TRT and Fertility: a GP referrer’s guide
Testosterone replacement therapy (TRT) can improve symptoms in appropriately selected men with confirmed testosterone deficiency. However, exogenous testosterone can significantly suppress sperm production and may cause severe oligospermia or azoospermia.[1–4]
For men who want children now—or may want children in the future—fertility should be discussed before TRT is commenced.
Why does TRT affect fertility?
Testosterone taken from outside the body suppresses signalling from the hypothalamus and pituitary, reducing luteinising hormone (LH) and follicle-stimulating hormone (FSH). This lowers testosterone levels inside the testes, where high concentrations are required for normal sperm production.[1–4]
Current AUA/ASRM and EAU guidelines recommend against exogenous testosterone in men actively pursuing fertility.[1,2] TRT should also not be considered contraception because sperm suppression is variable.
Before starting TRT: what should the GP check?
First, ask directly: “Do you want children now or in the future?” If the answer is yes or uncertain, this may change management.
Confirm genuine testosterone deficiency using symptoms or signs together with repeat morning testosterone measurements. LH should help distinguish primary from secondary hypogonadism; FSH is particularly useful when fertility is relevant. Prolactin may be indicated when secondary hypogonadism is suspected.[3,4]
Where future fertility matters, consider a baseline semen analysis. This may identify pre-existing impaired sperm production before testosterone is started. Patients who already have results can also use the Semen Analysis Interpreter.
Review potentially reversible contributors including obesity, sleep disorders, opioids and other medications, systemic illness, pituitary disease, and previous anabolic-androgenic steroid use.
What if a patient on TRT now wants a pregnancy?
Do not assume sperm production will return immediately after TRT is withdrawn.
In male hormonal-contraception studies, approximately two-thirds of men recovered to a sperm concentration of 20 million/mL by six months and around 90% by 12 months.[5] However, these data do not precisely predict recovery after prolonged clinical TRT. Older age, longer testosterone exposure and underlying testicular dysfunction may delay recovery.[6,7]
A useful initial GP assessment includes semen analysis, morning testosterone, LH and FSH, with prolactin when indicated. Document the type and duration of TRT or anabolic steroid exposure and any history of undescended testes, testicular surgery, chemotherapy, radiotherapy or previous infertility.
Consider earlier specialist referral when there is azoospermia, severe oligospermia, testicular atrophy, prolonged TRT/anabolic steroid exposure, significant previous testicular disease, or time pressure because of the female partner’s age or fertility treatment.
What happens after referral?
Management depends on the underlying cause of low testosterone, semen findings and the couple’s timeframe for pregnancy.
In selected men, specialist-directed approaches that stimulate the body’s own reproductive hormone pathway may be considered rather than exogenous testosterone.[1–3,6,7] Treatment needs to be individualised, particularly because evidence for some fertility-preserving hormonal strategies remains limited.
For patient information, see Fertility After Testosterone or the Male Infertility & Reproductive Urology service.
GP take-home message
Ask about fertility before prescribing TRT. If fertility is desired, obtain an appropriate reproductive assessment and avoid assuming exogenous testosterone is fertility-neutral. Early referral can be particularly useful when sperm production is severely suppressed or the couple cannot afford a prolonged period of observation.
Specialist assessment is available for Brisbane, interstate and international patients. Where clinically appropriate, interstate or overseas assessment can begin with review of existing investigations before travel. See International Patient Information or Request an Appointment.
References
Brannigan RE, Hermanson L, Kaczmarek J, Kim SK, Kirkby E, Tanrikut C. Updates to male infertility: AUA/ASRM guideline (2024). J Urol. 2024;212(6):789-799. doi:10.1097/JU.0000000000004180.
European Association of Urology. EAU Guidelines on Sexual and Reproductive Health: Male Infertility and Male Hypogonadism. EAU Guidelines Office; current online edition. Accessed August 2026.
Mulhall JP, Trost LW, Brannigan RE, et al. Evaluation and management of testosterone deficiency: AUA guideline. J Urol. 2018;200(2):423-432.
Bhasin S, Brito JP, Cunningham GR, et al. Testosterone therapy in men with hypogonadism: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2018;103(5):1715-1744.
Liu PY, Swerdloff RS, Christenson PD, Handelsman DJ, Wang C. Rate, extent, and modifiers of spermatogenic recovery after hormonal male contraception: an integrated analysis. Lancet. 2006;367(9520):1412-1420.
McBride JA, Coward RM. Recovery of spermatogenesis following testosterone replacement therapy or anabolic-androgenic steroid use. Asian J Androl. 2016;18(3):373-380.
Kohn TP, Louis MR, Pickett SM, et al. Age and duration of testosterone therapy predict time to return of sperm count after human chorionic gonadotropin therapy. Fertil Steril. 2017;107(2):351-357.e1.
Medical disclaimer: This article provides general educational information for health professionals and patients and does not replace individual medical assessment or prescribing advice. Management of testosterone deficiency and fertility should be individualised. Patients taking prescribed testosterone should not stop or alter treatment without discussing this with their treating clinician.
