Neither soy nor isoflavone intake affects male reproductive hormones: An expanded and updated meta-analysis of clinical studies
Reed, K. E., Camargo, J., Hamilton-Reeves, J., Kurzer, M. & Messina, M.Reproductive Toxicology, 2021DOI: 10.1016/j.reprotox.2020.12.019
Pooled 41 clinical studies covering more than 1,700 men and found that neither soy foods nor isoflavones changed testosterone or estrogen levels at any dose. The clearest evidence against the myth that soy feminizes men.