Norchlorcyclizine, (-)

The specific (-)-Norchlorcyclizine (or S-enantiomer) is the focus in some studies, distinguishing it from the racemic mixture. Norchlorcyclizine, especially its (-)-enantiomer, is a metabolite of the antihistamine Chlorcyclizine, known for its antihistaminic, antiemetic (anti-nausea), and anticholinergic effects, used in allergy relief and motion sickness, but also studied for its role in teratogenicity (causing cleft palate in rats) by affecting GAGs, and serving as a precursor in synthesizing other APIs like Cetirizine.