2-Arachidonoyl glycerol (2-AG), a natural endocannabinoid ligand for the CB1 receptor, was isolated from porcine brain and characterized. Its congener, 2-linoleoyl glycerol (2-LG), which has a linoleoyl group instead of an arachidonoyl group, also exists alongside 2-AG in vivo. While 2-LG exhibits low intrinsic activity, it enhances the activity of 2-AG and other endocannabinoids through an "entourage" effect, attributed to the inhibition of breakdown and reuptake pathways that typically decrease endocannabinoid levels post-release.