Natural Remedies for Anxiety/Panic?

I’m looking for natural remedies for anxiety/panic attacks. Its for a friend, drugs are NOT an option. I stopped by the health food store today, but there were so many options. I want to recommend something effective. I have heard good things about Rescue Remedy, and so bought some of that. Has anyone had good results with this or anything else? She has panic attacks related to severe social anxiety. Also, if anyone knows of a good book or website where I could learn more about panic remedies, that would be much appreciated. Thanks! -Neb