JWH-210 is an analgesic chemical from the naphthoylindole family, which acts as a potent cannabinoid agonist at both the CB<sub>1</sub> and CB<sub>2</sub> receptors, with K<sub>i</sub> values of 0.46 nM at CB<sub>1</sub> and 0.69 nM at CB<sub>2</sub>. It is one of the most potent 4-substituted naphthoyl derivatives in the naphthoylindole series, having a higher binding affinity (i.e. lower K<sub>i</sub>) at CB<sub>1</sub> than both its 4-methyl and 4-n-propyl homologues JWH-122 (CB<sub>1</sub> K<sub>i</sub> 0.69 nM) and JWH-182 (CB<sub>1</sub> K<sub>i</sub> 0.65 nM) respectively, and than the 4-methoxy compound JWH-081 (CB<sub>1</sub> K<sub>i</sub> 1.2 nM). It was discovered by and named after John W. Huffman.
JWH-210 may be neurotoxic to animals when administered in high doses.
In the United States, all CB<sub>1</sub> receptor agonists of the 3-(1-naphthoyl)indole class such as JWH-210 are Schedule I Controlled Substances.
JWH-210 and JWH-122 were banned in Sweden on 1 October 2010 as hazardous goods harmful to health, after being identified as ingredients in "herbal" synthetic cannabis products. The substances JWH-210, JWH-122 and JWH-203 were classified as illegal drugs by the Swedish government as of 1 September 2011.
As of October 2015 JWH-210 is a controlled substance in China.