[CAS Number 1197-21-3] Synonym: a,a-Dimethylphenethylamine.hydrochloride. Phentermine.HCl is a stimulant and appetite suppressant used in the short-term treatment of obesity. This sympathomimetic amine was a component of the recalled anti-obesity medication fen-phen. Phentermine.HCl is available as reference material (bulk powder and/or solution) and as calibrated, Ready-to-Use, certified reference material (CRM). This product is designed for qualitative and quantitative protocols and can be used for forensic, toxicology, research, and other chemical/biochemical analytical applications.