Testosterone

Testosterone is a sex steroid hormone with effects on behavior, sexual function, and many body tissues. Its role depends on the person and on the balance with other hormones.

• Behavior and motivation: Higher testosterone is associated with less anxiety, more novelty seeking and competition, and increased libido and desire to seek sex. Competing itself can raise testosterone in the short term, whether or not someone wins. 1 2
• Sexual function: Testosterone supports sex-seeking in both men and women, but estrogen also matters—very low estrogen can reduce men’s libido. 3
• Sleep and health: Sleep-disordered breathing and poor sleep are linked with lower sex-hormone levels; adequate deep and REM sleep support hormone optimization. 4
• Training: Resistance training can increase the body’s anabolic environment; the discussion describes adrenal testosterone release during resistance exercise in women, though the magnitude is smaller. 5
• Testing and treatment: Total testosterone alone may not tell the whole story because much of it is bound to SHBG or albumin. Testosterone therapy requires individualized assessment and medical monitoring; potential concerns discussed include acne, hair loss, mood changes, fertility, and cardiovascular or lipid issues. 6 7