In Hawaii, the plant was boiled to make a poultice to stop bleeding. In China, it was used as an astringent, diuretic and cough remedy. In Central and South America, it was used as a homemade cold remedy to ease lung congestion and inflammation and sore throats. Throughout the Caribbean, an extract from the flowers was used to make a solution to treat eye irritation and infections. Western researchers finally noticed the plant in the 1950's when they learned of a tea Jamaicans were drinking to treat diabetes .
Periwinkles also contain the alkaloids reserpine and serpentine, which are powerful tranquilizers.
Because the alkaloids in this plant can have serious side effects such as nausea and hair loss, it is not recommended that people attempt to medicate themselves with periwinkles. Magic and Medicine of Plants . Pleasantville, NY, Reader's Digest Books. Heywood, V.H., ed. 1993. Flowering Plants of the World .