The term empathogen is used to describe a class of psychoactive drugs that produce distinctive emotional and social effects similar to those of MDMA ("Ecstasy"). The term was coined in 1983 by Ralph Metzner to denote chemical agents inducing feelings of empathy. In a study of rodents, MDMA was recently shown to induce release of oxytocin, 

The empathy drug MDMA (ecstasy) is thought to increase feelings of love, empathy and connection to others by stimulating oxytocin activity via activation of serotonin 5-HT1A receptors, if initial studies in animals apply to humans.