Dodecylguanidine hydrochloride (CAS No. 13590‑97‑1; formula C₁₃H₃₀ClN₃; MW 263.85 g/mol) is a white to off-white crystalline powder with ≥ 95–98% purity. It dissolves readily in water and alcohol and functions as a cationic surfactant with potent antimicrobial (bactericidal and antifungal) properties.