Daddies- I'm not sure where u live, I'm in Canada, but here the health food stores sell it and apparently even a lot of grocery stores so it's pretty readily available.
From what I've read it doesn't "induce" labour. It just helps your cervix prepare for labour/birth. Apparently allowing it to stretch better and dilate better and such.
Who knows if it actually works but after being told my lil guy has a very large head I'm going to try it!