I was thinking about taking collagen, just in general (I still am undecided about herbs, right now I'm just massaging), but I was wondering if any one knows if it interacts with birth control pills?

Absolutely no way.
That would be like saying that eating fish/steak/chicken
would interfere with birth control.
Collegen/gelatin was plentiful in the good old fashion stews and
soups that our grandmothers would make.

collagen is also all throughout your body!! it does not produce a hormone, so it couldnt interact with your birth control anyway...

so go ahead and add!! this is one i am SURE of...