i recently got back into working out,i had to take a 6 year lay-off due to an injury.i have always made my protein shakes using milk/juice, name brand protein and raw eggs. back then i believe the Whey proteins were concentrates,where-as i now use Whey Isolates...i use top name proteins and mix them together most times. now i will admit that the shakes always caused a small gas problem,(if i remember correctly ,it even became less of a problem after a short time) BUT MY GAS IS JUST PLAIN WICKED SMELLING these days. WHAT IS UP???...i mean ,i can clear out a stadium,it is that bad....also please note,that i always chew about 6 super papaya tabs to help with digestion of the protein.