Hi Ashley
I had some trouble finding it too. It is more commonly used for induced lactation, which I guess isn't so common.
I bought some capsules (just goat's rue), the Mother Love brand, through the local breast-feeding centre, I also found them in Whole Foods. Motherlove also sells their stuff online.
Now I've tried it, I'm thinking of buying the powder in bulk and making my own caps, because the pre-mixed caps were quite expensive.
Hope this helps
Lara