... : C5H11NO2S Molecule Weight: 149.21 Manufacture Standards: AJI92,USP26,EP4 L-MethionineIndications and UsageMethionine (abbreviated as Met or M) is an ... a methyl donor. Methionine is an intermediate in the biosynthesis of cysteine, carnitine, taurine, lecithin, phosphatidylcholine, and other phospholipids. Improper conversion ...