Improving Male Sexual Health, Function & Fertility | Dr. Michael Eisenberg

Semen analysis looks at volume, sperm count, motility, morphology, and sometimes DNA fragmentation/epigenetics. Men with lower semen quality have higher rates of cardiovascular disease, diabetes, cancer, and mortality. About 15% of men have abnormal semen parameters and ~1% have no sperm in the ejaculate. Eisenberg calls semen analysis a potential “sixth vital sign,” arguing it should be measured more routinely, even in young men.

Roughly 50% of men over 40 and 15–20% under 40 have some ED. Less than 10% of ED is endocrine‑driven; the vast majority stems from blood flow issues (hypertension, diabetes, atherosclerosis), neural injury (pelvic surgery, cancer treatment), or lifestyle. First-line therapy is oral PDE5 inhibitors (Viagra/sildenafil, Cialis/tadalafil, etc.), which help ~60–70% of men; if those fail, options include urethral suppositories, penile injections, and ultimately penile implants. Eisenberg emphasizes, “As long as you have a penis, we can make it hard.”

Excess body fat increases aromatase, converting testosterone to estrogen, and insulates the testes, impairing hormone production and spermatogenesis. Yet Eisenberg routinely sees obese men with normal T and fit men with very low T. He stresses objective testing over visual judgment. Step count and overall activity show a positive association with testosterone across BMI ranges, and healthier men (fewer comorbidities) have better testicular function.

Saunas, hot tubs, seat warmers, laptops on the lap, and prolonged cycling can raise scrotal temperature and impair spermatogenesis. Sperm production is far more heat-sensitive than testosterone, but chronic heat still risks reduced function. Eisenberg suggests minimizing direct heat, using a desk instead of lap for laptops, and possibly using cooling packs in saunas (while avoiding frostbite). Cycling itself is heart-healthy, but long hours in the saddle can create both heat and nerve/blood vessel compression issues.

Exogenous testosterone suppresses pituitary LH/FSH, drastically reduces intratesticular testosterone, and can drop sperm counts to near zero. About 1 in 20 infertile men in Eisenberg’s clinic are infertile specifically because of testosterone therapy, often started without proper counseling. HCG (500–1000 IU every other day) can partially maintain sperm production on TRT, and clomiphene can raise endogenous testosterone without directly suppressing spermatogenesis, but neither is perfect. Eisenberg prefers the term “testosterone therapy” over “replacement” because many users are augmenting, not replacing.