Clomiphene and Enclomiphene for Men: Raising Testosterone Without Hurting Sperm

Why testosterone therapy can stop sperm production

It sounds backwards: testosterone is the "male hormone," so how can more of it hurt sperm? The answer is the feedback loop between the brain and the testes, the hypothalamic-pituitary-gonadal (HPG) axis.

1. The pituitary gland releases LH, which tells the testes to make testosterone, and FSH, which supports sperm production.
2. Sperm production depends on a very high concentration of testosterone inside the testes, far higher than in the blood.
3. When testosterone comes from outside, as a gel, injection, or pellet, the brain senses plenty in the bloodstream and turns down LH and FSH.
4. With less LH, the testes make less of their own testosterone. Testosterone inside the testes falls, and with less FSH as well, sperm production can drop sharply or stop.

A 2023 case discussion in AUANews, the American Urological Association's news publication, describes exactly this: exogenous testosterone feeds back on the HPG axis, suppresses gonadotropin release, lowers testosterone inside the testes, and reduces sperm production.

The label for one widely used testosterone gel (AndroGel 1.62%) puts it in regulatory language. It warns that spermatogenesis may be suppressed "through feedback inhibition of pituitary FSH," and notes that testicular atrophy and oligospermia (low sperm count) have been identified during use. It also states that "the impact on fertility may be irreversible."

The same logic applies to anabolic steroids and many "gym" products. Our sister site has a detailed guide to gym supplements, SARMs, and sperm.

How clomiphene and enclomiphene work

Clomiphene and enclomiphene are selective estrogen receptor modulators (SERMs). In men, some testosterone is converted to estrogen, and estrogen is one of the signals the brain uses to decide it has "enough" and turn down LH and FSH.

SERMs block estrogen receptors in the hypothalamus and pituitary. The brain reads that as low estrogen and responds by raising LH and FSH. Higher LH tells the testes to make more of their own testosterone. Higher FSH supports sperm production. Instead of replacing testosterone from outside and shutting the system down, SERMs turn the body's own system up.

The AUANews discussion notes that SERMs, aromatase inhibitors, and hCG can all maintain normal testosterone production without impairing spermatogenesis. It also notes that regimens vary and aren't standardized, and that no FDA-approved therapy exists for male fertility. Every option discussed here is used off-label for that purpose.

Clomiphene: what the label says

Clomiphene citrate (brand name Clomid, among others) has been around for decades as a fertility drug for women. Its FDA-approved prescribing information says:

• Indication: "the treatment of ovulatory dysfunction in women desiring pregnancy." There is no approved use in men.
• On male infertility, the label says there are no adequate or well-controlled studies demonstrating effectiveness.
• Safety: it notes that testicular tumors and gynecomastia (breast tissue growth) have been reported in males using clomiphene.
• Composition: clomiphene is "a mixture of two geometric isomers": zuclomiphene (cis) and enclomiphene (trans). It contains between 30% and 50% of the cis isomer.

So when a urologist prescribes clomiphene to a man with low testosterone who wants to preserve fertility, that's an off-label use of an old, widely available drug. Off-label prescribing is legal and common. It means the FDA hasn't reviewed evidence for that specific use, so the prescriber's judgment and your monitoring matter more.

Enclomiphene: what's actually known

Enclomiphene is the trans isomer that makes up part of clomiphene. The two isomers in clomiphene don't behave identically. The rationale for isolating enclomiphene is that a single-isomer product could deliver the LH and FSH rise more predictably. Whether that turns into meaningful real-world advantages over clomiphene hasn't been settled by large trials.

The evidence

A randomized phase II trial published in Fertility and Sterility in 2014 (Wiehle and colleagues) compared oral enclomiphene with a 1% testosterone gel in men with secondary hypogonadism, meaning low testosterone with low or inappropriately normal LH. Enclomiphene raised morning testosterone to levels similar to the gel, increased LH and FSH, and preserved sperm counts. The paper's title summarizes it: enclomiphene "stimulates testosterone production while preventing oligospermia."

The regulatory status

• Not FDA-approved. The developer submitted a New Drug Application for enclomiphene (Androxal) in 2015. In December 2015 the FDA issued a Complete Response Letter, saying in part that the phase 3 study design was no longer adequate to demonstrate clinical benefit, and asked for further phase 3 studies. We found no FDA-approved enclomiphene product as of October 2026.
• Compounding. FDA's list of bulk drug substances nominated for compounding under section 503A (updated May 14, 2026) places enclomiphene citrate in Category 1, "Bulk Drug Substances Under Evaluation." That's why compounded enclomiphene is being sold, including through telehealth. Compounded drugs are not FDA-approved products, and their quality depends on the pharmacy.

Side-by-side: TRT and the alternatives

Mechanisms per AUANews (2023). AUANews notes there is no FDA-approved therapy for male fertility.

If you're already on TRT

This is where people most often go wrong, in both directions. Some stop testosterone abruptly on their own and feel awful. Others keep going and assume their fertility will be fine. A better path:

1. Don't stop or switch on your own. Talk to the prescriber, and ideally a urologist with male-fertility experience, before changing anything.
2. Get a semen analysis. It tells you where you're starting from. Some men on TRT have very low counts. Some have none.
3. Ask about a transition plan. Specialists may use SERMs, hCG, or other approaches to restart the body's own production. The choice, sequence, and monitoring are individual. There's no standard regimen, and we're not giving doses here.
4. Allow time. Sperm production takes months to recover, and the AndroGel label warns that effects on fertility may be irreversible for some men. If you're planning a pregnancy, earlier is better.
5. Think about banking. If you're starting or continuing TRT and might want children later, ask whether freezing sperm first makes sense.

If you and your partner are already in fertility treatment, tell the clinic about any testosterone, steroids, or SERMs, past or present. It changes how they read a semen analysis and plan treatment.

What good care looks like

• A diagnosis first: repeated morning testosterone, LH and FSH, and an assessment of symptoms, before any treatment.
• A semen analysis before treatment if fertility matters to you now or later.
• Follow-up blood work, which may include estradiol, and repeat semen analyses on whatever treatment you start.
• A discussion of the side effects listed on the product label, including the gynecomastia reported in men on clomiphene, and clear instructions on when to call.
• Honesty about evidence and off-label status. A prescriber who explains what's approved, what isn't, and why is a good sign.

Lifestyle and supplement questions often come up at the same time. Our male fertility supplements guide sorts the evidence, and FertileStart's men's fertility basics covers the fundamentals.

Questions to ask your doctor

• Is my low testosterone primary (a testicular problem) or secondary (a signaling problem)? Does that change which options make sense?
• Given that I want children now or later, would you avoid testosterone therapy for me?
• If you suggest clomiphene or enclomiphene, why that one? Where would it come from, a standard pharmacy or a compounding pharmacy?
• Which labs and semen analyses will we check, and how often?
• What side effects should make me call you?
• If I'm already on TRT, what's the plan and timeline to protect or restore sperm production?

Frequently asked questions

Sources