Why are testosterone levels important for fertility? Testosterone is the male sex hormone, and is responsible for producing the characteristic deep male voice, greater muscle mass and hairier body compared to women. Testosterone is a natural steroid that gives men their sex drive, aggression, stamina and physical strength.
Men produce most of their testosterone in the testes, with smaller amounts coming from the adrenal glands. In women, small amounts of testosterone are produced by the ovaries. Men on average have seven time as much in their system as women.
Low testosterone levels can affect all the male physical characteristics adversely, reducing a man’s stamina, sex drive, strength and physical energy. It is also a common cause of erectile dysfunction. Although testosterone peaks at age 20 and then naturally declines, if it declines too far it can interfere with a man’s mental resilience and wellbeing, and with his fertility.
Testosterone plays an important part in sperm production. When the brain uses chemical triggers to prompt testosterone production, it also triggers the production of sperm at the same time. If less testosterone is produced, fewer sperm are produced too. Therefore, anything that suppresses testosterone production will decrease a man’s fertility.
It may seem counter to common sense, but taking testosterone injections has a similar effect of preventing sperm production, because unless testosterone is being produced sperm will not be produced either.
Because the testes are very sensitive to environmental factors, there are a number of external influences that can reduce the production of testosterone, and therefore decrease a man’s fertility.