Traditionally, men who want to maintain fertility potential or are trying to achieve a pregnancy with their spouse/partner have been deterred from being on testosterone replacement for low testosterone. The reason for this is that all of the classic testosterone replacement medications including topical gels, injections, patches, and pellets, suppress the signaling command hormones coming from the pituitary gland. Follicle stimulating hormone (FSH) and luteinizing hormone (LH) are the signaling hormones that tell the testicles to do their jobs of sperm and testosterone production. In men that are on exogenous testosterone replacement of other the traditional kinds, the FSH and LH suppress down to zero which means there is no longer signaling to the testicles to work, so the testicles essentially stop working, suppressing sperm production down to zero or extremely low levels.
Classically, in men who wanted to maintain fertility potential, they have been offered treatment with medications such as selective estrogen receptor modulators such as clomiphene citrate or tamoxifen, or with hCG. These drugs stimulate the man’s cells to produce testosterone in a way that does not suppress sperm production; however, a fair percentage of these men anecdotally do not get optimal symptom responses, especially in libido despite having normalized testosterone levels in the blood. Interestingly, most of these men get significant improvements in symptoms such as libido when changed to testosterone replacement therapy.
Dr. Parviz Kavoussi recently was asked to host an educational video on Natesto, the first FDA approved intranasal gel for testosterone replacement. This modality of treatment is very similar to the natural physiology of testosterone pulses in the man’s body. Therefore, it has been shown to be the only testosterone replacement therapy that does not significantly suppress LH and FSH, so the command signals keep telling the testicles to work while the body is receiving testosterone replacement. Dr. Kavoussi states, “This is quite an amazing aspect of how this medication works. The obvious next question is if we are still signaling the testicles to work, are they still making sperm? A clinical trial out of the University of Miami, is showing just that. Men can be treated with Natesto as the first form of direct exogenous testosterone replacement, to get optimal symptom responses, and not suppress sperm production.”