Information for patients

Testosterone replacement therapy for the treatment of male hypogonadism – results from the largest international study

1493 patients from 23 countries joined this study; of these 1123 completed a series of five injections of supplementary testosterone.

All patients had lower than normal levels of testosterone at the start of treatment. The average age of men taking part was just over 49 years. Some suffered from other conditions such as hypertension (high blood pressure) and diabetes.

The findings of this study were presented to the Men’s Health World Congress, 2010 held in France.

Key findings

  • Increasing testosterone levels to normal levels by a series of injections improved the symptoms of testosterone deficiency
  • The percentage of patients who reported “low” or “very low” levels of sexual desire/libido fell from 64% at the start of treatment to 10% by the end
  • Before treatment 67% of patients said they had moderate, severe, or extremely severe erectile dysfunction (ED). This decreased to 19% after treatment with 61% of patients with some degree of ED reporting an improvement
  • Treatment also improved patients ability to concentrate as well as their mood
  • The average waist measurement of the patients fell from 100 cm to 96 cm
  • Some patients (6%) reported side effects which were mostly mild to moderate in severity
  • Overall 89% of patients said they were “satisfied” or “very satisfied” with their testosterone replacement treatment

Source: IPASS: Final data from the worldwide largest study of the tolerability and effectiveness of injectable testosterone undecanoate (TU) for the treatment of male hypogonadism involving 1493 patients. M Zitzmann, JU Hanisch, A Mattern, M Maggi. A presentation to the Men’s Health World Congress 2010.

Background information

Testosterone is an essential male hormone, produced in the testes in a man, which helps to keep our minds and bodies functioning properly. In particular, testosterone enables a man to have erections and experience sexual desire (libido). It also helps to maintain:

  • Muscle strength and function
  • Healthy bones
  • Positive mood
  • Physical energy
  • Male hypogonadism is a condition associated with low testosterone (T) levels.

The impact on men’s health of low testosterone can include:

  • Lack of energy
  • Depression
  • Loss of libido
  • Loss of facial and body hair
  • Changes to body composition (for example, low muscle mass and increased fat mass)

Men with low testosterone are also at increased risk of:

  • Cardiovascular disease
  • Diabetes and metabolic syndrome
  • Osteoporosis

Restoring testosterone levels in men (with lower testosterone levels than normal) can potentially lead to some beneficial effects. Researchers found that patients experienced some of these benefits in this large international study.

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Last updated: 2019