TRT and fertility: what happens to sperm count

Testosterone replacement therapy (TRT) raises your testosterone level but can lower your sperm count, sometimes to zero. That isn’t a rare side effect: it follows from how the body controls both. If there is any chance you want children in the next few years, it is the first thing to raise with the clinician, before you choose a form or a plan.

Why testosterone lowers sperm production

Sperm production depends on two pituitary hormones. LH tells the testes to make testosterone, and FSH supports sperm production. When testosterone arrives from an injection, gel or capsule, the brain senses enough of it and turns both signals down.

The Depo-Testosterone label describes it directly: during treatment, endogenous testosterone release is inhibited through feedback on LH, and at large doses spermatogenesis may also be suppressed through feedback on FSH. Newer labels are blunter. The AndroGel 1.62% label warns that exogenous androgens “may lead to azoospermia”, and the Kyzatrex label says it “may cause azoospermia”. Azoospermia means no measurable sperm in the semen.

This applies to every form: injections, gels, creams and oral capsules all deliver testosterone, and all can trigger the same feedback. Compounded products work the same way.

What the trials show

The clearest comparison comes from two parallel phase III trials in overweight men aged 18 to 60 with secondary hypogonadism. Men took enclomiphene or testosterone gel (AndroGel 1.62%) for 16 weeks and gave semen samples at the start and end.

An earlier phase II trial found the same split in hormones: enclomiphene raised LH and FSH, while gel raised testosterone “with suppressed LH levels”.

The trials ran for months, not years, and the labels we checked don’t give a recovery time after stopping testosterone. If you have been on TRT and now want children, a urologist or fertility specialist can test your semen and hormones and discuss the next step.

What the guidelines say

The Endocrine Society recommends against starting testosterone in men who are planning fertility in the near term. The AUA guideline includes statements specifically for testosterone-deficient men who want to preserve fertility. Both put the decision before treatment, not after. The Endocrine Society also recommends confirming low testosterone with repeat fasting morning tests and then looking for its cause, which matters here: in secondary hypogonadism the testes can still respond to LH and FSH, which is what the fertility-sparing options below rely on.

Options that raise your own testosterone

For men with secondary hypogonadism, whose testes still respond to LH and FSH, clinicians have options that work through the pituitary instead of replacing testosterone.

Enclomiphene

Enclomiphene is a daily pill that blocks estrogen’s feedback at the brain, raising LH and FSH. It is the drug behind the trial results above. No enclomiphene product is FDA-approved: compounding pharmacies prepare it under the FDA’s interim policy for its 503A Category 1 list, which can change. It is not a controlled substance. Long-term safety in men hasn’t been established. Online, it costs $67 to $99.99 a month at the providers that publish a monthly price, as of October 2026:

PeterMD charges $278 for a 2-month plan, regularly $345. See enclomiphene prices and enclomiphene vs TRT.

Clomiphene

Clomiphene (Clomid) is FDA-approved for ovulation problems in women, and prescribing it to men is off-label. The Clomid label describes it as a mix of two isomers, zuclomiphene and enclomiphene. In a small study of 12 healthy men taking 50 mg a day for 30 days, testosterone rose 146% on average, LH 177% and FSH 170%. The label warns of visual symptoms such as blurring, spots or flashes, which may be irreversible with higher doses or longer use. Hone Health charges $38 a month plus its membership ($193 all in with the $155 Premium tier), and Rex MD includes Clomid in its $250 to $299 program, as of October 2026.

hCG

hCG acts like LH on the testes. The Novarel label approves it for selected cases of hypogonadotropic hypogonadism in males, with regimens such as 4,000 USP units three times a week for 6 to 9 months. Using it alongside testosterone to keep the testes working is off-label. The label also notes sporadic reports of testicular tumors in young men treated with hCG for infertility, without a proven link.

hCG became a biologic on March 23, 2020, and the FDA says biological products are no longer eligible for the compounding exemptions. In practice, that leaves FDA-approved Novarel, Pregnyl and generic chorionic gonadotropin. None of the providers we track names an approved hCG product, so we don’t list any hCG offers. If a clinic offers hCG, ask which product it is.

How online clinics describe fertility

Clinic pages make fertility claims of their own, and they don’t all match the labels. Maximus publishes a comparison of its four protocols that marks injectable testosterone as “Suppressed” for fertility markers, with a footnote that pairing it with hCG “can maintain testicular size and sperm production”. It marks its testosterone cream as “Maintained” when taken with enclomiphene, and its compounded oral testosterone and enclomiphene as “Maintained”. TRT Nation lists “Preserves Fertility” for enclomiphene, and Hims calls enclomiphene a “fertility-friendly option”.

The enclomiphene claims line up with the phase III results above, which ran for 16 weeks. The claim for oral testosterone is harder to square with the FDA labels: Kyzatrex, an approved oral testosterone, carries a warning that it may cause azoospermia. A compounded product hasn’t been through FDA review at all. If a clinic says a testosterone product maintains fertility, ask what study supports it, how long it ran, and whether it measured sperm counts or only hormone levels.

Every provider on our best online TRT clinics list is ranked by our published rating method, and the enclomiphene price list shows which ones prescribe it. Lab testing before prescribing matters here too: Hone Health, Hims and Maximus describe labs before enclomiphene, while Strut Health’s enclomiphene page doesn’t describe one.

Questions to ask before you start TRT

• Do I have primary or secondary hypogonadism, and does that change which treatments can work for me?
• If I might want children, should I start with enclomiphene or clomiphene instead?
• Should I have a semen analysis before starting?
• If I start testosterone and later want children, what is the plan?
• Is the product you prescribe FDA-approved or compounded?

The legal side

Testosterone is a Schedule III controlled substance, and online clinics prescribe it without an in-person exam under a DEA and HHS temporary rule (90 FR 61301) that runs through December 31, 2026. Enclomiphene, clomiphene and hCG aren’t federally controlled, so that rule doesn’t apply to them, though each still needs a prescription. See TRT telehealth rules.

The bottom line

Testosterone therapy can lower sperm production to zero, and the Endocrine Society advises against starting it if you plan to father a child soon. Enclomiphene kept sperm counts normal in 16-week trials and costs $79 to $197 a month online, and off-label clomiphene costs $193 a month at Hone Health, membership included, as of October 2026. Talk to a licensed clinician, or a urologist, before you start. Compare providers on our testosterone hub.