VIP36 is a synthetic cannabinoid derivative, closely related to the highly potent and neurotoxic designer drug MDMB-FUBINACA. However, unlike MDMB-FUBINACA, VIP36 has a positively charged N-alkoxyguanidine group attached which prevents it from crossing the blood-brain barrier. As a result, VIP36 is a highly peripherally selective drug - neurotoxic effects only became evident at 100x the estimated effective dose needed for analgesia.
See also AZ-11713908 CB-13 MDMB-BINACA MDMB-CHMINACA MDMB-4en-PINACA
References


