Wintergreen essential oil is extracted from the leaves of a small evergreen herb. The plant has been used for respiratory conditions such as chronic mucous discharge, but is mainly employed for joint and muscular pain relief from conditions such as lumbago, sciatica, neuralgia, myalgia, etc. The dried leaf and stem are current in the British Herbal Pharmacopoeia as a specific for rheumatoid arthritis.

The essential oil of Wintergreen, being made up almost exclusively of methyl salicylate, is a precursor to common aspirin. This is the reason for the essential oil's analgesic effects, along with anti-inflammatory, anti-rheumatic, antitussive, astringent, carminative, diuretic, emmenagogue, galactagogue and stimulant properties.

This pale yellow oil with an intense sweet-woody aroma should be diluted significantly before topical application - it would be a fine addition to any formulas for supporting joint and muscular aches and pains. Care must be taken to use Wintergreen in modest amounts, and to keep the oil away from children. One should consider it a bottle of liquid aspirin in this regard.