[tropo]

I would not expect a better reaction from actual, mammalian estrogen. It doesn't work that way with opioids: carfentanyl is a whole lot more powerful than dynorphins, enkephalins, endorphins, endomorphins and nociceptin.

Also, quantity matters. Plants might produce a lot more than mammals do.

In any case, the breast growth on males is no joke. That is just the affect on adults, who are far less susceptible than babies. However it works, soy is a serious hazard and should have the GRAS (generally recognized as safe) status removed.