Soy Protein vs. Whey Protein

Whey protein is found in milk along with Casine protein and Soy protein is from Soy.

Here's some consolidated information on different types of protein powders: http://examine.com/supplements/Protein+Supplement/

According to this source WHEY protein is of a "higher" quality: http://en.wikipedia.org/wiki/Protein_Digestibility_Corrected_Amino_Acid_Score

I honestly wouldn't worry too much about the difference , just remember that protein powder is not a miracle supplement but just a macro nutrient that provides the building blocks for muscle growth.

Good Luck !

I'm no expert, but I get Bolthouse Farms Chocolate Protein Plus and on the label it says it has both soy and whey proteins and that whey protein is absorbed faster to satisfy immediate nutritional needs while soy absorbs more slowly for sustained benefits.