Does TRT really shrink your balls?

Testosterone replacement therapy (TRT) is an effective long-term treatment for the symptoms of testosterone deficiency: fatigue, low mood, low sex drive, and loss of muscle mass among them.¹

But as with any medical treatment, TRT isn't always free of side effects. One of the most common questions men ask before starting: will it shrink my balls? The short answer is yes, it can. Here's why it happens, how much, and what you can do about it.

Does TRT shrink your testicles?

Yes. A decrease in the size of your testes, clinically known as testicular atrophy, is a recognised side effect of TRT.^2,3 It doesn't happen to everyone, and for most men it's harmless. But it's worth knowing about before you start treatment.

How much do testicles shrink on TRT?

One study of men on TRT found that testicular volume decreased by an average of 17% over 24 months of treatment.⁴ The same study found that atrophy was more likely to affect men with larger testes, and those who inject testosterone rather than take it in gel or tablet form.

Why TRT can cause testicular atrophy

Your body is a finely tuned machine, and one slight imbalance can easily lead to another. That's what can happen with testosterone deficiency.

When your body isn't producing enough testosterone, you might notice symptoms that seriously affect your quality of life: fatigue,⁵ low mood,⁶ diminished sexual desire,⁷ and many more. If that sounds familiar, the AMS questionnaire is a quick way to gauge your symptoms.

To address the imbalance, many men turn to TRT. Here's the catch: when you add testosterone from an external source, your body senses elevated levels in your system and dials down its own production.⁸

Your hypothalamus then signals to your testes to produce less sperm. Over time, often within around six months of starting treatment, that drop in activity can mean your testes start to shrink.⁴

That may sound worrying at first. For most men on TRT, though, it shouldn't be a medical concern.

Is testicular atrophy something to worry about?

For most men, the main issue is personal. Some simply aren't comfortable with having smaller testes, while others find it knocks their confidence.

In physiological terms, the main effect of testicular atrophy is decreased sperm production.⁹ That matters if you're planning to have children. A lower sperm count doesn't make it impossible to conceive, but it can make it more difficult.

Size is a separate matter from desire: smaller testes have no bearing on your libido. And sperm production typically returns to normal within around 12 months of stopping TRT.⁹

As with any medical treatment, weigh up the benefits and risks with your doctor to decide whether it's right for you. For many men, the improvement in their symptoms makes the trade-off worthwhile.

How to prevent testicular atrophy on TRT

Testicular atrophy won't affect everyone who undergoes TRT. If you're concerned before starting, or you've already noticed changes in the size of your testes, there are options.

Some medicines mimic the action of luteinising hormone (LH), which stimulates the testes and helps support your body's own sperm production.³ Where there's a clinical need, these can be prescribed alongside TRT to reduce the risk of testicular atrophy and a lower sperm count.

The starting point is knowing your numbers. A testosterone blood test gives you and your clinician the full picture before you decide on treatment.

The numan take

Testicular atrophy is a commonly reported side effect of TRT. It's rarely a medical problem, and it's often preventable. Weigh up the risks against the potential boost to your quality of life, and speak to a clinician if you're unsure where to start.

References

^{1 Saad, F., Aversa, A., Isidori, A. M., Zafalon, L., Zitzmann, M., & Gooren, L. (2011). Onset of effects of testosterone treatment and time span until maximum effects are achieved. European Journal of Endocrinology, 165(5), 675–685. https://doi.org/10.1530/EJE-11-0221}

^{2 Ramos, L., Patel, A. S., & Ramasamy, R. (2018). Testosterone replacement therapy for physician assistants and nurse practitioners. Translational Andrology and Urology, 7(Suppl 1), S63–S71. https://doi.org/10.21037/tau.2017.12.09}

^{3 Ide, V., Vanderschueren, D., & Antonio, L. (2020). Treatment of men with central hypogonadism: Alternatives for testosterone replacement therapy. International Journal of Molecular Sciences, 22(1), 21. https://doi.org/10.3390/ijms22010021}

^{4 Suetomi, T., Ichioka, D., Iimura, T., Kojo, K., Ikeda, A., Kimura, T., Kawahara, T., Hoshi, A., Kandori, S., Negoro, H., & Nishiyama, H. (2022). Characteristics of testicular atrophy during testosterone replacement therapy (TRT). The Journal of Sexual Medicine, 19(Supplement_2), S175. https://doi.org/10.1016/j.jsxm.2022.03.398}

^{5 Cavallini, G., Caracciolo, S., Vitali, G., Modenini, F., & Biagiotti, G. (2004). Carnitine versus androgen administration in the treatment of sexual dysfunction, depressed mood, and fatigue associated with male aging. Urology, 63(4), 641–646. https://doi.org/10.1016/j.urology.2003.11.009}

^{6 Celec, P., Ostatníková, D., & Hodosy, J. (2015). On the effects of testosterone on brain behavioral functions. Frontiers in Neuroscience, 9, 12. https://doi.org/10.3389/fnins.2015.00012}

^{7 Tsujimura, A. (2013). The relationship between testosterone deficiency and men's health. The World Journal of Men's Health, 31(2), 126–135. https://doi.org/10.5534/wjmh.2013.31.2.126}

^{8 Khodamoradi, K., Khosravizadeh, Z., Parmar, M., Kuchakulla, M., Ramasamy, R., & Arora, H. (2021). Exogenous testosterone replacement therapy versus raising endogenous testosterone levels: Current and future prospects. F&S Reviews, 2(1), 32–42. https://doi.org/10.1016/j.xfnr.2020.11.001}

^{9 Crosnoe, L. E., Grober, E., Ohl, D., & Kim, E. D. (2013). Exogenous testosterone: A preventable cause of male infertility. Translational Andrology and Urology, 2(2), 106–113. https://doi.org/10.3978/j.issn.2223-4683.2013.06.01}