Making sperm is, in large part, what testosterone is for. Which is why it is ironic when a man who doesn't need it starts taking it anyway: his brain registers an unusually high level of the hormone in his blood, concludes his body has made too much, and sends the order to stop. The testes go silent. Sperm production goes off with them.
Testosterone is having a moment. It is all over social media, gym culture and wellness forums, sold by online labs, gym contacts and telehealth services, and the information surrounding it ranges from oversimplified to outright dangerous. Men are taking more of it than ever, in pursuit of feeling more like men. In doing so, they may be telling their bodies to stop producing it themselves.
Here is what the science says – what testosterone does, who genuinely needs treatment, and what it can cost the men who take it without needing it.
How does taking testosterone stop sperm production?
Your body regulates testosterone the way a thermostat regulates heat. When the brain detects abnormally high levels of the hormone in the bloodstream, it sends a signal to the testes to stop producing it naturally. The testes effectively go offline, and because sperm production depends on what happens inside them, that shuts down too.
