If you have been told your testosterone is low, the most common thing a clinic will offer you is testosterone. A gel, a cream, or an injection that puts the hormone straight into your body. It works for the symptoms. It also quietly does something most men are never warned about: it can shut down your ability to have children.
This is one of the most preventable causes of male infertility we see, and it comes up constantly. A man in his 30s gets put on testosterone replacement for low energy or low libido, feels better, and only discovers years later, when he and his partner start trying for a baby, that his sperm count has fallen to near zero. Enclomiphene is a treatment that sits in exactly this gap. It raises testosterone by a completely different route, one that keeps sperm production running instead of switching it off.
It is also surrounded by a lot of noise. Telehealth companies market it aggressively, and the claims often run ahead of the evidence. So here is our honest read on what enclomiphene actually is, how it works in plain terms, what the research does and does not show, and who it genuinely helps.
What enclomiphene is
Enclomiphene is a selective estrogen receptor modulator, which is a class of drug that blocks estrogen from acting in specific places in the body. If that sounds like an odd thing to give a man who wants more testosterone, stay with us, because the logic is the whole point.
It is closely related to a much older drug called clomiphene, which has been used off-label in men for decades to raise testosterone and improve fertility. Clomiphene is actually a mixture of two mirror-image molecules, called isomers. One of them, enclomiphene, is the part that does the useful work of stimulating the hormonal system. The other, zuclomiphene, lingers in the body for weeks and is thought to be responsible for many of the estrogen-like side effects some men get on clomiphene. Enclomiphene is simply that first, useful isomer isolated on its own (Saffati et al., Translational Andrology and Urology, 2024).
How it works, in plain English
To understand enclomiphene you need a quick picture of the chain of command that runs male hormones. Your brain sits at the top. A region called the hypothalamus sends a signal to the pituitary gland, and the pituitary responds by releasing two messenger hormones into the blood: LH and FSH. LH tells the testes to make testosterone. FSH supports the machinery that makes sperm. This whole chain is often called the HPG axis, and the simplest way to think about it is that the brain tells the pituitary what to do, and the pituitary tells the testes what to do.
The system has a thermostat. When estrogen levels in the blood are high, the brain reads that as a signal that there is plenty of hormone around, and it dials down its signals. Less signal from the brain means less LH and FSH, which means less testosterone and less support for sperm. Men make estrogen too, by converting some of their testosterone into it, so this feedback loop is always running in the background.
Enclomiphene works by blocking the estrogen sensors in the brain. The brain can no longer sense the estrogen that is telling it to slow down, so it assumes levels are low and pushes harder. It sends out more signal, the pituitary releases more LH and FSH, and the testes respond by producing more testosterone and continuing to make sperm. You are not adding testosterone from outside. You are turning the body's own production back up.
That distinction matters more than almost anything else in this article, because it explains the fertility difference. The testosterone that actually drives sperm production is not the testosterone in your bloodstream. It is the testosterone concentrated inside the testes, at levels roughly 50 to 100 times higher than what a blood test measures. Sperm cannot develop without that intensely high local concentration. Enclomiphene keeps the testes switched on, so that internal concentration stays high and sperm production continues. We cover this in more detail in our article on what your testosterone level actually tells you.
Standard testosterone replacement does the opposite. When you put testosterone into the body from outside, the brain senses high levels and shuts the chain down. LH and FSH fall toward zero. The testes stop being told to work, the high internal testosterone concentration collapses, and sperm production fails, even though the testosterone level on your blood test looks perfectly normal. That is why testosterone therapy and fertility so often pull in opposite directions. Major urology guidelines are explicit that testosterone should not be given to men who are currently trying to conceive (Mulhall et al., Journal of Urology, 2018).
What the research shows
The evidence for enclomiphene is genuinely encouraging on the two things it was designed to do: raise testosterone and preserve sperm. It is thinner, and we want to be upfront about this, on the question that matters most to couples, which is whether it actually helps them have a baby.
The core comparison came from a set of trials that put enclomiphene head to head with testosterone gel. In a combined analysis of two phase III trials involving around 256 overweight men with low testosterone, enclomiphene raised average testosterone from roughly 205 into the low 400s of nanograms per deciliter, comfortably back into the normal range. Crucially, it did this while LH and FSH went up, and sperm concentration rose modestly, by around 12 to 15 percent. The men treated with testosterone gel also saw their testosterone rise, but their LH and FSH were suppressed and their sperm concentration fell sharply, by somewhere in the range of a third to more than half. Same goal of restoring testosterone, opposite effect on fertility (Kim et al., BJU International, 2016). Earlier trials found the same pattern, with enclomiphene raising testosterone within about two weeks while preserving sperm counts that topical testosterone reduced (Wiehle et al., Fertility and Sterility, 2014).
The most complete recent picture comes from a 2025 systematic review and meta-analysis in Archives of Endocrinology and Metabolism, which pooled 10 randomized controlled trials covering 819 patients. One caveat to be clear about: this analysis looked at the whole class of these drugs, meaning clomiphene and enclomiphene together, not enclomiphene on its own. It found that these drugs raised total testosterone by an average of about 274 nanograms per deciliter compared with placebo. Compared against testosterone gel, they produced no meaningful difference in testosterone levels, but they delivered significantly higher LH and FSH and significantly better sperm concentration (Archives of Endocrinology and Metabolism, 2025). In other words, for raising testosterone, enclomiphene and a gel get you to a similar place. For doing it without harming fertility, enclomiphene wins clearly.
What we are more skeptical about
Two claims get made about enclomiphene that the evidence does not currently support, and being straight about them is more useful than the marketing.
The first is the idea that enclomiphene is proven to help couples conceive. It is not, at least not yet. The trials measured hormones and sperm concentration, which are the raw materials of fertility, but they did not measure pregnancies or live births. Whether restoring testosterone and preserving sperm counts with enclomiphene translates into more babies is a reasonable expectation, but it has not been demonstrated in a proper trial. Pregnancy depends on many things beyond a single sperm number, including the female partner and the timing, so we hold this one loosely and you should too.
The second is the idea that enclomiphene is clearly better than plain clomiphene, which is far cheaper. The theory is appealing, since enclomiphene strips out the long-lingering isomer that causes side effects. But when researchers actually compared them, the testosterone increase was about the same, and the main measurable advantage for enclomiphene was a smaller rise in estradiol, which is the main form of estrogen, and somewhat fewer reported side effects (Saffati et al., Translational Andrology and Urology, 2024). That is a real and reasonable advantage for some men, but it is not the same as being a more effective fertility treatment, and no head to head trial has shown enclomiphene produces better fertility outcomes than clomiphene.
There is also a simple honesty point about approval. Enclomiphene is not approved by the FDA for male infertility or for low testosterone. Its manufacturer pursued approval years ago and the FDA declined, asking for more evidence, and the program was eventually dropped. What you can get today is almost always prepared by a compounding pharmacy and prescribed off-label (Drugs.com, Androxal history). That does not make it useless, and off-label prescribing is common and legitimate in medicine, but you should know that this is not a drug that cleared the standard approval bar for this use.
Who it is most relevant for
Enclomiphene fits a specific man well, and being specific here matters. The best candidate is a younger man with low testosterone whose problem is coming from the signal, not the testes themselves. In practice that means low testosterone alongside LH and FSH that are low or in the normal range rather than elevated, a pattern doctors call secondary hypogonadism. It suggests the testes are capable of working, they are just not being told to loudly enough. Enclomiphene turns up the volume on that signal. The men in the main trials were largely in this group, often carrying extra weight, which is one of the most common reasons the signal gets suppressed in the first place.
The most important part of the fit is intent. If you want the benefits of higher testosterone but you also want to keep the option of having children, whether now or in a few years, enclomiphene is designed for exactly that situation. It is the difference between restoring your own system and replacing it. Guidelines that address fertility in men with low testosterone specifically point to this class of drug, along with a few related options, for men who want to preserve fertility (AUA/ASRM Male Infertility Guideline, 2021).
Who it will not help
Enclomiphene works by shouting louder at the testes, so it only helps if the testes can still hear and respond. When the problem is in the testes themselves, that shouting achieves nothing. Men with what is called primary testicular failure already have high LH and FSH, because the brain is already pushing as hard as it can and the testes still cannot keep up. Pushing harder with enclomiphene does not fix a testicle that has lost the ability to produce. This is the pattern seen in conditions like Klinefelter syndrome or after certain chemotherapy, and it is exactly why testing your hormones as a set, rather than looking at testosterone alone, is what tells you whether enclomiphene has any chance of working.
It is also not the right tool for a man who simply wants his testosterone normalized as fast as possible and has no interest in fertility. For that person, standard testosterone therapy is straightforward and effective. Enclomiphene earns its place specifically when fertility is on the table.
How it fits into the bigger picture
The thread running through all of this is that you cannot make a sensible decision about enclomiphene without knowing your numbers first. The single most useful thing you can do is measure testosterone alongside LH and FSH, and ideally estradiol, together with a full semen analysis. That combination is what tells you whether your low testosterone is coming from the signal or the testes, whether enclomiphene is even a candidate, and where your fertility stands before you change anything.
It matters just as much afterward. Because a full cycle of sperm production takes around 72 days, any effect on your semen parameters takes at least 12 weeks to show up, and clinicians usually recheck testosterone, LH, FSH and estradiol along the way to confirm the treatment is doing what it should. This is treatment that needs monitoring, not a supplement you take and forget. Reliable monitoring depends on lab-grade results, which is why it is worth understanding what a CLIA-certified lab is and why it matters for numbers you are going to base real decisions on.
A SwimScore panel is built for exactly this: it measures FSH, LH and testosterone alongside a full semen analysis and DNA fragmentation, from CLIA-certified labs and against WHO 6th Edition thresholds, in one report you can take to a clinician. Whether you are weighing up testosterone therapy, considering enclomiphene, or just want a clear baseline before anything, that is the picture worth having.
Our take
Enclomiphene is one of the more genuinely useful ideas in male hormonal health, because it solves a real and common problem. Too many men are put on testosterone that fixes their symptoms while silently costing them their fertility, and enclomiphene offers a way to raise testosterone that keeps the system, and sperm production, running. On that specific promise, the evidence is solid: it reliably raises testosterone, it keeps LH and FSH up, and it preserves sperm counts where a gel would crush them.
What we would not do is oversell it. It is not FDA-approved for this use, it has not been proven to increase pregnancies, and it is not clearly superior to the older, cheaper clomiphene on the outcomes that count. It is a prescription treatment that needs a clinician and ongoing monitoring, not a shortcut. Used in the right man, for the right reason, and measured properly before and after, it is a smart option. The move is the same as always. Know your numbers, understand what is driving them, choose the treatment that fits your goals including fertility, give it at least 12 weeks, and measure again to see what actually changed.
Are you a clinician? SwimScore partners with men's health and fertility clinics to provide CLIA-certified semen analysis and hormone testing your patients can complete at home. Learn more on our For Clinics page.
This article is for general education and is not medical advice. Enclomiphene is a prescription medication used off-label, and decisions about it should be made with a qualified clinician.
SwimScore uses CLIA-certified labs for all semen analysis and hormone testing, assessed against WHO 6th Edition clinical thresholds.
