Literature survey is most essential backbone of the any research work. Critical
review helps in understanding and framing an idea about the subject to be dealt. It deals with
everything right from the past to the present, related to the subject and a clear picture of subject
matter. Hence, for the complete knowledge of the subject, it is necessary to trace out its historical
background, which gives a tangible firm in the development of stages from time to time. Bhasmas
are one of the unique preparations therapeutically used in Ayurveda and have been used as effective
drugs for centuries without any noticeable side effects. Naga bhasma (incinerated powder of Lead)
is one such preparation containing lead as a main ingredient. In present study critical review of
Ayurvedic literature regarding Naga, various methods of Shodhana, jarana, Bhavana, Marana and
various researches carried out on safety issue of Naga bhasma are described in detail. In this study
it is observed that Naga bhasma is mixture of PbO Pb3O4 and contain either OH, (CO3)2 or (SO4)2
and (AsO4)3 group. The research work on acute and chronic toxicity study showed that Naga
bhasma is free from toxic effect. The testicular regenerative potential study elaborates the aphrodisiac
property of Lead. This work helps to know various pharmaceutical process of Naga bhasma, its
chemical nature and safety profile.
Key words: Naga, Bhasma, Lead, Safety, Toxicity.