arristada is injected into the intramuscles as an atypical antipsychotic. in one 12-week clinical trial involving 622 participants, the efficacy of extended aripiprazole was demonstrated. its mechanism of action is not completely known, but is thought to be converted by enzyme-mediated hydrolysis to n-hydroxymethyl aripirazole. the hydroxymethyl aripirazole is then hydrolysed to aripiprazole. efficacy could be mediated through a combination of partial agonist activity d2 and 5-ht1a receptors and antagonist activity at 5-ht2a receptors. since it is a newly approved drug by the fda, many validation of mechanisms of action are still being studied.