For now, says Silva, there is scarce evidence that existing synthetic cannabinoids are medicinally useful: As most of the drug candidates worked their way up the pipeline, adverse effects have tended to crop up. Because of that, says Silva, most pharmaceutical efforts to develop synthetic cannabinoids have been discontinued.
But that doesn’t mean all research has stopped; a synthetic cannabinoid called JWH-133, for example, is being investigated in rodents for its potential to reduce the size of breast cancer tumors. It’s possible to make tens of thousands of different chemical modifications to cannabinoids, and so, says Silva, “it is likely that some of these combinations may have therapeutic potential.”