Shodhan (Purification) of Visha Dravya: A Critical Review

Visha Dravya, often referred to as poisonous substances, has great value in Ayurveda mainly because of their therapeutic potential if processed properly. The plants which possess various classes of phytochemicals are still found either in their crude forms or after proper processing. Thus, to popularize and introduce their use for medicine, such plant drugs need to be detoxified or purified before use. The process of detoxification or purification of any toxic material used for medicinal purposes is known as "Shodhana". Shodhan, the process of purification, will reduce the toxicity but retain its medicinal properties. This review discusses various classical and contemporary methods employed during Shodhan, Samskara (processing), Bhavana (levigation), and Marana (incineration). It elucidates the scientific rationale behind each step in purification and outlines their pharmacological studies and clinical trials where possible. Additionally, challenges and future perspectives in standardizing Shodhan procedures are addressed to make it reproducible and safe in clinical practice. Overall, this review provides insight into traditional wisdom and modern scientific advancements in the purification of research-oriented Ayurvedists, as well as associated professionals.