Can you take ecstasy and still take doxycycline?

It inhibits one of the enzymes (CYP34A) that breaks down MDMA. Thus, you should be cautious (consider taking a 1/2 dose of MDMA) if you are taking doxycycline. Inhibition of CYP3A4 both potentiates the MDMA and is tentatively neuroprotective. it would make the MDMA less toxic as it is the dihydroxy metabolite which is prime for glutathione conjugation and the formation of tertiary and quaternary ultra-toxic metabolites.