How much does it take to overdose on extasy?

Pure MDMA (ecstasy) overdoses are extremely rare. The LD50 (dose at which 50% of people will die) is 80mg/kg, this means it would be very hard to accidently overdose. It is very important to note that most pills sold as ecstasy do not contain MDMA rather they can contain various amphetamines and research chemicals (i.e mephedrone or MDPV)