The Marquis reagent is a chemical used to test Ecstasy pills. The reagent is able to detect MDMA (Ecstacy), 2CB, DXM, DOM, DOB, amphetamine, speed, and methamphetamine. The Marquis Reagent is 9 parts concentrated sulfuric acid (H2SO4) and 1 part formaldehyde (CH2O). Pills are tested by scraping the pill over a white surface (like paper), and administering one drop to the scrapings.

If the chemical turns black/purple, this indicates the presence of MDMA, MDA, MDE, or DXM. If the pill contains DXM, the color change will take 5 seconds or so, MDMA-like substances should change color instantly. The reagent will also react this way in the presence of opiates, which are never used as ecstasy adulterants (this wouldn't be cost efficient). A new testing reagent is now being used to differentiate between MDMA and DXM more clearly; it is called the Mecke reagent (green/black in the presence of MDMA, yellow with DXM, orange/purple for 2C-T-7)

If the chemical turns bright yellow or green, 2CB, DOM, or DOB are present.

If the chemical turns bright orange, amphetamines (speed) are present.

If the pill is PMA, no color change will occur (don't eat it!)

It is important to note that using these pill testing kits (available from do not indicate purity, just presence. DanceSafe runs a legal pill-testing laboratory, that you can safely (and anonymously) mail pills to for analysis (they won't send the pill back, obviously).