I didn't want to take the time to grow my own (seeing what a brown thumb I can sometimes have when sproutiing
) and there's no local source of wheatgrass juice, but I found a very good online source, that grows the wheat outdoors and flash freezes it. It ships frozen overnight, and you keep it frozen until use. It tastes really good! Fairly sweet, and not "too green' (like the unfortunately too ambitous green juice I made this morning...blech!). www.dynamicgreens.com
I've been using it for the last week and a half, and sharing it with my eldest, diabetic cat, in hopes that it might help him as well. I put a couple of the frozen chunks in a glass of water, so it is also watered down a bit (I don't know if I'd want to take even this sweeter wheat grass as a straight shot...it also seems more beneficial to hold the juice in your mouth for a while before swallowing, to allow some absorption through the mucus membranes of the mouth).
They claim that some reactions to wheat grass may not be 'cleansing reactions," but rather an allergic reaction to molds that may be on the grass (especially if it is grown indoors). Also, some people can be allergic to grass (it's not a gluten allergy to wheat that is the problem, because there is no gluten in the grassy part of the plant, but an actual allergy to grass).