Naga Dhatu in Ayurveda: A Literary Odyssey through Rasa Shastra

Rasashaastra, the “Science of Mercury,” is a specialized branch of Ayurveda that deals with herbo-mineral formulations prepared from Rasa Dravyas. Classical procedures such as Shodhana, Jarana and Marana are employed to convert toxic raw materials into safe, potent medicines. Among these, Naga (lead), classified under Putiloha in Dhatu Varga, is described as Tikta, Madhura in Rasa, Atyushna in Veerya, and endowed with Snigdha, Deepana, Rasayana Guna and Lekhana, Medohara, Pramehaghna Karma. It is chiefly indicated in Prameha and related disorders, with additional Rasayana potential. The ideal Naga is characterized by heaviness, easy fusibility, bright black metallic luster, foul odor on melting, and external black color. Before use, Samanya and Vishesh Shodhana are mandatory, followed by Jarana and Marana for safe formulations. In modern science, Naga corresponds to lead, a toxic heavy metal comprising 0.0013% of the earth’s crust. Rasa Shastra principles convert such incompatible forms into therapeutically compatible ones. This paper reviews synonyms, history, and pharmaceutical procedures of Naga described in classical Rasa Grantha.