What is a good website for drug/supplement interactions

For example, zinc can cut down on copper levels and you need a proper ratio of them. Alpha lipoic acid can cut down biotin levels by competing with it. So if you take one you are supposed to supplement with another. Aspirin and Ginkgo Biloba can cause dangerous levels of blood thinning.

Where can a person find a website that goes in depth on topics like these?

I can’t really confirm that supplements are covered in any particular depth, but I’ve been very happy with the information served up by:

Drug Interactions I

Drug Interactions II

Drug Interactions III

Also try this one:

http://www.lef.org/