Eclipta prostrata, also known as black ink grass, is a very common wild plant. When crushed, the leaves yield a black sap, which is why folk medicine has long associated it with the use of darkening hair.

According to Dr. Ngo Duc Phuong, Director of the Institute of Traditional Medicine, Eclipta alba is commonly used by crushing fresh leaves to extract juice or decocting dried herbs. In some areas, people crush the leaves to extract juice and apply it to their hair and scalp, believing that Eclipta alba helps to darken hair, reduce premature graying, decrease hair loss, and make hair stronger.

According to traditional medicine, Eclipta prostrata has a sweet and sour taste, a cooling nature, and acts on the liver and kidneys. It helps to cool and nourish the blood, and is related to hair. Eclipta prostrata contains wedelolacton, ecliptin, and flavonoids, which have antioxidant, anti-inflammatory, and liver-protective effects. Some experimental studies have shown that this plant can stimulate hair growth and prolong the hair growth phase.