Enclomiphene Side Effects: What the Research Shows and What to Watch For
Last Updated November 2026
Let’s be real. Most men don’t research a new medication by reading about the benefits. They go straight for the scary stuff. If you’re thinking about starting enclomiphene, there’s a good chance you’ve already searched for enclomiphene side effects late at night and found a mix of forum horror stories and vague answers.
So let’s clear the air. This guide covers what the research actually reports, which side effects come up most, which lab changes your provider will watch, and which signs mean you should pick up the phone. No hype, and no scare tactics.
Quick answer: In the clinical trials reviewed by researchers, most reported enclomiphene side effects were mild, with headaches named most often. In one large trial, the rate of side effects did not differ from placebo. Estradiol (a form of estrogen) can rise, so providers track it with bloodwork, and any vision changes should be reported to your provider right away.
Why Enclomiphene Side Effects Worry So Many Men
Enclomiphene belongs to a group of medications called selective estrogen receptor modulators, or SERMs. Instead of adding testosterone from the outside, it signals your body to make more of its own. If you want the full background, start with What Is Enclomiphene?
A lot of the worry comes from its close relative, clomiphene, better known as Clomid. Clomid’s side effect list is well known, and enclomiphene often gets lumped in with it. We break down how the two differ in Clomid vs. Enclomiphene for Low Testosterone.
Use is also growing. A 2025 research review noted that off label use of SERMs for men with low testosterone has increased, which means more men are asking the same questions you are:
- Will it mess with my mood?
- Could it affect my vision?
- Will my estrogen spike?
- What happens if I stay on it for a long time?
Fair questions, all of them. Let’s look at what the evidence says, and where it still has gaps.
What the Research Shows About Enclomiphene Side Effects
The most useful summary comes from a 2025 systematic review and meta analysis published in Archives of Endocrinology and Metabolism. The authors pooled randomized trials of clomiphene and enclomiphene in men. Here’s what they reported from the two enclomiphene trials:
Table 1. Reported enclomiphene side effects in two clinical trials
| Trial | Enclomiphene doses | What researchers reported |
| Kim, 2016 | 12.5 mg and 25 mg | 53 men (21%) had side effects possibly linked to the drug. None were severe, and the rate of side effects did not differ from placebo. |
| Wiehle, 2014 | 12.5 mg, 25 mg, and 50 mg | Side effects showed up in 9% to 20% of participants and were similar across groups. Examples included mild sinus headache and moderate headache. No side effects caused anyone to stop, and there were no serious side effects in the enclomiphene group. |
In plain English: the side effects researchers named were mostly headaches, and in the larger trial the overall rate looked a lot like placebo. The review also noted:
- No blood clots were reported in men taking enclomiphene.
- None of the included studies reported a drop in sex drive or erections.
- Across all the SERM trials, the authors saw no substantial adverse events overall.
Now the honest part. The authors said their analysis “remains underpowered with regard to safety endpoints,” which means the trials weren’t big enough to rule out rarer problems. Vision changes and mood also weren’t measured as outcomes in the enclomiphene trials. That’s no reason to panic, but it is a good reason to start with a provider who keeps an eye on you.
Estrogen and the Lab Changes Your Provider Watches
Estrogen is the side effect men ask about most. When your body makes more testosterone, some of it naturally converts into estradiol, a form of estrogen. In the 2025 review, men taking SERMs had higher estradiol on average than men in the comparison groups:
Figure 1. Average difference in estradiol for men taking SERMs (clomiphene or enclomiphene). Source: 2025 review.
That sounds like a lot, but context matters. The authors noted the rise did not appear to harm sexual function. Still, estrogen that runs too high is worth catching early, which is one reason bloodwork matters. If you’ve wondered about estrogen blockers, we cover the topic in Should You Take Anastrozole with Testosterone?
Here are the main lab markers worth knowing:
Table 2. Lab markers to monitor on enclomiphene
| Lab marker | What it tells you | What the 2025 review found |
| Estradiol | Your level of estrogen | Rose on average in men taking SERMs |
| Hematocrit | The share of your blood made up of red blood cells | The authors described the chance of hematocrit changes as low |
| PSA | A marker your provider uses to keep tabs on prostate health | One man taking 25 mg in the Kim trial stopped because of a high PSA reading |
| Testosterone | Whether your body is responding | Used across the trials to track how men responded |
Want to know how often labs usually happen? Our guide on how often you need blood work walks through a typical monitoring schedule.
Warning Signs and How Providers Keep Treatment on Track
Because enclomiphene is closely related to clomiphene, it’s smart to know the warning signs MedlinePlus lists for clomiphene. Most are mild. A few deserve a same day call.
Table 3. Side effects listed for clomiphene, a close relative of enclomiphene
| Usually mild (tell your provider if they don’t go away) | Uncommon but serious (call your provider right away) |
| Flushing or feeling warm | Blurred vision |
| Upset stomach | Spots or flashes in your vision |
| Headache | Double vision |
| Breast discomfort | Shortness of breath |
MedlinePlus also advises against driving, especially in poor lighting, until you know how clomiphene affects your vision. Bottom line: if your eyesight changes, don’t wait it out. Make the call.
Screening matters too. The enclomiphene trials excluded men with a history of blood clots and men with certain eye findings, including cataracts above a set grade. That’s exactly the kind of history a good provider asks about before you start. Here’s what solid, provider guided care looks like:
- Labs before you start, so there’s a baseline to compare against
- A full health history, including blood clots and eye health
- Follow up bloodwork for testosterone, estradiol, hematocrit, and PSA
- An easy way to report symptoms, so small issues don’t become big ones
- Dose adjustments based on your labs and how you feel
Fear is reasonable. Guessing is the problem. If you’re weighing whether enclomiphene fits your situation, you can answer a few quick questions to customize your treatment. Curious what the first appointment covers? Read What Happens During Your TRT Consultation? or browse more guides on the TRT Nation blog.
Frequently Asked Questions
What are the most common enclomiphene side effects?
Headaches were the side effect named most often in the trials summarized by a 2025 review, and most reported effects were mild. In one large trial, the rate of side effects did not differ from placebo. At TRT Nation, licensed providers review your symptoms alongside your labs so you can flag anything that bothers you.
Does enclomiphene raise estrogen?
It can. In a 2025 review, men taking SERMs had higher estradiol on average, though none of the included studies reported a drop in sex drive or erections. TRT Nation tracks estradiol in your bloodwork so your provider can respond if levels climb.
Can enclomiphene affect your vision?
Vision wasn’t measured as an outcome in the enclomiphene trials, but blurred vision, spots, flashes, and double vision are listed as uncommon but serious side effects of clomiphene, its close relative. If you notice any vision change, contact your provider right away. TRT Nation providers review new symptoms together with your labs throughout treatment.
Who should be careful with enclomiphene?
The clinical trials excluded men with a history of blood clots and men with certain eye findings, so those are important to discuss before starting. Your provider makes the call based on your full history and labs. TRT Nation starts every plan with lab testing and a provider review before any treatment decision.
Is enclomiphene safe long term?
Long term safety data is still limited, and the 2025 review noted that its analysis was underpowered for safety outcomes. That’s why ongoing bloodwork and check ins matter. TRT Nation covers what happens over time, including stopping, in Enclomiphene Long Term: What Happens If You Stop Treatment.