P21, also known as P021, is a synthetic CNTF?mimetic modified peptide, CAS No:1246751?68?7. The amino?acid sequence is Ac?DGGL(Adamantyl?Gly)?NH?, molecular formula C??H??N?O?, molecular weight 578.66 g/mol. It is supplied as white to off?white lyophilized powder, with HPLC purity ≥98%. This peptide is chemically modified with N?terminal acetylation and C?terminal adamantyl group to improve metabolic stability and blood?brain?barrier permeability for laboratory research applications.