Lactation cookies??

Hi,
I've read on here and other websites about benefits of baking and eating 'lactation cookies' - they all say that the most important ingredient is brewers yeast but I'm having trouble finding any. The article on here suggests health food stores, supermarkets & Big W - I've checked all of these near me but no success; the other option is a home brew supplies shop but they sell it in tiny sachets and you need 2-4 tbspns per batch so not really a good method of buying it. Are there any other names it would be under or does anyone have any other suggestions of where to buy it?? I've found a couple of websites but guess I don't really know how to judge quality - any suggestions would be great thanks!

i got mine from a health food shop inside a shopping centre (so just a basic health food shop not a fancy one). The brand is SF health foods (you can add the www and the dot com dot au and get their website where they list stockists)

That's fantastic, thanks heaps!