Agnus Castus and the pill?

[hornbag]

Someone recommended taking Agnus Castus to help ease PMT so I bought some yesterday (incidently the woman in the shop also told me it can increase you libido!). However its now just occured to me that it might interfere with the effectiveness of the contraceptive pill, which I'm currently taking.
Anyone know anything about this?
TIA

You should not take these two together as this can affect the effectiveness of the pill.

Thanks for that MU -thought as much.
It mentions on the bottle not taking it if pregnant, breastfeeding but nothing else.