2-Arachidonoylglycerol (2-AG) is a signaling lipid in the central nervous system that is a crucial regulator of neurotransmitter release. 2-AG is an endocannabinoid that activates the cannabinoid CB1 receptor. It binds to both the CB1 and CB2 receptors with similar affinity, acting as a full agonist. It is involved in a wide array of (patho)physiological functions, such as emotion, cognition, energy balance, pain sensation, and neuroinflammation.
2-AG is present at significantly higher concentrations in the brain than anandamide, and there is some controversy over whether 2-AG rather than anandamide is chiefly responsible for endocannabinoid signaling in vivo. In particular, one in vitro study suggests that 2-AG is capable of stimulating higher G-protein activation than anandamide, although the physiological implications of this finding are not yet known.