Plantain (not to be confused with the relative of the banana known by the same name) is a small weed often found in cultivated fields and at the edge of lawns. Traditionally, the crushed leaves were applied to the skin to treat wounds and bites, a leaf tincture was used for coughs, and the dried leaf was taken internally for the treatment of bronchitis, ulcers, epilepsy, and liver problems.

Very weak evidence, too weak to rely upon at all, has been used to indicate that topical plantain is helpful for skin conditions, including poison ivy and eczema.1,2

Similarly weak evidence from two studies performed in Bulgaria hint that oral plantain may be helpful for chronic bronchitis.3,4

Plantain extracts do appear to have anti-inflammatory effects, at least in the test tube.5,6However, unlike most pharmaceutical anti-inflammatory drugs, which work on the cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) systems, one study suggests that plantain may work in a different fashion, by decreasing levels of nitric oxide.5 Whether this indicates any real potential benefit in people remains unknown.

Other possible actions of plantain constituents based on test-tube studies include anti-cancer effects 7and anti-viral actions.8,9

Contrary to some reports, one study found that plantain does not have diuretic (kidney-stimulating) effects.10