S-1 methanandamide is a CB₁ receptor ligand but is less potent than the C-1 (R) methyl isomer. It inhibits electrically evoked contractions in isolated mouse vasa deferentia with an IC₅₀ value of 230 nM. The binding affinity of S-1 methanandamide for CB₁ receptors is less than that of AEA, with a K_i of 175 nM for the displacement of radiolabeled CP 55,940.¹

≥98%