Homeopathic practitioners use it for runny nose, hay fever, and sore throat.
Its effectiveness for these problems has not, however, been scientifically verified. Why It Works Black Mustard's medicinal effects stem from a potent oil released when the powdered seeds are mixed with warm water. Mustard has been in use for well over 2,000 years. The Romans ate mustard pounded and steeped in new wine. Later, the Saxons are believed to have used it as a condiment.