Reagent kits (Marquis, Mecke, Simon's) reveal common adulterants and confirm whether a sample contains MDMA — they do not report purity or dose. Fentanyl test strips are a separate, mandatory second test given ongoing contamination reports.
For MDMA, use Marquis, Mecke, and Simon's reagents. Test a small shaving of the pill or a grain of powder on a clean white plate. Match the color reaction against the current DanceSafe chart. Then run a fentanyl test strip on a separate dissolved sample. Two tests, always.
Testing is the second layer of the five-layer safety model in our psychedelic harm reduction hub.
Reagent testing is a colorimetric identification test. A small drop of a strong acid or aldehyde solution changes color in the presence of certain drug molecules.3
A reagent test answers: is there something MDMA-like present? Is there something dangerous present that MDMA-like substances rarely mimic? That is it.
Reagent testing has real limits. Treat the results as one input, not as a green light.
DanceSafe's Complete Testing Kit includes the four reagents used in most published harm-reduction protocols.1
| Reagent | What it detects | Expected MDMA color | Red-flag reaction |
|---|---|---|---|
| Marquis | MDMA, MDA, amphetamines, 2C-x | Purple to black | No reaction (yellow/orange) suggests not MDMA |
| Mecke | Opioids, MDMA, 2C-x | Dark blue to green | Brown-yellow with no darkening — likely PMA/PMMA |
| Simon's | Secondary amines — distinguishes MDMA from MDA | Deep blue for MDMA | No reaction — likely MDA, not MDMA |
| Mandelin | Amphetamines, opioids, ketamine | Dark green to blue-black | Bright orange — likely methamphetamine |
No single reagent is enough. Marquis alone can miss PMA (para-methoxy- amphetamine), which has caused deaths sold as ecstasy.4 Marquis + Mecke + Simon's is the minimum for MDMA testing.
A ceramic plate or the inside of a kit box works. Wipe with alcohol first. Bright natural light or a daylight lamp.
Shave the corner of a pill with a clean blade. Take about the size of a grain of rice. For powder, use a small pinch. Split into separate piles — one per reagent.
Hold the bottle vertically. One drop per pile. Do not touch the dropper to the sample — contamination ruins the reagent bottle.
Colors evolve. Record the initial color and the final color. The DanceSafe chart shows both.
Dissolve a small amount of the sample in water per the strip's instructions. This is a mandatory second test.
Reagents degrade over months. A yellowed Marquis bottle is expired and will give unreliable colors.
Fentanyl is the leading cause of overdose death in the United States.5 It has been found in MDMA, cocaine, and pressed pills sold as MDMA or Adderall. Reagent kits do not detect it reliably.
Fentanyl test strips are immunoassay strips. A small sample dissolved in water is dipped for 15 seconds. Two lines mean negative. One line means positive. A negative test lowers risk but does not eliminate it — fentanyl distributes unevenly in a mixed sample ("hot spots").
Always test more than one part of the sample. Have naloxone (Narcan) available if there is any chance of opioid contamination. Naloxone is over-the-counter in every US state as of 2023.
Read the color under bright, neutral light. Compare against the current DanceSafe color chart, which is updated when new adulterants appear.1 Do not rely on memory or on old printed charts — the chart is a living document.
Any of these findings is a hard stop:
DanceSafe.org is the primary US retailer. They ship the reagents themselves and the color charts. The Loop is the UK counterpart with on-site drug-checking at festivals; useful for reference if you are in Europe.
Fentanyl test strips are sold by DanceSafe, Bunk Police, and many state and county health departments (often free). Check your local health department first — some ship them at no cost.
Reagent kits and fentanyl test strips are federally legal. Every US state has now removed drug-checking equipment from its paraphernalia list, most recently between 2021 and 2024. Ownership of the kit is not a crime.
Possession of MDMA is illegal under federal law and in every state. Testing does not change that. Testing does mean that if something goes wrong, you and the person you are with have more information when calling 911.
For interaction risk with other medications, see our psychedelic medication safety guide. Full safety framework in the harm reduction hub. For difficult experiences during MDMA sessions, see the bad trip recovery guide.
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