TABLE 2.3 Comparison of Cannabinoid Receptor Agonists

Potency can be measured in a variety of ways, from behavioral to physiological to cellular. This table shows potency in terms of receptor binding, which is the most broadly applicable to the many possible actions of cannabinoids. For example, anandamide binds to the cannabinoid receptor only about half as avidly as does THC. Measures of potency might include effects on activity (behavior) or hypothermia (physiologic).      The apparently low potency of 2-AG may, however, be misleading. A study published late in 1998 reports that 2-AG is found with two other closely related compounds that by themselves are biologically inactive; but in the presence of those two compounds, 2-AG is only three times less active than THC.9 Further, 2-AG is much more abundant than anandamide, although the biological significance of this remains to be determined.

Receptor Binding in Brain Tissue124
Compound	Potency Relative to 9-THC
CP 55,940	59
9-THC	1
Anandamide	0.47
2-AG	0.08