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Ecstasy Testing Kit FAQ
Marquis Reagent
by Erowid

v 1.27, Feb 2023



Ecstasy pill testing kits are relatively simple, inexpensive products which allows people to test unknown pills to help determine their contents. Because the quality of street ecstasy is notoriously poor, having the ability to at least narrow down the possible contents can help reduce the risks associated with the use of street ecstasy.

The ecstasy testing kits contain a combination of chemicals called a 'Marquis Reagant'. A '"reagent" in this case means a chemical or combination of chemicals which, because of the reaction they cause, can be used in the testing or analyses of other chemicals. The primary use of the marquis reagent in the United States is by law enforcement as a field test for the presence of amphetamine and opiates. It's only within the past three years that they have started to be marketed to the public as a harm reduction tool.

Who sells kits? (where to buy)

Testing kits are available from a number of organizations. There have been reports of customs seizing testing kits and therefore people often try to order from within their own country or continent. In 2015, a friend of Erowid report that a testing kit was seized and they were contacted by customs authorities to ask why they wanted an illegal drug-related product.

How do the Kits Work?

Ecstacy testing kits come in the form of a bottle of liquid. The test works by scraping a small quantity of powder off the side of a pill and onto a plate. The scraping can be done with anything, but some people find that a fingernail file or razorblade works well. A small drop of the testing kit liquid is then dripped onto the powder scrapings.

A chemical reaction will happen between the liquid reagent and some of the more common chemicals found in ecstasy pills. This reaction may cause the liquid to turn a variety of colors depending on what is in the powder. This color change generally happens within a period of 10-15 seconds after combining the powder and liquid.

What is the chemical in the kits?

The Marquis Reagent is 9 parts concentrated sulfuric acid (H2SO4) and 1 part formaldehyde (CH2O). Some vendors add methanol to the mixture in an attempt to slow the speed of the reaction for easier viewing.

What do the kits tell me?

The kit can identify whether a substance does not contain the presence of ecstasy-like substances (MDMA, MDA, MDE) through lack of reaction. The test kits can not positively identify that a pill contains ecstasy. It can not differentiate between the MD* chemicals nor tell you how much of these are in a pill. There is a growing belief that 'bunk' ecstasy producers are including a small amount of Marquis-positive chemicals to 'fool' the tests.

The Marquis test will turn dark purple/black for several substances (not just ecstasy-like compounds) therefore the presence of purple/black reaction does not mean the pill necessarily contains ecstasy. Marquis field tests have been traditionally used to detect the presence of opiates & heroin (which turn pink to purple).

Full instructions, including color charts, come with the kits, but here is a general description of the most common results :

No color change
If there is no color change, the pill does not contain noticeable quantities of MDMA (ecstasy), MDE, MDA, 2C-B, DOM, DOB, DXM, methamphetamine, or amphetamine.
Dark Purple / Black
Black or very dark purple/blue most often indicates either the presence of an ecstasy like substance (MDMA, MDE, or MDA), DXM, or opiates. It is possible to differentiate between DXM and the ecstasy like substances based on the period of time it takes for the reagent to turn black.
Dark Grey
DXM will emit a small amount of smoke first, then turn the reagent black after 5-10 seconds. Ecstasy-like substances may emit a tiny bit of smoke (generally not as much as DXM) and will begin turning color immediately.
Bright Yellow / Green
Indicates the presence of 2C-B, DOM, or DOB.
Bright Orange
Indicates the presence of Speed, Methamphetamine, or Amphetamine.
Other Colors
If the reagent turns some other color, it is an indication that the pill does not contain ecstasy, or any of the above substances, but DOES contain some other unknown, possibly dangerous chemical. See below.

There are chemicals which do not cause a reaction with the ecstasy testing kits. Just because a pill tests positive for an ecstasy-like substance does not mean that the pills are pure or safe. They may contain a wide variety of other safe or dangerous chemicals.

Following is a chart showing preliminary results submitted to us for how the Marquis Reagant reacts with a variety of other chemicals.


2-AminoIndanOrange to Red (slightly rusty)
25I-NBOMe (freebase, uncomplexed)Brown to Dark Lime Green (erowid + ecstasydata confirmed)
2C-CStarting brown going to Dark Lime Green (similar to 2C-B)
2C-DVery light pink
2C-ENo reaction (!?)
2C-IDark Green to Black
2C-T-2Orange to Red (usually a sort of salmon color)
2C-T-4Orange to Red (usually a sort of salmon color)
2C-T-7Orange to Red (salmon, again; also, there is less tendency towards orange than 2C-T-2 shows)
4-Acetoxy-DiPTDirty (blackish) olive
4-Methyl-Aminorex (u4euh)no color change
4-MTAno color change
5-MeO-DiPTFizzes then turns yellow quickly changing to a slightly rusty orange
Alpha-Methyl-DiPTFizzes then turns brown
AMTDark brownish-yellow
BDBDark brown, nearly black
BenzylpiperazineNo color change, but it causes the reagent to fizz. Looks like when you pour hydrogen peroxide on a cut.
DiPTFizzes strongly then turns a neon yellow
DPTDirty olive
HarmineFizzes slightly, much less so than BZP, and turns a brown-orange rust color.
IAPImmediate reaction to salmon/red, slowly intensifies to a darker red over 1min.
LSDComplicated: Color change not reliable with liquid, blotter, or tablet LSD because doses are too low See Marquis and LSD: Is color change visible?
MBDBDark Brown to Black
OpiatesPink to Purple
PMANo color change
Table Salt (Sodium Chloride)Tends to foam, no color change (Marquis Reagent Reaction)
SugarSlow from yellow to dark brown (Marquis Reagent Reaction)
TMA-2Lime Green (similar to 2C-B)
TMA-6Yellow to Orange
YohimbineFizzes slightly, much less so than BZP. Slowly (up to a minute), it will turn an olive green color.


2C-E light yellow/green within 10 seconds
2C-I Immediate reaction to a reddish brown similar to drying blood
2C-T-21 Dark blood red which turns to an imperial purple over 30 seconds
4-Methyl-Aminorex (u4euh)no color change
IAPNo Reaction
TMA-6Dirty olive, gradually develops orange on the edges of the liquid puddle after about a minute


2C-ENo reaction
2C-INo reaction
2C-T-21Greenish blue
IAPNo Reaction

Are the kits dangerous?

The primary ingredient in the Marquis testing kits is sulphuric acid (H2SO4). This is an acid which will burn skin if it comes in contact. The kits need to be handled very carefully. They should be stored in a glass container with a tightly sealing lid, and preferably the glass container would then be placed in another external container to contain any leakage or spills if the bottle were to break.

Once the test is performed, the resulting reagent/powder mix should be carefully washed off the plate without coming into contact with skin. If a spill occurs, diluting with water is the safest option, and baking soda can be used to clean up in carpet, however be careful because acid+base results in heat (an 'exothermic' reaction) and if one spills a whole bottle, it could be dangerously hot to attempt to neutralize with baking soda. If the reagent comes into contact with eyes or skin, rinse thoroughly with water for at least 2 minutes and see a doctor if irritation continues.

Formaldehyde (the secondary ingredient) is a known carcinogen in humans which has been linked to nasal and lung cancer and with possible links to brain cancer and lukemia. Formaldehyde exposure can irritate the eyes and mucus membranes if vapors come into contact with the eyes. For more information, see Osha's page on formaldehyde.

Are the kits legal?

There is some question as to the legal status of testing kits in the U.S. Many states include wording in their paraphernalia laws which include anything which "identify, analyze, or test" scheduled substances. This wording _is not_ included in the federal paraphernalia laws. Arguably, the ecstasy testing kits do not fit within this category as they only verifiably test for the _absence_ of MDMA or other controlled substances. (i.e. if a sample does not turn a color, we can be reasonably sure that there is no MDMA present, however if the sample turns black it could mean that mdma is present or it could indicate the presence of another completely unrelated substance).

These kits have been widely available for over a year and we have heard of no legal problems either with their sale or possession. We know this isn't a very satisfactory answer, but the U.S. legal system is often confusing on points like this. As a general rule, if people aren't being prosecuted for it, it's unlikely that _you_ will be.

Because it's not federally illegal, importation should not cause any legal problems, but many people choose to avoid having to deal with customs by order from a vedor on their own continent. We do not currently have any information about the legality of testing kits in countries other than the United States.

How long is a kit good for?

Testing kits will eventually go bad. At this point we've heard that they can go bad in as little as six months, though some people have had them stay useful for years when they are stored cold and air-tight. Keeping the testing kit reagent in a well-sealing dark glass bottle, cool or refrigerated may help extend its life.


This FAQ was written by with technical consultation by Murple.

Related Links

Revision History

  • Feb 2023: Revised list of reagent vendors
  • Dec 2003: Added marquis reactions for (2ce & iap) and a couple mecke and simons reactions. Thanks to NaFun.
  • July 2003: Added more marquis reactions (2ct4, 2ci, 2ai, tma2, 2cc, MBDB)
  • First Draft 1999