His scientific work focuses on the diagnosis and treatment of hypogonadism (testosterone deficiency), fertility disorders, and age-related hormonal changes. As a co-author of the European guidelines on testosterone deficiency, he has actively contributed to shaping modern treatment strategies for affected men. His research investigates, among other things, the long-term effects of testosterone therapies, the relationship between hormonal balance and metabolism, and the impact on cardiovascular health.

In addition to his academic and clinical work, Professor Dr. Zitzmann is a sought-after speaker and author of numerous specialist publications. His scientific findings have contributed to a deeper understanding of testosterone and its role in the male body, enabling well-founded medical care. For his outstanding work, he was awarded honorary membership in the Royal Society of Medicine.

Relevant publications:

Saad, F., Aversa, A., Isidori, AM, Zafalon, L., Zitzmann, M., & Gooren, L. (2011). Onset of effects of testosterone treatment and time span until maximum effects are achieved.European Journal of Endocrinology,165(5), 675–685.https://doi.org/10.1530/eje-11-0221

Zitzmann, M. (2009). Testosterone deficiency, insulin resistance and the metabolic syndrome. Nature Reviews Endocrinology, 5(12), 673-681.

Zitzmann M. (2020). Testosterone, mood, behavior and quality of life.Andrology,8(6), 1598–1605.https://doi.org/10.1111/andr.12867

Traish, AM, Miner, MM, Morgentaler, A., & Zitzmann, M. (2011). Testosterone deficiency.The American journal of medicine,124(7), 578–587.https://doi.org/10.1016/j.amjmed.2010.12.027

Zitzmann, M., Michel, MC, & Sperling, H. (2024). Testosterone replacement therapy and possible side effects.Urology (Heidelberg, Germany),63(11), 1103–1110.https://doi.org/10.1007/s00120-024-02455-8