Wintergreen (Gaultheria procumbens)

Wintergreen, also known as dwarf wintergreen, is a member of the heath family native to eastern North America. This evergreen dwarf shrub, with its decorative red berries, is also prized here as a garden plant.
The leaves of this plant were used in traditional Native American medicine to treat fever, headaches, back pain, rheumatism and respiratory infections.
The key active ingredients in wintergreen leaves are essential oil, polyphenols, procyanidins and chlorogenic acid. The essential oil is highly toxic, which is why precise dosing is crucial. It consists of 96–99% methyl salicylate, a chemical relative of aspirin, and should never be taken internally. Even for external use, wintergreen oil should only be used in diluted form.
It has anti-inflammatory, antimicrobial, analgesic, antispasmodic, astringent, cell-protective, diuretic and local circulation-promoting effects.
Wintergreen oil is primarily used externally as a painkiller for musculoskeletal disorders, rheumatism and muscle tension, and in veterinary medicine also for mastitis.