Evidence question

PubMed sourcedAbstract-based analysisUpdated Sep 2026Human reviewedUpdated Aug 2026

Evidence / Men's Hormone Health

CoverageMen's Hormone Health

Does testosterone therapy suppress fertility in men?

Reviewed by Neal Rouzier, MD, Preventive Medicine · Aug 2026

Updated Aug 2026·14 studies analyzed·2 core studies·Applies to: hypogonadal men

Bottom line

Exogenous testosterone suppresses the hypothalamic-pituitary-gonadal axis and reliably reduces spermatogenesis. Recovery after discontinuation is variable and may be incomplete in some men.[1–6]

Evidence confidence

Evidence Confidence

High
LimitedModerateHigh

Multiple high-quality studies directly address this question, with generally consistent findings.

Key uncertainty. Recovery timelines and completeness of spermatogenesis after TRT discontinuation vary by age, treatment duration, and baseline sperm parameters.

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Also asked

Can you be fertile while on TRT?▼

Exogenous testosterone suppresses the hypothalamic-pituitary-gonadal axis and reliably reduces spermatogenesis. Fertility during TRT is uncommon without concurrent gonadotropin-based protocols.

Does testosterone suppress fertility?▼

Yes — testosterone is used as a male contraceptive mechanism because it suppresses sperm production. Recovery after discontinuation is variable and may be incomplete.

TRT and sperm count▼

TRT lowers sperm count through pituitary suppression of FSH and LH. Men who desire near-term fertility should consider alternatives such as clomiphene or hCG before starting exogenous testosterone.

testosterone affect fertility spermatogenesis men▼

Testosterone impairs spermatogenesis by suppressing intratesticular testosterone signaling. Discuss sperm banking before initiation when future fertility is possible.

Testosterone infertility▼

Exogenous testosterone suppresses the hypothalamic-pituitary-gonadal axis and reliably reduces spermatogenesis. Recovery after discontinuation is variable and may be incomplete in some men.

Will testosterone therapy affect ability to have children?▼

Exogenous testosterone suppresses the hypothalamic-pituitary-gonadal axis and reliably reduces spermatogenesis. Recovery after discontinuation is variable and may be incomplete in some men.

Body of evidence

Clinical Evidence Brief

RAGMD analyzed 13 relevant studies.

Overall finding

6 studies address fertility / spermatogenesis, with weighted findings showing mixed findings. 2 studies address sleep-related cognitive symptoms, with weighted findings showing a positive association. 3 studies address bone mineral density, with weighted findings showing no meaningful effect. 1 study addresses weight / body composition, with weighted findings showing unclear findings. 5 randomized or systematic-review reports and 8 observational studies address treatment. Men who desire near-term fertility should not start exogenous testosterone without specialist evaluation.

Evidence by outcome

Direction: ↑ Favors treatment / reassuring · ↓ Harm signal · ↔ No clear effect · ± Mixed · ↗ Observational link · ? Unclear

Mixed

Fertility / spermatogenesis

high · 6 studies

6 studies address fertility / spermatogenesis, with weighted findings showing mixed findings. This is an objectively measured outcome. This is a hard clinical endpoint.

Objectively measured · Hard clinical endpoint

Studies

PMID 39820213PMID 27855957PMID 34999717PMID 31988219PMID 31495240PMID 25873947
Positive link

Sleep-related cognitive symptoms

high · 2 studies

2 studies address sleep-related cognitive symptoms, with weighted findings showing a positive association.

Mixed measurement

Studies

PMID 34536053PMID 35904664
Reassuring

Bone mineral density

moderate · 3 studies

3 studies address bone mineral density, with weighted findings showing no meaningful effect. This is an objectively measured outcome. This is a surrogate endpoint and does not by itself prove a hard clinical outcome.

Objectively measured · Surrogate endpoint

Studies

PMID 19820017PMID 26901812PMID 11730247
Unclear

Weight / body composition

moderate · 1 study

1 study addresses weight / body composition, with weighted findings showing unclear findings. This is an objectively measured outcome. This is a surrogate endpoint and does not by itself prove a hard clinical outcome.

Objectively measured · Surrogate endpoint

Studies

PMID 35904664
Unclear

Quality of life

moderate · 1 study

1 study addresses quality of life, with weighted findings showing unclear findings. This is a patient-reported / subjective outcome.

Patient-reported

Studies

PMID 35904664
Reassuring

Fractures

moderate · 1 study

1 study addresses fractures, with weighted findings showing no meaningful effect. This is an objectively measured outcome. This is a hard clinical endpoint.

Objectively measured · Hard clinical endpoint

Studies

PMID 19820017

Magnitude / clinical importance

Validated effect estimates in the analyzed set include or 10. Statistical significance is not the same as clinical importance.

Interpret magnitude in absolute terms for the patient in front of you, not from relative estimates alone.

Agreement across studies

Most studies agree on quality of life (unclear findings), while fertility / spermatogenesis findings are mixed findings and more consistent across domains.

Supports main conclusion: 1 · Neutral / mixed: 12 · Credible conflicting: 0

Study counts describe the landscape; RAGMD weights studies according to design, quality, and directness.

Conflicting findings

  • To determine factors that influence sperm recovery after T-associated infertility.
  • Testosterone therapy should be individualized with cardiovascular risk assessment and monitoring rather than categorically avoided.
  • The results indicated that OSA is significantly correlated with the decrease in serum testosterone levels in men.
  • Estrogens primarily regulate bone homeostasis in adult men, and testosterone and estradiol levels must decline substantially to impact the skeleton.

Risks & harms

3 studies report safety-relevant findings. Design mix: Study design not clearly classified, Narrative review. Rare-event inference should not rest on underpowered trials alone.

Who this applies to

Most studies included hypogonadal men.

What remains uncertain

  • Recovery timelines and completeness of spermatogenesis after TRT discontinuation vary by age, treatment duration, and baseline sperm parameters.
  • Recovery timelines and completeness of spermatogenesis after TRT discontinuation vary by age, treatment duration, and baseline sperm parameters.
  • Surrogate improvement does not prove a hard clinical outcome.

Clinical takeaway

Men who desire near-term fertility should not start exogenous testosterone without specialist evaluation. Alternatives such as clomiphene, human chorionic gonadotropin, or gonadotropin-based regimens may preserve spermatogenesis while treating hypogonadal symptoms. If TRT is required, discuss sperm banking before initiation.

Mixed

Fertility / spermatogenesis?

Mixed findings

high[39820213 · 27855957 · 34999717 · 31988219 · 31495240 · 25873947]

Positive link

Sleep-related cognitive symptoms?

A positive association

high[34536053 · 35904664]

Reassuring

Bone mineral density?

No meaningful effect

moderate[19820017 · 26901812 · 11730247]

Unclear

Weight / body composition?

Unclear findings

moderate[35904664]

Unclear

Quality of life?

Unclear findings

moderate[35904664]

Reassuring

Fractures?

No meaningful effect

moderate[19820017]

Reassuring

Venous thromboembolism?

No meaningful effect

limited[26205547]

Unclear

Hematocrit / erythrocytosis?

Unclear findings

limited[35467476]

5 randomized or systematic-review reports and 8 observational studies address treatment. Weighted treatment findings show mixed findings.

5 RCT / systematic review · 8 observational

Large randomized trials strongly influence the conclusion

2 landmark studies with randomized or systematic-review designs strongly inform this conclusion.

Supporting studies provide additional context

12 supporting studies add context beyond the core evidence base.

Regimen & duration

Observational and supporting studies provide context and do not outrank higher-appropriateness designs.

Long-term uncertainty

Evidence beyond long follow-up windows and in certain subgroups remains less complete.

14 analyzed studies

Strongest evidence

Asian journal of andrology2025

Landmark studyPMID 39820213

Clinician's guide to the management of azoospermia induced by exogenous testosterone or anabolic-androgenic steroids.

Azoospermia, defined as the absence of sperm in the ejaculate, is a well-documented consequence of exogenous testosterone (ET) and anabolic-androgenic steroid (AAS) use. These agents suppress the hypothalamic-pituitary-gonadal (HPG) axis, leading to reduced intratesticular testosterone levels and impaired spermatogenesis.

Review
Evidence
Relevance

Supporting literature

Association between obstructive sleep apnea and male serum testosterone: A systematic review and meta-analysis.

Obstructive sleep apnea and serum total testosterone: a system review and meta-analysis.

Effects of aromatase inhibition on bone mineral density and bone turnover in older men with low testosterone levels.

+9 more

More in this focus area

Related evidence analyses

Other structured clinical questions in Men's Hormone Health.

Does testosterone replacement increase cardiovascular risk?

Large randomized data (including TRAVERSE) do not show a significant increase in major adverse cardiovascular events with testosterone therapy in hypogonadal men over median follow-up of roughly three years. Older observational studies conflict, and absolute risk depends on baseline cardiovascular disease, formulation, and monitoring.

11 linked studies

Does testosterone therapy increase prostate cancer risk?

Current systematic reviews and trial secondary analyses do not show a convincing increase in prostate cancer incidence among hypogonadal men treated with testosterone, though surveillance remains standard practice.

14 linked studies

Does testosterone therapy increase hematocrit and polycythemia risk?

Testosterone therapy commonly raises hematocrit; polycythemia is a recognized adverse effect requiring dose adjustment, formulation changes, or phlebotomy when thresholds are exceeded.

14 linked studies

Does testosterone therapy increase venous thromboembolism risk?

Large observational cohorts suggest a modest increase in venous thromboembolism risk with testosterone therapy, particularly early after initiation. Absolute risk remains low in most populations but warrants attention in predisposed patients.

14 linked studies

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