Short answer: Testosterone therapy shuts down the brain signals (LH and FSH) that drive sperm production, so it can lower sperm counts, sometimes to zero. The Endocrine Society guideline recommends against starting testosterone in men planning fertility in the near term and suggests sperm banking for men unsure about future children. hCG mimics LH and is sometimes added to keep the testes working. The best-known study (26 men, retrospective) found no one became azoospermic on TRT plus low-dose hCG. That is helpful but small, uncontrolled evidence, and hCG is not FDA-labeled for this use.
"Will TRT make me infertile?" is one of the most searched TRT questions, and "TRT plus hCG" is the most common answer online. This article explains why testosterone affects fertility, what the main guideline says, what the evidence on hCG actually shows, and what recovery looks like after stopping. It is not dosing advice, and anyone trying to conceive should be seeing a clinician who treats male fertility.
Sperm production depends on two pituitary hormones, LH and FSH, and on very high testosterone levels inside the testes. When you take testosterone from outside, the body senses it and turns those signals down. The Depo-Testosterone label explains: "endogenous testosterone release is inhibited through feedback inhibition of pituitary luteinizing hormone (LH). At large doses of exogenous androgens, spermatogenesis may also be suppressed." It lists oligospermia (low sperm count) as a possible effect.
How often does it happen? One study of hCG co-treatment summarized the problem this way: testosterone therapy lowers gonadotropins and testicular testosterone and impairs sperm production, "leading to azoospermia in 40% of patients" (Hsieh 2013, citing earlier work). Responses vary a lot between men.
The American Urological Association's 2018 testosterone guideline (reviewed and confirmed in 2024) also includes statements for men interested in preserving fertility. Its full text is available to AUA members; we have not quoted it here because we could not open it.
Human chorionic gonadotropin (hCG) acts like LH: it tells the testes to keep making testosterone, which keeps testicular testosterone high even when the pituitary has gone quiet. It does not replace FSH.
hCG is FDA-approved, but not for this. The Novarel label lists two male uses: prepubertal cryptorchidism (undescended testes) and "selected cases of hypogonadotropic hypogonadism (hypogonadism secondary to a pituitary deficiency) in males." Using it alongside TRT to protect fertility is off-label.
The study most often cited is a retrospective chart review of 26 men on testosterone therapy with low-dose hCG (Hsieh 2013):
Hormone levels in the same study rose sharply: mean testosterone went from 207.2 ng/dL before treatment to 1,055.5 ng/dL during treatment, and free testosterone from 8.1 to 20.4 pg/mL. Those on-treatment levels are high, which is worth noting because the study was not designed to find the lowest effective approach.
The authors concluded low-dose hCG "appears to maintain semen parameters." Note the limits: 26 men, no control group, retrospective, from one practice. It is the best-known data point, not a definitive trial.
Other approaches exist. Selective estrogen receptor modulators such as clomiphene and enclomiphene raise LH and FSH instead of replacing testosterone. A 2025 meta-analysis of randomized trials found they raised total testosterone, LH and FSH compared with placebo, and raised LH and FSH compared with testosterone gel (Hohl 2025). See enclomiphene vs clomiphene and our comparison of hCG vs enclomiphene.
The best numbers come from male hormonal contraception studies, where healthy men took testosterone (sometimes with a progestin) on purpose to stop sperm production. An integrated analysis of 1,549 men across 30 studies found that sperm concentration recovered to 20 million/mL (a fertility marker) in a median of 3.4 months. The probability of recovery was 67% within 6 months, 90% within 12 months, 96% within 16 months and 100% within 24 months (Liu 2006). In the multivariate analysis, recovery was faster with older age, Asian origin, shorter treatment, shorter-acting testosterone preparations, higher sperm counts at baseline, faster suppression, and lower baseline LH. The authors note these factors changed the speed of recovery more than whether it happened.
Two cautions. These were men with normal baseline testosterone who stopped on a planned schedule. Men with true hypogonadism may not have normal sperm production to return to. And "within 24 months" is a long time for a couple trying to conceive.
The WADA 2026 Prohibited List bans chorionic gonadotrophin in males under S2.2.1, testosterone-stimulating peptides.
Dose Track lets you schedule testosterone and hCG separately, log each shot, track the hCG vial from reconstitution, and add semen analysis and hormone results to the same timeline.
Questions about the app? See the help center or join the Dose Track community.
Every number in this article comes from one of these sources, checked on October 22, 2026. This article is for education. It is not medical or legal advice, and nothing here is a dose recommendation.