MDMA (commonly called ecstasy or molly) stays in your system for 1 to 3 days in most standard drug tests, though hair tests can detect it for up to 90 days. The exact window depends on the type of test, the dose taken, and individual differences in how your body processes the drug.
How Your Body Breaks Down MDMA
After you swallow MDMA, your liver gets to work breaking it down. The drug has an average elimination half-life of about 9 hours, meaning half of it is cleared from your blood roughly every 9 hours. It takes about 4 to 5 half-lives for a substance to be essentially gone from your bloodstream, which puts full elimination at roughly 40 to 50 hours for most people.
Your liver also converts MDMA into a secondary compound called MDA, which is pharmacologically active and hangs around longer. MDA has an elimination half-life of about 25 hours, so traces of this byproduct can linger in your body well after the MDMA itself is gone. Drug tests screen for both MDMA and MDA, which is one reason detection windows extend beyond the point where you stop feeling any effects.
Detection Windows by Test Type
Different testing methods look for the drug in different bodily materials, and each has its own detection range.
Urine
Urine testing is the most common method for workplace and legal drug screening. MDMA is typically detectable in urine for 1 to 3 days after use. Federal workplace testing guidelines set the initial screening cutoff at 500 ng/mL, with a confirmatory cutoff of 250 ng/mL for both MDMA and MDA. A heavier dose or repeated use within a short period can push detection toward the longer end of that range.
Blood
Blood tests have the shortest useful window. MDMA is generally detectable in blood for 1 to 2 days after ingestion, though in rare cases it may show up slightly longer. Blood testing is less common for routine screening because the window is narrow and the collection is more invasive.
Oral Fluid (Saliva)
Saliva tests can pick up MDMA within less than an hour of use, making them useful for detecting very recent consumption. The detection window runs up to about 48 hours. Federal oral fluid testing uses a much lower cutoff than urine (50 ng/mL for the initial screen, 25 ng/mL for confirmation), which makes it sensitive even at lower doses.
Hair
Hair follicle testing offers the longest detection window by far. As MDMA circulates in your bloodstream, traces of the drug and its metabolites get embedded into the hair as it grows. Since head hair grows about half an inch per month, a standard 1.5-inch hair sample captures roughly 90 days of drug exposure. Hair testing won’t catch use from the past few days, though, because the drug needs time to grow out from the scalp.
Factors That Change How Long It Stays
The detection windows above are averages. Several individual factors can shorten or extend them.
Liver enzyme genetics. Your body relies heavily on a specific liver enzyme (CYP2D6) to break down MDMA. People carry different genetic versions of this enzyme, and some versions work dramatically less efficiently. One common variant reduces MDMA processing speed by as much as 135-fold compared to the standard version. If you carry a slower variant, the drug clears from your body more gradually, extending the detection window and also increasing the risk of stronger or longer-lasting effects from the same dose.
Dose and frequency. A single moderate dose clears faster than a large dose or repeated dosing over a night. When you take more MDMA before the first dose has been fully processed, both the drug and its metabolites accumulate, giving tests a larger target to detect and pushing clearance times out further.
Body composition and hydration. People with higher body mass, slower metabolisms, or lower hydration levels generally process drugs more slowly. Age also plays a role: liver function tends to decline gradually over the decades, which can extend clearance in older adults compared to younger ones.
Other substances. Certain medications and supplements inhibit the same liver enzyme responsible for MDMA metabolism. Taking these alongside MDMA can slow breakdown significantly, keeping blood levels elevated longer than expected.
Quick Reference: Detection Windows
- Urine: 1 to 3 days
- Blood: 1 to 2 days
- Saliva: up to 48 hours
- Hair: up to 90 days
Why You Might Test Positive After Effects Wear Off
MDMA’s noticeable effects typically last 3 to 6 hours, but the drug remains in your body well beyond that. The MDA metabolite, with its 25-hour half-life, is a key reason. Even after you feel completely back to normal, your body is still processing and excreting remnants of the drug. Urine tests in particular are designed to catch these metabolites, not just the parent compound, which is why a positive result can come back a full day or two after the subjective experience has ended.