Hi In terms of muscle-building, is there much difference between different sources of dairy? i.e. Should we just buy the cheapest/best tasting source of whey or casein? And is there any good reason not just to buy ordinary powdered milk (e.g. "Marvel") in the supermarket? Ok, perhaps the fat-free version... I mean is there much difference between different sources of whey? Are some more oxidised or weirdly processed...? And are some more easy to digest? I do seem to have a slight problem digesting milk-based products... and in my experience some are similarly named products are extremely unpleasant to consume, whereas others are fine. with thanks John P.S. I just tried unflavoured version of "Perfect Whey" (from Trec) and it tastes absolutely revolting - just the smell makes me want to vomit. Whereas vanilla "100% whey" (I think from the same company) tastes utterly different - quite good in fact.