Pharmacodynamics in Ayurveda encompass the examination of how various substances, including herbs, minerals, and other natural compounds, interact with the human body to yield therapeutic effects.Ayurveda adopts its own function-oriented approach through its alternative theories of Panchamahabhuta, Tridosha, Saptadhatu, Agni, Ojas and Srotas which cannot be fully explained in terms of scientific parameters of present era. Hence, to cope up these lacunae up to some extents, a critical literary and conceptual study of Rasapanchaka ie, Rasa, Guna, Veerya, Vipaka and Prabhava are done.Ayurveda uses Panchamahabhuta theory as the fundamental basis of drug action. Dravyas are of three categories, some alleviate doshas, some vitiate dhatus, and some are good for the maintenance of positive health. Apparently, it also means that the drugs have potentialities to prevent the diseases.Drug action in ayurveda is explained in terms of Actions or effects of drugs (yatkurvanti tat karma), Potency of drugs (yen kurvanti tat veeryam), Site of action (yatra kurvanti tat adhikaranam), Time of administration of drugs and the period of their optimum concentration in the blood or the organ (yada kurvantisakalah), Mode of action (yathakurvantisaupayah), Specific therapeutic action (yukurvanti tat karma). Ayurveda advocates that drug should be used as a whole as Agni which is responsible for the health as well as disease, also to improve the condition of agni at all level. Ayurveda medicines can be used for long term treatment as bacteria are unable to develop resistance against these drugs. The effective of the drug may be wholesome or unwholesome, but the reason behind is the potency of the drug.

Keywords: Ayurveda pharmacodynamics, Critical analysis, Rasapanchaka.