4-Chloro-α-pyrrolidinovalerophenone (commonly abbreviated as 4-Cl-PVP) is a synthetic cathinone belonging to the broader class of substituted pyrrolidinophenone compounds. Synthetic cathinones are a group of novel psychoactive substances (NPS) that have been studied extensively in analytical chemistry, forensic toxicology, and public health surveillance due to their changing chemical structures and appearance in drug monitoring programs.