Time-course of biological effects of testosterone 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.
This article reviewed the published literature of studies analyzing the effects of testosterone administration in hypogonadal men to estimate the onset or time-dependency effects of testosterone.1The analysis consisted of studies performed with testosterone (including testosterone esters and dihydrotestosterone preparations, independent of delivery method) where:
- 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 therapy 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 testosterone therapy 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 testosterone therapy. 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 testosterone therapy appear at different rates (Figure). Although the full benefits of testosterone therapy 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 testosterone therapy 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 testosterone therapy 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.