How long will mdma stay in my system for?

6-9 hour half life: Mdma has a short half life (6-9 hours) relative to some other drugs (e.g., marijuana) but the amount you used, how long use was sustained, amount stored in your body fat and health/metabolism factors will determine how long it will be in your system. By 1-3 days later it is typically not found by urine tests but detectable in hair analysis for up to 90 days.