Four herbs.
D019587:Dietary Supplements / Q000592:standards*; D020900:Echinacea / Q000627:therapeutic use; D020441:Ginkgo biloba / Q000627:therapeutic use; D006801:Humans; D020902:Hypericum / Q000627:therapeutic use; D007880:Legislation, Drug; D005894:Panax / Q000627:therapeutic use; D008517:Phytotherapy; D010946:Plants, Medicinal; D014481:United States