Dried burdock, astragalus, and dandelion root are available at herb stores or online. (marthastewart.com)
I bought some dried mint from a local herb store in town and I steeped the mint into an oil and then tried various quantities in the recipe to make it minty enough. (homemademommy.net)
Topical comfrey preparations - namely ointments and liquid extracts - are available from specialized health stores and online herb stores. (herbazest.com)