An HPLC method was developed and validated for Related compounds test to replace both the Ordinary Impurities and the Limit of norethindrone TLC methods in current USP Norethynodrel monograph (USP 30, 2077). The HPLC method was developed based on the chromatographic conditions in USP Norethindrone and Ethinyl Estradiol Tablets Assay (USP 30, 2773). It completely separated norethynodrel from norethindrone and ethinyl estradiol. The resolution between norethynodrel and norethindrone peaks was 7. The tailing factor was 1.1 for norethynodrel and 1.2 for norethindrone. The relative standard deviation of the peak area response of standard solution for norethinodrel and norethindrone was less than 1.0 %. The detection limit of norethynodrone was 0.1% of the test solution. On USP Norethynodrel RS and a commercial norethynodrel sample, the HPLC method detected three more impurities than the current Ordinary Impurities TLC method. USP Norethynodrel RS exhibited less than 2.0% of total impurities, including norethindrone, while the commercial norethynodrel sample exhibited more than 2% of total impurities.