If you are researching testosterone therapy and want to understand what it means for fertility, you are asking the right question — and asking it before starting treatment, not after. Exogenous testosterone therapy has a well-documented, direct effect on sperm production. For men who want children now or in the future, that effect is not a footnote. It is the central clinical consideration.
This guide explains what the evidence shows about testosterone therapy and male fertility, what the current FDA label requires, and what a qualified clinician needs to address before any treatment decision is made. It does not recommend or rank any product and does not substitute for an evaluation by a urologist, endocrinologist, or reproductive specialist.
If you arrived here after reading our related article on pelvic floor function and sexual health, this guide picks up where that conversation leaves off — on the hormonal and reproductive considerations that sit behind any discussion of male sexual and reproductive health.
What Testosterone Therapy Is Approved to Treat
Prescription testosterone products in the United States are FDA-approved as hormone replacement therapy for men with low testosterone caused by specific medical conditions. These conditions include primary hypogonadism — where the testes themselves are not functioning properly — and secondary hypogonadism, where the pituitary gland is not producing enough signaling hormones to stimulate the testes. Verified causes include genetic conditions such as Klinefelter syndrome, damage from chemotherapy, and testicular injury or infection.
The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) confirms that when a man has both erectile dysfunction and confirmed low testosterone, a clinician may prescribe testosterone — often alongside phosphodiesterase type 5 (PDE5) inhibitors — delivered as an oral medicine, patch, or gel. Testosterone is one tool in that context; it is not an automatic option for age-related changes or performance concerns.
That distinction has regulatory weight. As of 2015, FDA labeling included a statement that safety and effectiveness of testosterone replacement therapy had not been established for men whose low testosterone is caused by age-related decline rather than a diagnosed medical condition. As of mid-2026, HHS has requested updated label language that would remove that restriction — but clinical experts continue to be clear: “Testosterone is still a medical therapy, not a wellness drug. Proper diagnosis is essential before starting therapy.” The label change proposal does not eliminate the need for a proper hormonal workup before prescribing.
Why Testosterone Therapy Suppresses Sperm Production
This is the mechanism every man of reproductive age needs to understand before considering exogenous testosterone therapy.
The body regulates testosterone and sperm production through the hypothalamic-pituitary-gonadal (HPG) axis. The hypothalamus releases gonadotropin-releasing hormone (GnRH), which signals the pituitary gland to release two key hormones: luteinizing hormone (LH) and follicle-stimulating hormone (FSH). LH stimulates Leydig cells in the testes to produce testosterone. FSH acts on Sertoli cells to support spermatogenesis — the production of sperm. The system runs on internal feedback loops and, under normal conditions, keeps testosterone and sperm production in balance.
When testosterone is administered from outside the body, the hypothalamus and pituitary detect elevated testosterone in the bloodstream and reduce their output of GnRH, LH, and FSH. With LH and FSH suppressed, the testes stop receiving the signal to make either testosterone internally or sperm. Sperm production stops or falls dramatically. This suppression is so reliable that testosterone has been formally investigated as a male contraceptive.
A 2013 review titled “Exogenous Testosterone: A Preventable Cause of Male Infertility” (Crosnoe et al., Translational Andrology and Urology, 2013;2:106-13) outlined these mechanisms and documented how many men started testosterone therapy without being counseled about this fertility risk. The 2025 review by Hochu, Geyer-Kim, and Kim in Translational Andrology and Urology (TAU 2025;14(12):3975-3987; DOI: 10.21037/tau-2025-480) confirmed it remains a defining clinical challenge.
What the Evidence Says About Recovery
Most men who stop testosterone therapy do recover sperm production, but the timing and completeness of that recovery are not guaranteed. The most rigorous data come from male contraceptive trial research. One analysis of hormonal contraceptive studies (Liu et al., Lancet 2006;367:1412-20; DOI: 10.1016/S0140-6736(06)68614-5) found that 67% of men recovered a sperm concentration of at least 20 million per milliliter within six months of stopping treatment. However, some men in that data required up to two years to reach that threshold.
Recovery to an individual man’s pre-treatment baseline is not universal, particularly for men who had poor semen parameters before starting therapy. Age, duration of therapy, and baseline sperm quality all influence how quickly or fully the HPG axis recovers. There is currently no reliable pre-treatment test that predicts how a specific man will respond after stopping.
The practical takeaway: recovery is likely for most men but is neither immediate nor certain. Men who have not yet completed their family should discuss sperm banking before beginning any testosterone therapy.
What the Current FDA Label Requires
Suppressed sperm production remains a listed side effect on every FDA-approved testosterone product label, and that has not changed under any recent label revision. The full current side-effect profile includes suppressed sperm production, increased red blood cell count, acne, breast tenderness, fluid retention, worsened sleep apnea, and increased blood pressure.
In 2025, the FDA removed the class-wide cardiovascular boxed warning from all testosterone products following the TRAVERSE trial, which demonstrated that testosterone therapy was not inferior to placebo for major adverse cardiovascular events. A blood pressure warning — based on ambulatory monitoring studies, particularly with oral formulations — was added in its place. This change was confirmed by the FDA in 2025 labeling updates (U.S. Food and Drug Administration, “FDA issues class-wide labeling changes for testosterone products,” 2025).
A separate point that matters practically: testosterone and anabolic-androgenic steroids are Schedule III controlled substances. Products marketed without a prescription as “testosterone boosters” or “sexual enhancement” supplements do not contain pharmaceutical testosterone — if they did, they would be adulterated drugs subject to FDA enforcement. The FDA has taken enforcement actions against numerous such products over the years for containing undisclosed pharmaceutical ingredients. This means the label risks that apply to prescription testosterone do not apply to OTC supplements, but it also means those supplements are not the same treatment and cannot be compared to it.
When a Man Wants to Preserve Fertility
The 2024 AUA/ASRM Male Infertility Guideline (Brannigan et al., Journal of Urology 2024;212:789-99; DOI: 10.1097/JU.0000000000004180) contains two strong, Grade A recommendations that are directly relevant here:
- The long-term impact of exogenous testosterone on spermatogenesis should be discussed with every patient interested in future fertility.
- Exogenous testosterone therapy should not be prescribed to men who are currently trying to conceive.
These are not soft suggestions. They are strong guideline recommendations backed by Grade A evidence. For men who want to preserve or maintain fertility while also managing diagnosed testosterone deficiency, the same guideline describes a set of alternative approaches — but characterizes the evidence supporting them as conditional, meaning the benefit is likely but the evidence base is more limited.
Human Chorionic Gonadotropin (hCG)
hCG acts like LH in the body, directly stimulating Leydig cells to produce testosterone without suppressing the HPG axis from above. A 2013 study (Hsieh et al., Journal of Urology 2013;189:647-50; DOI: 10.1016/j.juro.2012.09.043) followed 26 hypogonadal men who desired fertility preservation and who received testosterone (intramuscular or gel) plus 500 IU of hCG every other day for up to 18 months. Testosterone levels rose from a mean of 207 to 1,055 ng/dL, and semen parameters showed no statistically significant decline. A separate study (Coviello et al., Journal of Clinical Endocrinology and Metabolism 2005;90:2595-602; DOI: 10.1210/jc.2004-0802) found that 250 IU of hCG every other day was sufficient to limit intratesticular testosterone suppression to only 7% despite full gonadotropin suppression from exogenous testosterone.
Important limits: hCG is FDA-approved for treatment of hypogonadotropic hypogonadism, but the evidence supporting its use specifically for spermatogenesis preservation alongside TRT is rated as conditional by the AUA — meaning the full picture is still developing. The AUA infertility guidelines note that current evidence is insufficient to fully support the concurrent-hCG approach and that spermatogenesis is not reliably maintained long-term with hCG alone without FSH support.
Selective Estrogen Receptor Modulators (SERMs)
SERMs such as clomiphene citrate work at the hypothalamus by blocking estrogen receptors, which causes the hypothalamus to increase GnRH release and the pituitary to release more LH and FSH. This raises endogenous testosterone without introducing external testosterone and without suppressing the HPG axis. SERMs are used off-label for testosterone deficiency with fertility preservation intent. Reported benefits include improved libido, energy, and mood. Potential side effects include gynecomastia, weight gain, elevated blood pressure, acne, and rare visual disturbances.
Enclomiphene Citrate
Enclomiphene citrate is the purified trans-isomer of clomiphene. It offers more selective HPG axis stimulation than the racemic mixture and fewer estrogenic side effects. Phase III clinical trial data (Kim, McCullough, Kaminetsky, BJU International 2016;117:677-85; DOI: 10.1111/bju.13337) involving 256 overweight hypogonadal men found that enclomiphene raised testosterone, LH, and FSH while preserving sperm concentration in the normal range — compared to testosterone gel, which raised testosterone but markedly suppressed sperm counts. The composite endpoint (testosterone in normal range plus sperm concentration ≥10 million/mL) was achieved in 63.5% of men on enclomiphene versus 24.7% on testosterone gel.
Critical limit: enclomiphene is not FDA-approved. The manufacturer received a Complete Response Letter from the FDA in 2015, indicating the submitted data were insufficient; development for all medical indications was discontinued in 2021. Enclomiphene remains available through compounding pharmacies with a prescription. Anyone considering it should understand its off-label and compounded status.
Aromatase Inhibitors (AIs)
AIs block the conversion of testosterone to estradiol. In men with a low testosterone-to-estradiol ratio, this can raise LH, FSH, and endogenous testosterone. The 2024 AUA/ASRM Male Infertility Guideline endorses AI use in select men with testosterone deficiency and elevated estradiol. AIs are off-label for this use. Side effects can include elevated blood pressure, musculoskeletal discomfort, and — with long-term use — reduced bone mineral density. Doses should be carefully titrated; persistently elevated estradiol despite therapy warrants discontinuation.
Three Categories That Look Similar but Are Not
The commercial landscape around testosterone is crowded and often misleading. Here is a plain-English framework for understanding what you are looking at when you encounter testosterone-adjacent language.
- Diagnosed hypogonadism treated with FDA-approved therapy: Confirmed, pathological low testosterone documented by two separate morning blood draws plus LH and FSH measurements, in a man with symptoms meeting clinical criteria, receiving a prescription formulation prescribed by a licensed clinician who has reviewed his full medical history and fertility goals. This is monitored, regulated medicine.
- Age-related testosterone decline: Testosterone levels tend to decline gradually over time in many men, though recent research suggests metabolic health and comorbidities may be larger drivers than chronological age alone. This is not automatically hypogonadism. FDA-approved testosterone therapy has historically not been approved specifically for this population, though proposed 2026 label changes may shift how some prescribers approach borderline cases. Guideline guidance continues to require proper diagnostic workup regardless of label language changes.
- Enhancement marketing: Supplements and tonics marketed for energy, libido, or athletic performance are not testosterone. They typically contain botanical extracts or amino acids positioned near testosterone-adjacent language. They are regulated as dietary supplements, not drugs. They cannot legally claim to treat, cure, diagnose, or prevent a medical condition. When label copy implies otherwise, that is a regulatory compliance issue, not a clinical recommendation.
Starting with a licensed clinician who orders appropriate bloodwork is the only way to know which of these three categories actually applies to your situation.
Evidence Worksheet: Claims, Sources, and Limits
The following maps the most commonly encountered claims to what the evidence actually supports, what is unresolved, and what to do next.
- Claim: Testosterone therapy suppresses sperm production.
Source type: Well-established clinical pharmacology; AUA guidelines, multiple peer-reviewed studies, current FDA product labeling, and the 2025 TAU review (Hochu, Geyer-Kim, Kim; DOI: 10.21037/tau-2025-480).
What it establishes: Exogenous testosterone suppresses LH and FSH via HPG axis negative feedback, reducing both internal testosterone production and spermatogenesis. This is confirmed, reproducible mechanism — not a rare adverse event.
Unresolved: Individual rate and completeness of post-treatment recovery varies; no reliable pre-treatment predictor exists for a given man.
Next step: Any man of reproductive age considering testosterone therapy should discuss sperm banking before initiation and obtain a baseline semen analysis. - Claim: Most men recover sperm production after stopping testosterone therapy.
Source type: Analysis of male hormonal contraceptive trials (Liu et al., Lancet 2006;367:1412-20; DOI: 10.1016/S0140-6736(06)68614-5).
What it establishes: 67% of men recovered a sperm concentration of at least 20 million/mL within 6 months of stopping treatment; some men required up to 2 years. Recovery is not universal, particularly for men with poor baseline semen quality.
Unresolved: The data come from contraceptive trial populations, which may not fully represent men on long-term TRT for hypogonadism. Recovery timelines for individual patients remain unpredictable.
Next step: Do not rely on expected recovery as a substitute for pre-treatment sperm banking if fertility is a priority. - Claim: hCG can preserve fertility while testosterone therapy continues.
Source type: Clinical studies reviewed in Hochu et al. TAU 2025 (see above); conditional recommendation in AUA/ASRM Male Infertility Guideline (Brannigan et al., J Urol 2024;212:789-99; DOI: 10.1097/JU.0000000000004180).
What it establishes: Multiple studies show hCG can sustain intratesticular testosterone and maintain semen parameters in men on concurrent TRT. hCG is FDA-approved for hypogonadotropic hypogonadism.
Unresolved: Evidence is rated conditional by the AUA. Spermatogenesis is not reliably maintained long-term with hCG alone without FSH support. Optimal dosing protocols and long-term outcomes need further study.
Next step: Ask a reproductive urologist or reproductive endocrinologist whether an hCG co-prescription is appropriate given your specific diagnosis and fertility goals — not all presentations qualify. - Claim: OTC testosterone boosters work the same way as prescription testosterone therapy.
Source type: FDA regulatory classification; Schedule III controlled substance status of testosterone; FDA enforcement history against adulterated supplements.
What it establishes: OTC supplements are not the same as FDA-approved testosterone therapy and do not contain pharmaceutical testosterone. No OTC supplement is approved to treat hypogonadism. Ingredient-specific supplements (e.g., ashwagandha, D-aspartic acid) have limited and inconsistent human trial data on testosterone levels.
Unresolved: Ingredient-level research for some botanical compounds continues; no OTC compound has established clinical equivalence to pharmaceutical TRT.
Next step: Verify any ingredient claim against PubMed-indexed human trial data. Discuss all supplement use with your prescriber before combining with any prescription hormone therapy.
Questions to Bring to a Qualified Clinician
This article cannot determine whether testosterone therapy is appropriate for you. That requires a physical examination, complete medical history, morning blood draws on at least two separate occasions, and LH and FSH measurements to characterize the type and cause of any testosterone deficiency. What this guide can do is help you walk into that appointment with the right questions.
- What is my diagnosis — primary hypogonadism, secondary hypogonadism, age-related decline, or something else? What did my LH and FSH levels show?
- I want to preserve my fertility. Does that change which treatment is appropriate for me?
- Should I bank sperm before starting any treatment?
- If testosterone therapy is indicated, which formulation and delivery method best fits my situation?
- What monitoring will I need, and how often?
- Are any supplements or OTC products I am currently taking likely to interact with treatment?
These questions are not about challenging your clinician. They are about ensuring that your fertility goals and your treatment goals are both on the table from the beginning — because the two require different conversations and sometimes different approaches.
The Bottom Line
Testosterone therapy has a legitimate, evidence-based role in treating diagnosed hypogonadism. Its effects on male fertility are equally well-documented, present on every FDA-approved product label, and clinically significant for any man who wants to have children now or in the future.
The decision boundary is clear: the 2024 AUA guideline states that exogenous testosterone should not be prescribed to men currently trying to conceive, and that every patient interested in future fertility should be counseled about the long-term impact on spermatogenesis before treatment begins. Men who want to preserve fertility while managing testosterone deficiency have evidence-supported alternatives — but those alternatives require a clinician who is managing both goals at once, with appropriate laboratory monitoring.
Enhancement marketing in the supplement or wellness space operates in a different regulatory category entirely. It should not be mistaken for evidence-based clinical guidance, and the absence of a cardiovascular boxed warning on TRT products since 2025 does not change the fertility risk picture.
Read the evidence here, prepare the questions above, and bring them to a urologist, endocrinologist, or reproductive specialist before any treatment decision is made.
This article is produced for educational purposes by the DrBayer.com Editorial Team. It does not constitute medical advice, diagnosis, or treatment. Always consult a qualified health care professional before making decisions about hormone therapy or reproductive health.