Displaying 3 results of Nalmefene Stable Isotopes Nalmefene stable isotopes are isotopes of the drug nalmefene that are chemically identical to the regular drug but contain non-radioactive isotopes. These stable isotopes are commonly used in clinical trials and research to identify the drug's metabolic pathways and to monitor its path through the body. They are safe to handle and do not pose health risks to researchers or patients.