For guys without hypogonadism, a wait-and-see approach may make the most sense. "We just don't have the data to prove that raising testosterone in men who already have normal levels confers any real benefit," says Dr. Robert Mordkin , a urologist in Arlington, Virginia. Furthermore, Mordkin adds, "Natural waxes and wanes of testosterone as we age may have some not yet entirely understood protective effects." In addition to making us better fathers, as the Northwestern study infers, declining testosterone "may lower our vulnerability to prostate cancer at a time in our lives when we're at the greatest risk for it." That said, if you have classic symptoms of hypogonadism – low libido, fatigue, erectile dysfunction – "it's probably reasonable to check your testosterone. And for those guys whose blood levels come under definitions of low testosterone, it's probably reasonable to try the therapy for a while. But that's very different from saying testosterone is the fountain of youth."
If a young man's low testosterone is a problem for a couple trying to get pregnant , gonadotropin injections may be an option in some cases. These are hormones that signal the body to produce more testosterone. This may increase the sperm count. Hedges also describes implantable testosterone pellets, a relatively new form of treatment in which several pellets are placed under the skin of the buttocks, where they release testosterone over the course of about three to four months. Injections and nasal gels may be other options for some men.