JWH 251 is a cannabimimetic indole that shows a high affinity for the central cannabinoid (CB1) receptor with a Ki value of 29 nM. This compound has been identified as an adulterant in herbal blends. JWH 251 3-methylphenyl isomer differs from JWH 251 by having the methyl group at the 3 position, rather than the 2 position, on the phenyl group. The biological and toxicological properties of this compound have not been characterized. This product is intended for forensic purposes.