I should also say that I didn't have much side effects from Lynparza other than fatigue. At the beginning, I did have some nausea about 30 minutes after taking it, but it would subside on its own within another 30 minutes.

Hi SarahMolina - I took Berberine sporadically while on Lynparza (400mg/day). I did not notice a difference in how I felt from the days with and w/o Berberine. I'm off Lynparza now and also not taking the Berberine, but I have kept up with my other vitamin/mineral regimen.

I don’t know about Berberine but I’ve been on Lynparza for almost 2 years now. Side effects are different for everyone. Most people have fatigue and some nausea. Make sure you have some Zofran handy in case you need it when you first start out.
Let us know if you have problems with Lynparza we can make some suggestions that can help.