Displaying 3 results of Methocarbamol Stable Isotopes Methocarbamol is a muscle relaxant used to treat skeletal muscle spasms. Methocarbamol stable isotopes are non-radioactive forms of the drug that have identical chemical and physical properties to the naturally occurring substance. These isotopes are used in scientific research to study the metabolism and pharmacokinetics of methocarbamol, as well as to develop new therapeutic applications for the drug.