What is ephedrine ? Ephedrine and pseudoephedrine are both alkaloids found in the plant Ephedra and are used in medications primarily for their effects on the respiratory system. Despite their similarities, there are several important differences between the two compounds: Ephedrine chemical differences Ephedrine D-isomer and L-isomer chemical differences , % yields . (+)-Ephedrine (hydrochloride) ((+)-EPH, D-Ephedrine, (1S,2R)-(+)-Ephedrine CAS 24221-86-1 Formula: C₁₀H₁₅NO . Molar mass: 165.24 g/mol (1R,2S)-Ephedrine Hydrochloride, presents as a colorless crystalline solid CAS No: 50-98-6, DL-Ephedrine Hydrochloride. Synonyms. (R*,S*)-(+/-)-alpha-[1-(Methylamino)ethyl]benzyl alcohol hydrochloride CAS Number: 134-71-4, (1R,2S)-(-)-EPHEDRINE, 98 CAS ID: 299-42-3,