http://forum.myprotein.co.uk/showthread.php?t=17488

"A group of researchers representing Miami Research Associates recently compared the effects of supplementation with four different protein sources--soy concentrate, soy isolate, a soy/whey blend, and whey protein--on hormone levels, and body composition in 20 men (with an average age of 30 years) enegaging in a 12-week resistance training program. Subjects were randomly assigned to receive only one of the four protein supplements and were blinded to the specific protein type they received. All subjects lifted weights three times per weeks and consumed 50 grams per day of the protein supplement that had been assigned to them.

All four groups exhibited similar increases in lean body mass after 12 weeks. There were no differences in testosterone levels among the four treatments. The researchers concluded, "This investigation shows that 12 week supplementation with soy protein does not decrease serum testosterone or inhibit lean body mass changes in subjects engaged in a resistance exercise program."

Don't use soy protein, it's the worst form out there.

somehow, I am still leery of soy

dividing 20 men four ways does not allow you to draw statistical inferences, way too small a sample.

however, this accords with what omen and others have been saying, that fear of soy is overblown.

You're right, Soy doesn't decrease Testosterone levels.

It increases Estrogen levels. Keep that in mind when you go bald and grow tits.

Whey protein after your workout, casein before bed. There is no need for a male to EVER take soy.

what if you want to be gay?