The medicinal value of Plantago seed is seen in its diuretic, vision-improving and phlegm-resolving effects, among others.

Plantago seed is a commonly used traditional Chinese medicinal material. It is the dried, mature seed of Plantago asiatica or Plantago depressa of the family Plantaginaceae, and it is generally harvested in summer and autumn when the seeds are ripe. Its nature and flavour are sweet and slightly cold; in traditional Chinese medicine it is considered to enter the liver, kidney, lung and small intestine meridians. Medicinal material is considered best when the seeds are plump and even in colour, and it is distributed along field edges, roadsides and moist grasslands in most parts of our country.

In terms of medicinal value, Plantago seed is known for clearing heat, promoting urination, draining dampness and treating strangury, and it is often used for difficult urination, edema and painful, dribbling urination. It can also drain dampness and stop diarrhoea, offering some help with diarrhoea caused by summerheat-dampness; in addition, traditional Chinese medicine holds that Plantago seed can improve vision and resolve phlegm, so it also frequently appears in formulas for red, swollen and painful eyes, blurred vision, and phlegm-heat cough.

When used, Plantago seed is mostly taken as a decoction. Because the seeds are tiny and contain mucilage, before decocting they are usually wrapped in gauze, which is what is called wrapped decoction; this both prevents the medicinal liquid from becoming cloudy and reduces irritation to the mouth and throat. In clinical application it is often combined with drugs that promote urination and treat strangury, improve vision or transform phlegm, and the specific combination is decided by the physician according to the condition.

It should be noted that Plantago seed is rather cold in nature, so it is generally not advisable to use much of it in those with deficiency-cold of the spleen and stomach, or with kidney deficiency and seminal emission without damp-heat; pregnant women and people with special constitutions should use it under a physician's guidance. Besides the seeds being used as medicine, the whole plant of Plantago, namely Plantago herb, can likewise be used as a medicinal material, and in some areas the tender leaves are even eaten as a wild vegetable, so it can be said that the entire plant is quite useful.