Mecke Reagent Color Chart: How to Read Results

MDMA and MDA both go very dark, near black. Heroin and related opiates turn blue-green. Amphetamine, cocaine, ketamine and LSD do nothing at all. Mecke tells you which chemical family your sample belongs to by the color it turns in the first 45 to 60 seconds, and that is the whole of what it tells you. It cannot separate MDMA from MDA, it cannot measure dose or purity, and no reagent on earth detects fentanyl.

The color chart

Mecke starts clear and gradually darkens in the bottle over weeks or months, which is normal and not spoilage. Read the reaction on white ceramic or hard plastic within the first 45 to 60 seconds. Every reagent eventually drifts to brown or black on its own, so a slow darkening after several minutes is not a result.

Colors follow DanceSafe’s Expected Reactions Color Chart, version 17.

Two entries are worth pausing on. Oxycodone used to carry a single expected color and now spans a range, which DanceSafe widened after real-world results stopped matching the old listing. And 2C-B is left deliberately blank rather than guessed at. That is the right call, and it is the standard to hold any chart to.

Note also that “no reaction” is real information here, not a failed test. Amphetamine, cocaine, ketamine, LSD, mephedrone and PMMA are all documented as no reaction, so a sample that sits there doing nothing is telling you it contains neither a methylenedioxy compound nor an opiate.

Why the color happens

Mecke is selenous acid dissolved in concentrated sulfuric acid. The acid drives a reaction with the target molecule and the structure of that molecule decides the color. The methylenedioxy ring shared by MDMA, MDA and the APB compounds produces the intense dark product. The morphinan skeleton in heroin, morphine and codeine produces the blue-green one. Molecules with nothing for Mecke to grab, ketamine and cocaine among them, give nothing back.

Which is also why Mecke cannot separate molecules that share the key feature. MDMA and MDA both carry the methylenedioxy ring, so both go near-black and look identical in the dish. Only Simon’s reagent tells them apart, and that is why Simon’s is the second bottle in every MDMA workflow. The same logic applies to 5-APB against 5-MAPB.

Running it without wrecking the result

1. Use a tiny sample. A pinhead-sized grain, roughly 10 mg, on clean white ceramic or hard plastic. More sample does not improve the result, it floods the color.
2. One drop, from above. Do not touch the dropper tip to the sample, which contaminates the whole bottle, and do not rest the cap on a dirty surface.
3. Watch the first minute. Note the color at 5, 15, 30 and 60 seconds. Speed matters as much as the final hue.
4. Run a blank. Put a drop of Mecke by itself beside your test so you can see the reagent’s own color for comparison. This is the easiest way to stop yourself calling a non-reaction a reaction.
5. Read under white light against the printed chart. Colored or dim lighting is the most common cause of a misread.
6. Fresh sample for each reagent. Never drip a second reagent onto a spent reaction. Clean up with baking soda, then soap and water.

Where Mecke actually fits

Mecke is not the first bottle you reach for. For something sold as molly or ecstasy, DanceSafe’s current instructions run Marquis, then Simon’s, then Froehde. Mecke earns its place in two situations.

Testing a genuine unknown. Its wide reaction range gives you a fast fork in the road: dark means a methylenedioxy compound, blue-green means an opiate, nothing means neither.

Cross-checking an opioid-shaped sample. Mecke is one of the classic opiate reagents, and blue-green is a distinctive result few other common substances produce.

What it will not do is confirm anything on its own. Reagents flag red flags, not green lights. Read your results across a single row of the chart: if every reagent you ran matches one substance’s row, the result is expected. If any single reagent falls outside that row, the result is unexpected, and the sample goes back to being an unknown.

The mistakes that cause misreads

• Reading too late. All reagents darken over several minutes regardless of what they touched. Judge the first minute.
• Too much sample. A heavy pile reads as uniform black and hides the hue, which matters enormously when the difference you care about is blue-green against black.
• Assuming dark means MDMA. Sugars char to dark brown or black, and so do the APB compounds. Dark is a class signal, not an identity.
• Skipping the blank. Old Mecke is dark in the bottle. Without a blank drop you cannot tell reagent color from reaction color.
• Treating one reagent as the whole answer. Mecke confirms a family, not a molecule, and presumptive color tests carry a real rate of ambiguous results.
• Believing a correct color means safe. The color says nothing about dose, nothing about minor adulterants, and nothing about fentanyl.

What to run alongside it

Marquis goes first: purple to black means a phenethylamine, orange to brown means an amphetamine-type stimulant. Simon’s separates MDMA from MDA, which neither Mecke nor Marquis can do, and MDA vs MDMA explains why that distinction is worth the extra bottle.

Then a fentanyl test strip, every time, because fentanyl can be present when the color looks exactly right. Dissolve the sample in 1 teaspoon (5 mL) of water per 10 mg, or 2 teaspoons (10 mL) for MDMA and methamphetamine, to avoid a false positive, then dip. One line means POSITIVE. Two lines mean NEGATIVE. Full method in our fentanyl test strip guide.

For the complete workflow on ecstasy, see how to test your MDMA; for what each bottle adds to a kit, the test kit comparison.

Color data: DanceSafe Expected Reactions Color Chart, v17 | DanceSafe reagent reaction updates | opiate reference colors per published Mecke reference tables