Metformin and herbal supplements?

Amy
Hi!
​I have been given a prescription for metformin so will start taking in a few days, up to now I have been taking maca root and tribulus along with pre natal vitamins.
​My question is has anyone taken metformin with maca root? I will be stopping the tribulus but the other benefits from maca have been great (more energy and generally feeling better in myself) so if they're safe to take together I'd continue with these.
​My doctor didn't know when I asked so if anyone has any experience with these id love to hear about it 
​Thanks!!