Andrographis paniculata is an ancient medicinal herb with an extensive ethnobotanical history in Asia. It is found through Chinese medicinal literature, modern and ancient; it is prominently listed in the Indian Pharmacopoeia. A member of the Acanthaceae plant family, it is also widely used in Scandinavian countries to treat and even prevent common colds.

In traditional Chinese herbalism, Andrographis is used to support healthy digestive, cardiovascular and urinary systems. In Sweden, Andrographis has been used for more than 10 years as a primary herb for the winter season.

Long known in traditional Asian medicine as an immune system booster, Andrographis has demonstrated significant activity in fighting common cold, flu, and upper respiratory infections.

According to studies in China, andrographis is effective in preventing the formation of blood clots and preventing the re-clogging of arteries after angioplasty - a technique used to treat blocked arteries by inserting a balloon into the blood vessels which is then inflated to widen the artery.

Further research shows that the herb activates fibrinolysis, a natural process in the body in which blood clots are dissolved. It also relaxes the smooth muscle in the walls of blood vessels and has a blood pressure-lowering effect.

The herb's anti-viral activity has been demonstrated in HIV and AIDS. Andrographis prevents the virus from infecting healthy T-cells and inhibits the spread of infection, while other studies show that the herb is able to fight HIV in cells even after they have been infected.

Scientists have found that andrographis hinders HIV from taking over a 'control enzyme' in certain T-cells that triggers the multiplication of the virus. This action is the same as AZT, a commonly used AIDS drug with a number of debilitating side-effects, including a low blood count.

Finally, andrographis extracts are showing promise in relieving diarrhoea associated with E.coli bacterial infections.

In one study, andrographis was given to 1,611 people with bacterial dysentery and 955 people with diarrhoea. The results showed an overall effectiveness of 91.3 per cent.

The suggested dosage for andrographis is 400mg twice a day (for up to 10 days). Although andrographis has been found to be safe in humans, animal studies suggest it may impair fertility. Safety in young children and pregnant or nursing women has not yet been established.