What is low testosterone?

Testosterone is an essential male hormone produced in the testes that plays a crucial role in the health and well-being of our bodies. Testosterone is responsible for typical male sexual characteristics and is required by all men for a healthy life physically and psychologically. Figure 1 shows the different actions of testosterone in an adult male.

Low testosterone (the medical term is hypogonadism) simply means having a very low testosterone level. It happens when the testes do not function normally or when internal hormone production is out of balance. Low testosterone can occur in men of any age. However, there is a progressive decline in testosterone levels as men age.

Although not a common condition, it is hard to say exactly how many men have low testosterone. Doctors believe that 5 in 1,000 men are living with some form of hypogonadism. The number of men with low testosterone increases with age and as many as 1 in 5 European men over the age of 50 have moderate or severe symptoms of testosterone deficiency.

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Figure 1: Effects of testosterone


Figure: Effects of testosterone

Figure 1: Effects of testosterone

Signs & symptoms

The benefits of testosterone replacement on sexual function, fat and lean body mass and bone density in men with low testosterone are clear. The potential benefits of testosterone replacement in reducing the risk of cardiovascular disease, metabolic syndrome and diabetes are still being investigated.


  • Prevents anaemia


  • Controls sexual function (sex drive, erectile function, orgasm)
  • Reduces lower urinary tract symptoms (LUTS)
Effects of testosterone


  • Improves mood, energy, wellbeing and quality of life
  • Prevents depression

Physical symptoms

  • Increases muscle mass
  • Increases strength
  • Decreases overall body fat mass
  • Decreases belly (visceral) fat mass
  • Increases bone mineral density

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