Written by: Centre for Men's Health
Reviewed for medical accuracy by Dr Ed Rainbow, BMBS, MRCGP, MSc, men’s health expert
Last updated 26 January 2026
Testosterone replacement therapy may have many benefits for men, but it is also important to be aware of the side effects. In particular, TRT affects fertility, of concern particularly to younger patients still looking to have kids.
What effect does TRT have on sperm production?
Treatment with exogenous testosterone (testosterone not produced in the body) in the form of TRT leads to negative feedback via androgen receptors in the hypothalamus and the pituitary gland, reducing the release of GnRH (gonadotropin-releasing hormone), FSH (follicle-stimulating hormone) and LH (luteinising hormone).
This process can suppress FSH to below the levels required for spermatogenesis – the development of sperm from male germ cells – by Sertoli cells in the testes.
Exogenous testosterone also reduces release of LH, which in turn suppresses the production of the body’s own testosterone by the Leydig cells, also in the testes. Lower levels of testosterone inside the testes lead to reduced survival and development of germ cells required for sperm production.
Hormonal regulation of spermatogenesis
Image credit: inviTRA6
Will I recover my fertility if I stop TRT?
If you stop TRT, you are very likely to recover fertility, but it may take time. Studies show that around seven in 10 men (65-70%) will recover sperm densities to normal levels (≥15 million/mL) within 12 months of stopping TRT8. Most men recover within six to 12 months, though some may take up to two years1. Using structured protocols with hCG and medications like clomiphene can improve recovery rates to over 90% in some cases8,11.
However, older patients or those on long term treatment with TRT are less likely to see fertility return.
What treatments can help preserve fertility?
There are two main treatments that aim to boost the body’s own production of testosterone: Clomiphene citrate (Clomid), taken orally as tablets, and hCG (human chorionic gonadotropin), administered by injection.
How does Clomiphene citrate work?
By blocking oestrogen’s negative feedback at the pituitary, clomiphene keeps your own LH and FSH production active10. This is crucial because FSH directly stimulates the Sertoli cells that nurture developing sperm, while LH maintains intratesticular testosterone—the testosterone inside your testes—at levels 50-100 times higher than in your blood 9. This high local testosterone is essential for spermatogenesis. Because clomiphene works by boosting your body’s own hormone production rather than suppressing it, fertility is maintained.10
How does hCG work?
When you take TRT, your pituitary gland stops producing LH because the testosterone in your blood signals that you have “enough.” However, the testes need local (intratesticular) testosterone at very high concentrations for sperm production—far higher than blood levels 9. hCG mimics LH and directly stimulates the Leydig cells in your testes to produce testosterone locally, maintaining the intratesticular testosterone needed for spermatogenesis even when your own LH is suppressed by TRT7,2,9. Studies show that low-dose hCG (125-500 IU every other day) can maintain intratesticular testosterone within or above normal range in men on TRT, helping preserve sperm production 9.
Both these treatments support fertility as well as testosterone levels in men, but may have side effects and should be considered in detail with your doctor. At the Centre for Men’s Health, our doctors are happy to discuss the benefits and possible drawbacks of hCG and Clomid as forms of testosterone boosting treatment.
What if I’m already on TRT and want to restore fertility?
If you’re currently on TRT and want to restart sperm production, structured medical protocols can help restore fertility in most men. These approaches typically involve high-dose hCG, often combined with clomiphene, to re-establish your body’s natural hormone production. Doses are gradually reduced as testicular function improves.
Most men see sperm return within six to 12 months using these approaches, with recovery rates exceeding 90% in some studies8,11,12. Success depends on how long you’ve been on TRT, your age, and your baseline fertility.
These protocols require close monitoring and are individualised. At the Centre for Men’s Health, we can guide you through the process and work with fertility specialists when needed.
How can a clinic help if I want to have kids while on TRT?
For men who are planning to have kids or even considering the possibility in the near future, we strongly recommend sperm banking before starting TRT. At the Centre for Men’s Health we can refer patients to partner clinics who can arrange this.
Can you use TRT for contraception?
Short answer: Potentially, but it is not recommended.
While TRT does suppress sperm production in most men, it is not a reliable form of contraception and should not be used this way.
Why TRT isn’t suitable as contraception:
It’s not 100% effective. Although 70-90% of men on TRT develop severely reduced sperm counts (oligozoospermia) or no sperm (azoospermia), around 10-30% maintain enough sperm production to achieve pregnancy1. You cannot predict which group you’ll be in without repeated semen analysis.
It’s unpredictable. The degree of suppression varies between individuals and can change over time. Some men become azoospermic quickly; others maintain low but viable sperm counts for years1.
It’s not licensed for contraception. TRT is not approved or tested as a contraceptive method in the UK. Using it this way would be off-label use without safety data or regulatory oversight.
Recovery time varies widely. If you relied on TRT as contraception and then wanted children, recovery could take 6-24 months—an unpredictable waiting period 8.
Better options exist. Established contraceptive methods (condoms, vasectomy, partner contraception) are far more reliable and have known failure rates.
Bottom line: If you need contraception, use established methods. If you’re on TRT and don’t want children, don’t assume you’re infertile—use proper contraception or confirm azoospermia with semen analysis1.
TRT and fertility: conclusions
TRT can affect men’s fertility, which is potentially reversible. For men who want to have kids while on TRT, there are treatments that can preserve fertility but this needs to be discussed with your doctor.
References
1. Testosterone Is a Contraceptive and Should Not Be Used in Men Who Desire Fertility
World Journal of Mens Health, 2018 Oct 10
https://pmc.ncbi.nlm.nih.gov/articles/PMC6305868
2. Poster Session: Male Reproductive Urology. Low dose human chorionic gonadotropin prevents azoospermia and maintains fertility in hypogonadal men on testosterone replacement therapy
Fertility and Sterility, September 2010
https://www.fertstert.org/article/S0015-0282(10)01624-9/fulltext
3. Successful fertility treatment with gonadotrophin therapy for male hypogonadotrophic hypogonadism
J Rajkanna, S Tariq, S O Oyibo
Endocrinology, Diabetes & Metabolism Case Reports, 2016
https://pubmed.ncbi.nlm.nih.gov/26807263
4. Human Chorionic Gonadotropin monotherapy for the treatment of hypogonadal symptoms in men with total testosterone > 300 ng/dL
V Madhusoodanan, P Patel, T Fernandes Negris Lima, J Gondokusumo, E Lo, N Thirumavalavan, L I Lipshultz, R Ramasamy
International Brazilian Journal of Urology, 2019 Sep-Oct
https://pubmed.ncbi.nlm.nih.gov/31408289
5. The treatment of hypogonadism in men of reproductive age
E D Kim, L Crosnoe, N Bar-Chama, M Khera, L I Lipshultz
Fertility and Sterility, 2013 Mar
https://pubmed.ncbi.nlm.nih.gov/23219010
6. Hormonal regulation of spermatogenesis (diagram source)
inviTRA
https://www.invitra.com/en/spermatogenesis/regulation-hormonal-spermatogenesis/
7. Management of fertility in hypogonadal patients on testosterone replacement therapy
2024
https://pmc.ncbi.nlm.nih.gov/articles/PMC10890669
8. Azoospermia induced by testosterone replacement therapy: Clinical review and management strategies
2025
https://pmc.ncbi.nlm.nih.gov/articles/PMC12112917
9. Maintenance of intratesticular testosterone in normal men with testosterone gel and human chorionic gonadotropin
Coviello AD, et al.
Journal of Clinical Endocrinology & Metabolism, 2005
https://academic.oup.com/jcem/article/90/5/2595/2836735
10. Clomiphene citrate for male hypogonadism and infertility: A comprehensive review
Andrology, 2020
https://www.liebertpub.com/doi/full/10.1089/andro.2020.0005
11. The Use of HCG-Based Combination Therapy for Recovery of Spermatogenesis After Testosterone or Anabolic-Steroid Use
Wenker EP, Dupree JM, Langille GM, Kovac JR, Ramasamy R, Lamb DJ, Mills JN, Lipshultz LI
Journal of Sexual Medicine, 2015
https://onlinelibrary.wiley.com/doi/abs/10.1111/jsm.12890
12. Exogenous testosterone: a preventable cause of male infertility
Crosnoe LE, Grober E, Ohl D, Kim ED
Translational Andrology and Urology, 2013
https://tau.amegroups.org/article/view/2249/html