SIG™ The herbs in this supplement - echinacea, golden seal, burdock, dandelion, and capsicum - have been used traditionally to support better health. Item #15907 100 Tablets SIG™ is a natural immune enhancer.* Key Herbs: • Echinacea nutritionally supports the lymph glands, important components of the body's defense system.* • Burdock is a natural blood cleanser..