In moderation, soy milk is safe for men to consume. Although some people are concerned that soy milk may lower testosterone levels and induce female characteristics, soy milk does not significantly influence a man’s hormone levels. In fact, soy may protect men against prostate cancer.
Compared to other milk alternatives, soy milk contains the highest concentration of protein: up to 11 grams per cup. Fortified soy milk also provides a significant amount of vitamin D, vitamin B12 and calcium. Soy milk can be found in the refrigerated section near regular milk in most grocery stores, as of 2014, but it can be stored at room temperature if unopened. Once opened, it should be used within five days.