Patients can successfully request hormone tests by describing subjective declines in energy, focus, or athletic performance compared to their past selves. This provides the necessary clinical justification for the lab work without requiring a pre-existing diagnosis.

The impact of caloric restriction on testosterone is context-dependent. While it can improve testosterone levels in men with obesity or metabolic syndrome, the same dietary stress will likely decrease testosterone in young, healthy, lean men.

While dry saunas are effective for detoxification, the heat can damage fertility. Experiments show that applying ice packs to the testicles during sauna sessions not only mitigates this damage but can lead to a rebound effect, resulting in the highest-ever recorded levels of sperm count, motility, and morphology.

Instead of relying on supplements, performance medicine uses FDA-approved drugs off-label to optimize health. The predicted stack includes testosterone (muscle), tirzepatide (fat loss), tesamorelin (recovery/sleep), tadalafil (blood flow), and oxytocin (stress), each drastically outperforming its supplement counterpart for a specific health goal.

When addressing hormone imbalances, start at the base of the "hormone pyramid." Optimizing foundational hormones like cortisol (stress) and insulin (blood sugar) is essential, as they directly impact thyroid function and sex hormones like estrogen and testosterone.

While low testosterone can cause poor sleep, starting TRT can also lead to sleep issues. It drastically increases the risk of sleep apnea and can initially put the body into a hypersympathetic (fight-or-flight) state, disrupting sleep patterns.

Sperm has a turnover cycle of about three months. Therefore, men planning for children should implement a three-month period of improved health—reducing alcohol, exercising more, and eating better—to ensure their sperm are of the highest quality at the time of conception.

Dr. D'Agostino gives his aging, neutered dogs a Selective Androgen Receptor Modulator (SARM) to stimulate muscle protein synthesis and maintain vitality. This approach is analogous to Testosterone Replacement Therapy (TRT) in humans, aiming to counteract the loss of skeletal muscle mass associated with aging and hormonal changes.

Contrary to popular belief, women's bodies contain substantially more total testosterone than estradiol. This misunderstanding arises because tests use different units (nanograms vs. picograms) or focus only on "free" testosterone, understating its overall prevalence and importance.