Testicular shrinkage on TRT: what the orchidometer actually shows

What did @drleprovost actually say?

The video makes two core claims: first, that an orchidometer can help assess hypogonadism by measuring testicular size, and second, that testosterone replacement therapy (TRT) causes testicular shrinkage in most patients, typically noticed "after about two to three months." He also mentions that medications exist to offset this side effect, without naming them. The tone is measured and clinical, which is either reassuring or convenient, depending on how you look at it.

To his credit, he frames the shrinkage as variable, noting "everybody's going to have a different idea as to what that really means." He doesn't catastrophize it, and he doesn't dismiss it. That's a reasonable middle ground for a short-form video.

Does the science back this up?

Yes, on the shrinkage claim, the science is pretty clear. Exogenous testosterone suppresses the hypothalamic-pituitary-gonadal (HPG) axis, which reduces luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Without LH stimulation, the Leydig cells in the testes stop producing endogenous testosterone, and testicular volume decreases. This is not controversial.

A 2013 study by Coviello et al. in the Journal of Clinical Endocrinology and Metabolism confirmed that exogenous testosterone suppresses intratesticular testosterone, which is the driver of spermatogenesis and, by extension, testicular volume maintenance. A 2021 review by Ramasamy et al. in Translational Andrology and Urology further confirmed that testicular atrophy is a well-documented consequence of TRT, particularly with injectable and implantable formulations. The two-to-three-month timeline he cites is plausible, though the research shows this can vary substantially between individuals.

The orchidometer claim is also grounded in real clinical practice. Prader orchidometers have been used since the 1960s to assess testicular volume, though they're considered a rough screening tool, not a diagnostic instrument on their own.

What did they get wrong (or right)?

He got the core biology right. Exogenous testosterone suppresses the HPG axis, testicular volume drops, and medications like human chorionic gonadotropin (hCG) or clomiphene can partially offset this. That's accurate.

What he got fuzzy is the hypogonadism-to-orchidometer link. Using testicular size to infer hypogonadism is a screening proxy at best. Testicular volume can be normal in secondary hypogonadism (where the problem is in the pituitary or hypothalamus, not the testes themselves). A 2018 paper by Mulhall et al. in the Journal of Urology, part of the AUA guidelines update, is explicit that serum testosterone measurement, not physical exam alone, is the standard for diagnosing hypogonadism. Treating orchidometer readings as a stand-in for endocrine workup is a shortcut that could mislead viewers.

He also drops the "whole nother story" line about medications that offset shrinkage without saying what they are. That's a content hook, not clinical education. Patients deserve to know that hCG is the most commonly used agent for this purpose, even in a brief mention.

What should you actually know?

If you're on TRT or considering it, testicular atrophy is a real and expected side effect. It's not dangerous in itself, but it can affect fertility significantly. A 2017 study by Bernie et al. in Fertility and Sterility found that men on TRT had dramatically reduced sperm counts, often to azoospermic levels, and recovery after stopping TRT is not guaranteed or quick.

The medications that can help include hCG, which mimics LH and maintains intratesticular testosterone, and selective estrogen receptor modulators (SERMs) like clomiphene. Neither fully prevents testicular volume loss in all patients, and neither is a simple fix.

• Testicular atrophy from TRT is caused by HPG axis suppression, not a direct drug toxicity.
• An orchidometer is a useful screening tool but cannot diagnose hypogonadism on its own.
• If fertility matters to you, TRT is not the right first-line choice, period.
• Talk to a provider about hCG co-administration before starting TRT, not after you notice shrinkage.

The video is largely accurate but leaves out the fertility implications entirely, which is the part most men in their 30s and 40s probably need to hear most.