Will evening primrose oil help if I’m already dilated?

When did you start taking primrose oil? I’m currently dilated to 2-3cm and baby has dropped. I really don’t want to go past 40 weeks so I was wondering if it would help me start something since I’m already dilated? I never used it last pregnancy so I would love to hear from women who have used it and what it did for them and if you took it orally or vaginally.

And what measurement did you take? 1000mg, 2000mg?