02· Hormones · men

Your own testosterone. Decided on your labs.

Enclomiphene is an oral medicine studied for secondary hypogonadism: low testosterone caused by a weak signal from the brain and pituitary rather than by the testes themselves. It prompts your own production instead of replacing it, which is why men who want to keep their fertility, or who would rather not inject, ask about it; it is not FDA-approved, and it is not right for everyone.

Book a doctor visit How it works

Prescription required. A licensed provider decides whether treatment is appropriate.

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At a glance

Oral, dailyPrescription only

Not FDA-approvedCompounded by a 503A pharmacy

Two morning labsDecide it, and review it

What it is

Your own testosterone, switched back on.

Enclomiphene is one of the two isomers that make up clomiphene citrate, the ovulation tablet used in women for more than fifty years. The trans-isomer, enclomiphene, is the part that blocks estrogen's feedback on the brain; the cis-isomer, zuclomiphene, is a weak estrogen that clears slowly. Giving enclomiphene on its own was developed as a cleaner way to raise LH, FSH and testosterone in men whose testes still work.

It went through phase 3 trials as Androxal, but the FDA declined to approve it in 2015 and the European regulator refused it in 2018 because, in the regulators' view, the trials showed higher testosterone without demonstrating a clinical benefit. It is not FDA-approved for any use. In the US it is available only as a compounded medicine: if a clinician prescribes it, a state-licensed 503A compounding pharmacy prepares it in your name and ships it sealed. Compounded medicines are not reviewed by the FDA for safety, effectiveness or quality.

The honest line

Not FDA-approved. The trials showed it raises testosterone; they did not measure whether men felt better. We say so.

01Prescription only. A licensed clinician decides whether it is appropriate for you.

02Prepared for you by a US state-licensed 503A pharmacy, in your name.

03Reviewed on a schedule, with labs. Changed or stopped on evidence.

How it works

How it works, in three moves.

A selective estrogen receptor modulator: it changes what the brain hears, and the brain answers.

Blocks estrogen feedback

Enclomiphene occupies estrogen receptors in the hypothalamus and pituitary, so the brain stops reading estrogen as a reason to hold back.

LH and FSH rise

The pituitary releases more LH and FSH. LH tells the testes to make testosterone; FSH supports sperm production.

The testes respond, if they can

Testosterone rises from your own Leydig cells and sperm production carries on. If the testes themselves have failed, LH is already high and a stronger signal has nowhere to go.

Who it is for

Who it is prescribed for.

A clinician decides on your history, your symptoms and your labs. These are the situations it is usually considered for.

01
Low testosterone with a low or normal LH
Two early-morning total testosterone values below about 300 ng/dL, symptoms that fit, and an LH that is low or inappropriately normal: the pattern of secondary hypogonadism.
02
Men who want to keep their fertility
Testosterone therapy suppresses sperm production, sometimes for a long time. The AUA guideline lists SERMs among the options for men with testosterone deficiency who want to maintain fertility.
03
Men who prefer an oral option
A daily capsule rather than injections or gels, with no risk of transferring testosterone gel to a partner or child.

Not the right fit when

Primary testicular failure (high LH and FSH): the testes cannot answer a stronger signal.
A history of prostate cancer or male breast cancer, or an unexplained raised PSA.
Liver disease, now or in the past.
A pituitary tumor or other intracranial lesion; uncontrolled thyroid or adrenal disease.
A history of blood clots (DVT or pulmonary embolism) or a known clotting disorder.
Normal testosterone: enclomiphene is not a performance, muscle or 'wellness' product.
Men under 18, and anyone without two proper early-morning tests.

Your clinician goes through this with you on the visit. Some histories rule it out; if yours does, you are told plainly and offered what they would look at instead.

The visit

What your clinician looks at.

A real visit by video, usually within minutes of starting. They ask, you ask, and they decide whether treatment is appropriate. Sometimes the answer is no.

Book a doctor visit

Prescription required. A licensed provider decides whether treatment is appropriate.

01
Two morning tests
Total testosterone drawn before 10 am on two separate days, ideally fasting, with LH and FSH to show whether the problem is upstream (low or normal LH) or in the testes (high LH).
02
The wider panel
Estradiol, prolactin, SHBG and free testosterone where the total is borderline, a blood count for hematocrit, PSA for men over 40, and liver function. A high prolactin or a very low testosterone prompts pituitary imaging before anything else.
03
Your history
Symptoms and how long, sleep and sleep apnea, weight, alcohol, opioids and other medicines, past steroid or testosterone use, mood, plans for children, and any eye, liver, clot or prostate history.

How it is taken

A daily tablet, adjusted on labs.

01
One capsule a day
Most men start at 12.5 mg daily. In the phase 3 trials the dose was raised to 25 mg if testosterone had not reached the target range by week 4.
02
Labs again at six to eight weeks
Testosterone, LH, estradiol and hematocrit are rechecked, and the dose is adjusted on those numbers, not on how you feel alone.
03
Reviewed, then reviewed again
If testosterone normalises but symptoms have not improved within three to six months, the plan changes or stops. If it is working, labs continue every six to twelve months. Because it does not switch off your own production, stopping it does not leave the axis suppressed the way stopping testosterone can.

What to expect

What happens, and when.

01
Weeks 2 to 6
In the trials, LH, FSH and total testosterone rose within two weeks and were in the normal range by six weeks in most men on 12.5 to 25 mg.
02
Months 1 to 3
If symptoms are going to change, energy, libido or mood, this is the window. The enclomiphene trials measured hormones, not symptoms; the symptom evidence comes from clomiphene cohorts and from clinical experience.
03
Sperm and estradiol
Sperm concentration stayed in the normal range over 16 weeks in the phase 3 trials, while it fell markedly on testosterone gel. Estradiol rises alongside testosterone and is watched; breast tenderness is the sign it has risen too far.

Side effects, plainly

What it can feel like.

Most people have none of these, some have one or two, and your clinician tells you what to watch for.

Headache

The most frequently reported effect across the trial programme, usually mild.

Hot flushes

Reported by a small share of men, as with other SERMs.

Nausea, muscle cramps, dizziness

Reported by a few percent of men in the trial programme; the European review listed headache, hot flushes, nausea and muscle spasms as the most frequent effects.

Mood changes

Anxiety, irritability or low mood were reported in a few men in the trials and in clomiphene cohorts. Tell your clinician early.

Visual disturbance

Blurred vision led some men in the trials to stop, and the SERM class carries a rare risk of eye effects. Any blurring, spots or flashes: stop and call the same day.

Estradiol, hematocrit and PSA

Each can rise. A raised hematocrit or PSA led to discontinuation in the phase 3 trials, which is why they are checked before and during treatment.

Blood clots

The European regulator cited a possible risk of venous thromboembolism, and a small number of clot events were reported among about 500 men in the 26-week safety study. A history of clots rules it out.

This is not a complete list. Your clinician goes through the risks that apply to you before anything is prescribed, and is a message away if something does not feel right.

The evidence

What the research actually shows.

In two 16-week phase 3 trials (ZA-304 and ZA-305; 256 men with secondary hypogonadism), enclomiphene 12.5 to 25 mg raised total testosterone, LH and FSH from baseline and maintained sperm concentration in the normal range, whereas testosterone gel raised testosterone but markedly reduced sperm production.¹¹¹⁴
In a three-month phase 2 trial (124 men), total testosterone rose from about 217 to 471 ng/dL on 12.5 mg and from 209 to 405 ng/dL on 25 mg, comparable to testosterone gel (210 to 462), while the share of men with a low sperm concentration rose from 16% to 53% on gel and did not rise on enclomiphene.¹²²²
The FDA declined to approve enclomiphene (Androxal) in December 2015, stating that the phase 3 design was no longer adequate to demonstrate clinical benefit; the European Medicines Agency refused it in 2018 because symptoms were not assessed and citing a venous thromboembolism risk; and in June 2022 an FDA advisory committee voted 8 to 4 against adding it to the list of substances permitted for 503A compounding, noting that no trial had measured symptom improvement.¹⁴¹⁵¹⁶
A 2025 meta-analysis of randomised trials found that clomiphene or enclomiphene raised total testosterone by a mean 274 ng/dL against placebo, with no significant difference from testosterone gel; in a 2024 comparison of 66 men who had taken both, enclomiphene produced a smaller estradiol rise and fewer reported side effects than clomiphene.¹⁹²⁰

Compounded medications are prepared by US state-licensed 503A pharmacies for individual patients on a prescription; they are not FDA-approved. Availability varies by state.

Sources

FDA status

Enclomiphene is not FDA-approved for any use (the FDA declined the Androxal application in 2015 and no enclomiphene product has been approved since), and in the US it is available only as a compounded medicine prepared on prescription by a licensed compounding pharmacy; compounded drugs are not reviewed by the FDA for safety, effectiveness or quality.

Questions

Asked often.

Anything about your own health is answered by a licensed clinician on a visit, not here.

Is enclomiphene FDA-approved?

No. It was studied as Androxal, the FDA declined to approve it in 2015, and the European regulator refused it in 2018. It is prescribed off-label and prepared by a compounding pharmacy, which means the FDA has not reviewed the product you receive.

How is it different from clomiphene?

Clomiphene is a mix of two isomers; enclomiphene is the one that raises LH and FSH, without the slow-clearing, weakly estrogenic zuclomiphene. Both raise testosterone; head-to-head data are thin. Clomiphene is FDA-approved (for women) and has more long-term data in men; enclomiphene has less evidence overall, though one small study found a smaller estradiol rise and fewer side effects.

How is it different from TRT?

Testosterone therapy replaces the hormone and switches off your own production, including sperm. Enclomiphene asks your testes to make more. TRT has decades of outcome data and FDA-approved products; enclomiphene has hormone data from short trials and no symptom trials. For a man with primary testicular failure, only TRT works.

Will it improve my symptoms?

The honest answer: the trials showed it raises testosterone; they did not measure whether men felt better. Evidence that symptoms improve comes from clomiphene cohorts, where about three in four men reported improvement. If your testosterone normalises and nothing else changes within three to six months, we stop.

Will it affect my fertility or my sperm?

In the phase 3 trials, sperm concentration stayed in the normal range on enclomiphene and fell markedly on testosterone gel. It is not a fertility treatment, though, and a man trying to conceive should have a reproductive evaluation first.

Why might the answer be no?

Because your testosterone is normal, your LH is high (the problem is in the testes), you have a history of clots, liver disease, prostate or breast cancer, or because your labs point to a pituitary cause that needs imaging before anything else. Sometimes the answer is no, and we tell you why.

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