Time-course of biological effects of testosterone replacement therapy

Onset of effects of testosterone treatment and time span until maximum effects are achieved. Saad F, Aversa A, Isidori AM, et al. Eur J Endocrinol 2011;165(5):675-685.

• the use of an active treatment group was compared with a matched placebo or control group
• a description of the time course of the effect of active treatment was included, and
• randomization, adherence to protocol and single/double-blind study design was reported.

Only full articles published in peer-reviewed medical journals were included.

What is known

The goal of testosterone replacement therapy (TRT) in hypogonadal men is to safely restore testosterone to normal physiological levels to alleviate symptoms associated with testosterone deficiency and to improve health, well-being and quality of life.^2,3 The profound physical and/or mental changes in the patient undergoing TRT make the management of hypogonadism rewarding and satisfying for patient and physician alike.¹ An understanding of when the effects of testosterone can and should be expected is useful to the attending physician and of interest to the patient. Furthermore, information on the time-course of the biological effects of testosterone is relevant for the design of clinical trials of TRT. However, while the spectrum of effects of testosterone is well documented, the same level of attention has not been given to the time course for the onset of treatment effects and the time span required for the achievement of full expression.

It is clear that the effects of TRT appear at different rates (Figure). Although the full benefits of TRT may not appear until after the first year of treatment, improvements in libido, erectile function, mood, depression and quality of life typically occur earlier. This is also true for changes in PSA and haematocrit. Finally, the studies selected for the present analysis provided testosterone treatment that delivered adequate doses and delivery of testosterone. The use of sub-optimal therapeutic regimens or the inappropriate use of TRT in eugonadal men or those with biochemical hypogonadism in the absence of clinical symptoms are likely to show different time courses of effects.

What this article adds

This comprehensive review provides a basis for a better understanding of the physiology of testosterone action, and is a resource informing the monitoring of the effects of TRT and in counselling the patient on when an effect can be expected and when its maximum has been reached.

Click here for the Testosterone Effects Tool – a visual display of when the effects of testosterone treatment can be expected to occur.

References

1. Saad F, Aversa A, Isidori AM, et al. Onset of effects of testosterone treatment and time span until maximum effects are achieved. Eur J Endocrinol 2011;165(5):675-685.
2. Bhasin S, Cunningham GR, Hayes FJ, et al. Testosterone therapy in men with androgen deficiency syndromes: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab 2010;95(6):2536-2559.
3. Buvat J, Maggi M, Gooren L, et al. Endocrine aspects of male sexual dysfunctions. J Sex Med 2010;7(4 Pt 2):1627-1656.

This Research News article reviews an open-access article available in full from the European Journal of Endocrinology at: http://eje-online.org/content/165/5/675.long. The original article may be referred to for additional detail and supporting references for the statements summarised in this article, which are too numerous to cite in full.