Digitalis purpurea also contains loliolide, a potent ant-repellent which was once used as an insecticidal disinfectant for walls in the Forest of Dean, England. Medicinal uses Foxgloves are a source of digitoxin, a glycoside used in the drug digitalis, which has been used as a heart stimulant since 1785. It is also well-known for its toxicity, and ingestion of the leaves (usually as a result of misidentification for comfrey, Symphytum officinale) can result in severe poisoning.