Evening Primrose?!

Ha
Who is taking this now, or took this with previous pregnancies? My sister suggested I start taking it, I'm 38.3weeks, haven't started taking it yet though. 
What happens when you take it orally? Anyone have side effects? 
What happens vaginally? 
Does anything come out?? 
Is it working for you? I was only 30% effaced at my 38week visit, not dialated at all, baby is very low but not completely engaged yet.