Evening Primrose Oil

Amanda • We are a blended family of 7. This will be our first together. Super excited.
So since I tried Castor Oil last week and it didn't work. I went to my appt Friday and my midwife suggested that I try evening primrose oil. I'm showing signs of progression. As of Friday, I was 80% effaced and my cervix is super soft and elastic. This is my fourth child. She compared my cervix to a very ripe banana you would use for banana bread. Lol. So I got some EPO, poked a hole in one tablet and inserted it vaginally tonight. I'm not sure how fast it will work and whether it work after one try or not. What's everyone's experience with EPO?