When are you taking it and for what purpose? I have heard of many pregnant women taking it towards their due date to soften the cervix, and in this case, I would recommend checking w/ your healthcare provider for doseage that's right for you and waiting until the right time to take it. If you are taking during non pregnancy for hormonal health, and following directions, then I am not aware of any side effects.
Are there any disadvantages of taking Evening Primrose Oil?
I hope not I have taken it for years for PMT.