I've been brewing it for a couple of years, getting the ingredients from the local natural foods hippie store. Wintergreen seems to be hard to find in a nice fresh state, I think because it is not used in much else than root beer. Sassafras, sarsaparilla, licorice, all widely available. I've also used chicory, dandelion root, orris root, astragalus root, ashwagandha root, angelica root, and a few others, all pretty available. You could also try web sources such as Wild Weeds or Mountain Rose Herbs.