When a medicine has beneficial effect of curing a particular disease, it may also have some side effects. Study of toxicity in herbal medicine is carried out in order to find out whether it will affect any other human organ or produce any bad side effect both short and long term. In the study of toxicity, one attempts to understand whether it is acute toxicity, chronic toxicity, muta-genicity, carcino-genicity or terroto-genicity for the medicine under test. Herbal medicine which has been used by generations, many of the toxicological effects are likely to be absent. Defence lab in Gwalior, has built up excellent expertise in carrying out toxicology studies for all medicines including herbal medicine.