Great question. So soy is a phytoestrogen, which is a plant based estrogen. It contains genistein and daidzein, which are a class of compounds referred to as isoflavones. Phytoestrogens act like estrogen (the female sex hormone) within the body so the classic concern is that eating too much may lower testosterone in males. However, the academics have not seen this in studies so I'm not sure that ingesting this orally is going to lead to alterations in testosterone and/or estrogen. It does have anti-carcinogenic properties though so that's a plus. In general, I wouldn't eat it as your primary source of protein but it's fine if you want to mix it in. We probably all eat soy without knowing it if we are eating a lot of commercially available food.