After Susano slew the serpent its fangs were made into acupuncture needles as a gift to Amertarasu 

This set of needles can be used to cure any and all poison and all diseases of a target however the process takes 2 days to complete and as they are the fangs of a serpent the poison in them must be neutralized with magic after every use otherwise the patient will die and their body will melt from the poison

protection from poison must be used on them after every use

Notes: Medical Sage