I use this and I thought I would share. I take vitamins and supplements, along with some natural herbs etc and constantly check to see if I have any interactions or risks etc...This checker helps with not only supplements but with prescriptions as well.
I list everything I take (vitamins, supps, herbs, scripts etc...) and hit the button and then if I do have any interactions or warnings then I check with my pharmacist (personal friend) or GP (mine is slightly retarded but a decent guy)
http://www.drugs.com/drug_interactions.htmlI'm of the mind you can never be to careful and I like to double check everything. Drugs.com is a reputable source to look up information to ask your medical professionals about. Knowledge is power and this has been a great tool for me.
I hope it's OK to share this URL, if not I don't take offense to the edit!
Enjoy
Eric