nitric oxide, which triggers the production of a molecule called cGMP. That molecule relaxes smooth muscle tissue and allows blood vessels to widen, increasing blood flow. PDE5 is the enzyme that breaks cGMP down and ends that process. Tadalafil works by blocking PDE5, which means cGMP stays active longer and blood flow remains elevated. This is why it was originally developed for cardiovascular and prostate conditions before it became known as an ED drug.
The mechanism is fundamentally about blood flow, not sexuality.
Because restricted blood flow to the hair follicle is also at the root of why hair loss progresses in the first place, tadalafil works by increasing blood flow systemically while the theoretical concern around finasteride's side effects involves reduced blood flow in a specific area. These two things point in exactly opposite directions, and understanding that changes how you think about the whole protocol.
Andrew Huberman covered this in detail in a recent podcast, specifically noting that tadalafil gets lumped into the sexual performance category in a way that completely overlooks its broader roles in men's health. He also pointed out that NFL players and Olympic athletes take it before games to lower blood pressure and increase peripheral blood flow. That alone tells you something about its profile.
Here is why this matters for anyone on hair loss treatment.
The theoretical mechanism behind finasteride's sexual side effects involves reduced blood flow and reduced sensitivity. Tadalafil does the exact opposite. Adding it to your protocol is not just a psychological hedge. It is a physiological one.
And the benefits extend well beyond that.
Cardiovascular health. A 2024 study published in the American Journal of Medicine analyzed data from more than 50 million men and found that daily low-dose tadalafil was associated with a 34% reduction in mortality, 27% fewer heart attacks, 34% fewer strokes, and 32% lower rates of dementia compared to men not taking it. A separate 2024 study in Clinical Cardiology covering 29,000 men found similar results, with the strongest effects in men with the highest cumulative exposure. These are large observational studies, not causal proofs, but the consistency of the signal across very large populations is hard to ignore.
Prostate health. This was its original clinical application. Regular low-dose use supports prostate blood flow and can help with urinary symptoms, which is particularly relevant given that the medications used in hair loss also affect the prostate. The pairing makes clinical sense.
Exercise performance and recovery. Better peripheral blood flow means better oxygen delivery to muscle tissue. This is why elite athletes use it. Not for aesthetics. For performance and recovery.
Mood and energy. Improved cardiovascular function and systemic blood flow tend to have downstream effects on daily energy and how you generally feel.
Sexual confidence. If you are concerned about potential side effects from finasteride or dutasteride, knowing you have a daily medication working in the opposite direction removes significant psychological friction. And given what the nocebo data shows, that reduction in anxiety may itself reduce reported side effects.
Put those together and something interesting emerges. You are not just neutralizing a small theoretical risk. You are potentially coming out healthier than you started. That is not a defensive move. That is an upgrade.
The Protocol I Settled On
After years of research, here is what I take: dutasteride for the treatment side, and low-dose tadalafil daily as what I think of as the insurance policy with upside.
Dutasteride because it is meaningfully more effective at suppressing DHT than finasteride, with a comparable or better side effect profile. I cover the full comparison in [The Drug That Works Better Than Finasteride and Why You've Never Heard of It]. For the purposes of this article, what matters is that whichever one you choose, the tadalafil addition works the same way.
It is not a stack of random pills. It is a considered system built from clinical evidence, designed to treat hair loss aggressively while simultaneously upgrading cardiovascular and metabolic health.
That is the protocol I built for myself, and it is the framework I think more men should be aware of when they are weighing their options.
The evidence is clear, the risk is small, and the right protocol does not just manage that risk. It turns the whole equation into something worth doing for reasons that have nothing to do with hair.
The fear is understandable. But it no longer needs to stop you.
If you want to find out which protocol is right for your specific situation, our HairIQ 60-second Hair Assessment is the best place to start. It will tell you exactly which approach is best suited for you personally.
Sources: Moinpour et al. (2007), Prostate Cancer Prevention Trial, Journal of the National Cancer Institute; Uleri et al. (2024), European Urology Focus; PLESS Trial; Kaufman et al. (1998), Merck Phase III trials; Mondaini et al. (2007), Journal of Sexual Medicine; von Kuenssberg Jehle et al. (2024), American Journal of Medicine; Kloner et al. (2024), Clinical Cardiology; Andrew Huberman, podcast interview.
