Traditional Use References Eases the pain of nerve conditions such as injuries to fingers or toes. Cold Sores. Shingles. Herpes virus. Very sore paper cuts, puncture wounds eg needle pricks. Minor Burns. The leaves and flowers of St Johns Wort contain special glands that release a red oil when pinched. Early Christians named this plant in honour of St John the Baptist. They say the red oil was first seen on the anniversary of St Johns beheading.