Introduction : Andrographis paniculata is traditionally known as kalmegh. The plant belongs to family Acanthaceae and is widely used in Ayurvedic and Homeopathic systems of medicine. The plant grows in waste grounds and prefers moist habitat. The herb is bitter in taste and has weak odor. The whole plant may be used in medicine.

History : Peoples and students in India are using Kalmegh extract for studies since a long time. As per Ayurvedic research, Kalmegh extract can reduce the severity of cold symptoms.

Chemicals : Chemically the drug contains flavones and lactones. Among lactones Andrographolide is the main constituent and it also active principle of the plant. The herb also contains minerals and is a rich source of sodium chloride. Andrographis paniculata has been standardized to contain 10% of Andrographolide as Kalmeg extract. Andrographis does not contain and has nothing to do with "androgens" (testosterone) or any steroids. The active components of andrographis are "andrographolides", very bitter compounds known as diterpene lactones found in the aerial parts of the plant (leaves and stems). The andrographolide content of the leaves varies considerably from season to season, such that standardized extracts are much more reliable as means of supplementation than the leaves or the whole plant.