The entactogen and stimulant compound of the phenethylamine class is 4-chlorophenylisobutylamine (4-CAB, AEPCA), also known as 4-chloro-alpha-ethylphenethylamine. It is a para-chloroamphetamine (PCA) analog where an ethyl group has been substituted with the alpha position methyl.
4-CAB is approximately 2 and 5 times less effective in inhibiting the reuptake of serotonin (IC50 = 330 nM) and dopamine (IC50 = 2,343 nM), respectively compared to PCA, and is approximately 3 times less potent in replacing MDMA in animals in drug discrimination assays. Compared to PCA, although its dopaminergic function is greatly attenuated, it is not eliminated, unlike the case of MBDB, and is actually similar to that of MDMA.
4-CAB is also considerably less effective as a serotonergic neurotoxin compared to PCA. As observed 1 week later, a single 10 mg/kg administration of PCA to rats causes an estimated 80 percent drop in serotonin markers. In comparison, 4-CAB doses of 11 mg/kg and 22 mg/kg resulted in decreases of just 20 percent and 50 percent, respectively. Again this is similar to MDMA, which with a single 20 mg/kg dose, induces a 40-60 percent reduction.