Enkephalin glycopeptides containing a variety of mono-, di-, and trisaccharides were synthesized and evaluated for their ability to produce analgesia in vivo by simultaneous agonism of both the mu and delta receptor. The lactoside (MMP2200, or Lactomorphin) was manufactured commercially at 400 g scale in a cGMP compliant fashion by PolyPeptide Labs, and by Lonza, which has since sold its peptide manufacturing facility to PPL. It is still being studied, and is used as a laboratory standard. (Polt 2004) [81].