Rasa Shastra is the ancient science of Indian alchemy. At present Rasa Shastra is included as a part of Ayurveda pharmaceutical studies in India, since the medicinal properties of mercury including the other metals are being explored for their capabilities on many incurable diseases. Globally a lot of Ayurvedic medicines have been blamed as a risk for health, for containing heavy metals like mercury, lead, arsenic etc. This present work is an attempt to investigate, a traditionally made mercurial medicine called Samirpannaga Rasa, prepared from mercury, sulphur, minerals like arsenic sulphides and oxides following Rasashastra principles. After a 28 day animal trial it was observed that this medicine, following traditional methods of administration was safe to be used in healthy albino rats. This work presents some literary and experimental evidences on safety and efficacy of mercury as medicine. It will change your view about defining a medicine and a poison literally. Ayurveda says that even a poison used cautiously and judiciously for treating a disease is like an elixir of life and even other medicines assumed as elixir, when used injudiciously may lead to death.