Testosterone Therapy in Men in Their 40s: A Narrative Review of Indications, Outcomes, and Mid-Term Safety.

Plain-language summary

This narrative review looked at the use, benefits, and safety of testosterone replacement therapy (TRT) in men aged 40-49 with low testosterone. It synthesized findings from randomized controlled trials and large observational studies, focusing on men with biochemically confirmed hypogonadism (total testosterone below 300 ng/dL) and symptoms like low libido or fatigue. The review found that TRT improved sexual function, lean mass, fat mass, and metabolic health, especially when combined with lifestyle changes, with no significant increase in major cardiovascular risks when monitored properly. However, it highlighted the need for careful monitoring of hematocrit levels and prostate health, and called for more research on long-term safety and optimal treatment methods.

Key findings

• TRT benefits men aged 40-49 with biochemically confirmed low testosterone (below 300 ng/dL) and symptoms.
• Improvements include better sexual function, lean mass gains, fat loss, and metabolic benefits like improved insulin sensitivity.
• No significant increase in major heart risks was found with careful monitoring, but erythrocytosis and fertility suppression need watching.
• Long-acting injections carry the highest risk of raising red blood cell counts.