Norsufentanil-d3 contains three deuterium atoms. It is intended for use as an internal standard for the quantification of norsufentanil by GC- or LC-mass spectrometry. Sufentanil is a powerful synthetic opioid analgesic that is used in anesthesia and palliative care. Norsufentanil is a metabolite of sufentanil, produced by oxidative N-dealkylation in the liver by cytochrome P450 isoforms. The physiological and toxicological properties of this compound are unknown. This product is intended for forensic applications.