Prabhava in Ayurveda is the potency of a drug. It is a conceptual part of Ayurvedic pharmacology and is discussed elaborately in Ayurvedic classes. Generally, a drug is supposed to act in a particular manner owing to its possession of what are called rasa (essence), guna (property), virya (energetic principle) and vipaka (altered state of drug). Actions are attributed corresponding to each one of these factors. If a given drug acts in a more efficient manner without any regard to the factors cited above and does not correspond to, and cannot be attributed to, the presence of either f the four named above, then a concept like prabhava become necessary to explain the cause of action. Agnivesha, in his medical compendium, defines prabhava as the distinctive feature responsible for some specific effects not supported by taste, vipaka ad potency possessed by two drugs similar to each other. Superseding the nature of a drug, prabhava acts in a specific manner. For example, if two drugs are