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Testosterone injection improves sexual function in Korean men with low testosterone and erectile dysfunction

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Testosterone replacement therapy with the long-acting injection formulation of testosterone undecanoate has been shown to return testosterone levels to normal and improve erectile function in European men with low testosterone (also known as hypogonadism) and erectile dysfunction (ED). However, there has been little information about how safe and effective the testosterone undecanoate injection is in Asian men. This study treated 133 Korean patients aged 42 to 75 years (average age 54 years) who had ED and low testosterone. The men received a series of three testosterone undecanoate injections; one at the start of the study then again after 6 and 18 weeks.

Key Findings

The testosterone injection:

  • Increased testosterone levels to normal by week 12 of the study and maintained the improvements throughout the study
  • Significantly improved erectile function as assessed by a number of authoritative questionnaires designed to reliably measure erectile function and the effects of treatment for ED (Figure)
  • Improved the men’s cholesterol levels.

Treatment caused few side effects of no more than mild severity, and the injection did not cause side effects at the injection site

Source: Moon DG, Park MG, Lee SW, et al. The efficacy and safety of testosterone undecanoate (Nebido®) in testosterone deficiency syndrome in Korean: a multicenter prospective study. J Sex Med 2010;7(6):2253-2260.

Background information

The long-acting injectable formulation of testosterone undecanoate brings testosterone levels back into the normal range and keeps them there with only four or five administrations per year, instead of injections every two or three weeks, as required with earlier injectable formulations. Without the peaks and troughs experienced with earlier conventional testosterone injections, the long-acting injection is a safe and convenient means of reversing the symptoms of low testosterone.

This study in Korean men with low testosterone and ED confirms that the excellent results seen in clinical trials of this preparation in Europeans with hypogonadism can also be expected in Asian populations. The injection was effective, safe and well tolerated, normalizing testosterone levels and maintaining a stable concentration throughout the study, while improving erectile function. As well as a beneficial effect on total cholesterol levels, there was some evidence of improvements in glucose control, particularly in men with high initial levels of glucose in the blood.


Last updated: 2019