Negative feedback loop for testosterone

Hi rachelyoonji

Anabolic steroids causes infertility due to sperm not being produced properly. Specifically, anabolic steroids causes oligozoospermia - presence of an abnormally low number of viable sperm in a semen. Or, azoospermia - medical condition of a man whose semen contains no sperm. This is because steroids throws the process out of loop, ultimately causing abnormalities in sperm motility and morphology. Remember how steroids work at the DNA-level; they're technically transcription factors -- too many and you have proteins likely being produced incorrectly.

The article below discusses this in more detail. Let me know if you have any follow-up questions.

That's at the cellular level. What about anabolic steroids induced hypogonadism? When people take steroids, the body stops producing its own testosterone. This results in an imbalance in androgenic hormones, leading to testicular atrophy and lower sperm count. In rats, testosterone use leads to the degeneration of the tubular elements and to a lesser extent is caused by involution of the Leydig cells.

Thanks so much for your help!

I just have one question though- if synthetic testosterone so closely resembles human-made testosterone, shouldn't that be fine? (I just don't understand why people can't just keep using AAS forever and not rely on self-made testosterone.

They can for sure, but the body knows exactly how much to release and when. When it's injected, you're relying on your memory when to take and when not to. Imagine being 75 years old, your memory won't be as sharp as it is when you're young. The process is controlled automatically, much like the way we breath and how our heart beats. We don't conscience think of it. In addition, the balance is so fragile that depending on the time of day, evening vs. morning, testosterone levels fluctuate drastically.

Generally, you can't mess with how our bodies evolved. Evolutionary speaking, we were naturally selected to experience a decrease in testosterone even if we became fathers. I know, that sounds odd, doesn't it?

Studies shows that becoming a father leads to a sharp decline in testosterone, suggesting that although high levels of the hormone may help men win a mate, testosterone-fueled traits such as aggression and competition are less useful when it comes to raising children.