Assuming you’ve stopped using the drug and have dealt with the uncomfortable ecstasy withdrawal symptoms, a significant portion of the drug may have cleared from your system. While the effects of ecstasy ingestion typically span between 3 and 5 hours, the elimination half life of ecstasy is said by some sources to be an approximate 7 hours, while others suggest 8 to 9 hours. In any regard, you can expect your “high” to have subsided long before half of the drug has been cleared from your system.
If the reported half life of 7 hours is correct, it can be estimated that it will take a total of 1.60 days for ecstasy to be fully cleared from your system. If a half life of 8 to 9 hours is more accurate, it could take over 2 days for the drug to be completely eliminated from your body. Although most users will have cleared MDMA from their system within 2 days, nearly everyone can expect the drug to have been eliminated within 3 days.
That said, some sources have suggested that urine with high alkalinity can prolong elimination of MDMA, increasing its half life between 16 and 31 hours. Furthermore, the metabolite HMMA (4-hydroxy-3-methoxy-methamphetamine) is thought to remain in the body for nearly 33 hours longer than MDMA. As a result, it could take up to 3 days to fully eliminate the HMMA metabolite from your system.