Displaying 9 results of Norethindrone Stable Isotopes Norethindrone is a synthetic progestin hormone commonly used in birth control pills. Stable isotopes are non-radioactive isotopes that have a constant atomic weight and do not decay over time. Norethindrone stable isotopes are used in scientific research to trace the metabolism, distribution, and elimination of norethindrone in the body. These isotopes provide insights into the pharmacokinetics and pharmacodynamics of norethindrone and help to improve drug design and efficacy.