Catnip, also known as catmint, catswort, and field balm, is a member of the mint family of herbs and is believed to have originated in regions of Europe. Today catnip can be found growing in most of the milder climates of the Northern Hemisphere. Catnip plants have fuzzy, grayish-green leaves and small, white flowers that bloom in the summer. The flowers, leaves, and stem are cut while the plants are in full flower and then dried for use in herbal preparations. Because it repels certain insects, catnip or chemicals derived from it have been used in pesticides.
Taken orally, catnip is most commonly used in connection with anxiety, insomnia, and nervousness. It contains a substance, known as nepetalactone, which has a sedative effect in humans. (Nepetalactone is very similar to valepotriate found in valerian a more commonly used herbal sedative.) Due to this effect, catnip may also be used to help lessen migraine headaches. Catnip has also been used historically to relieve stomach complaints such as colic, cramps, gas, and indigestion because chemicals in it may have muscle-relaxing, or antispasmodic, effects.
Topically, catnip has often been used to reduce swelling associated with arthritis, hemorrhoids, and soft tissue injuries.