How to test 2C-B?
How to test 2C-B: if you intend to use 2C-B, first you need a 2C-B test kit to check it for adulterants. Pure 2C-B usually looks brown, but can’t be identified by appearence. To test 2C-B use reagent tests Marquis, Mecke, Robadope and Simon’s in single-use or multiple-use test kits. To detect fentanyl or test for fentanyl analogs it’s recommended to use fentanyl test strips.
Drug tests presumptively indicate PRESENCE, but not PURITY or QUANTITY. Use different tests to improve accuracy and to detect adulterants – 90% of adulterants will react with 1 out of 3 reagents, and 95% with 1 out of 5.
A positive or negative test result does not indicate if the substance is safe. No substance is 100% safe.
TL;DR: Here is an image with a quick cheat sheet how to use the 2C-B test kit, or check out more detailed guide on how to test 2C-B further below.

What test kit do I need to test 2C-B (Nexus)?
SAMPLE | RECOMMENDED TEST KITS |
2C-B | primary test – Marquis secondary test – Mecke secondary test – Robadope recommended test kits: – single-use MDMA test kit – multiple-use MDMA test kit |
How can I test 2C-B?
BEFORE using a 2C-B test kit
- It’s RECOMMENDED to record the reaction to compare later
STEP ONE for testing 2C-B pills / capsules / powder
- Take and finely crush a small piece, no bigger than a head of a needle – like this •.
- Put it on a suitable testing plate, preferably a spot test plate or the bottom/underside of a ceramic mug (example). *If using single-use vials insert the sample and observe, as the reagent is already within.
- Add one (or two) drops of Marquis reagent test (or other supplied) on the sample and wait for the results.
- Check reagent test results with instructions.

How to use a 2C-B test kit?
- Check test results with Marquis test kit: if testing 2C-x (2C-B/C/H/I) the color of the reaction should be yellow turning green.
- To tell apart 2C-B and other 2C-x compounds use Mecke test kit, which turns orange with 2C-B.
STEP TWO testing 2C-B for adulterants
- To detect 2C-B adulterants you can use tests Simon’s (for MDMA, meth, mephedrone, methylone or PMMA) and Zimmermann (for a-PVP and 4-MMC derivatives). They react to secondary amines and secondary and tertiary cathinones, but not to 2C-B.

AFTER using a 2C-B test kit
- OPTIONAL: Pour baking soda over a finished reaction to neutralize used reagents.
- Wash testing surface under running water.
FAQ
- Fizzing. Any synthetic drug in a form of salt will bubble with most reagent tests, which are strong acids. If you see only fizzing instead of color change, that can indicate presence of a new psychoactive substance.
- Speed of the reaction does not indicate quantity nor purity. However, if you are having trouble interpreting your result try using a bigger sample or crushing it better before testing.
- How many tests can you get from one test kit? A multiple-use test kit lasts up to 100 (5 ml) or 200 (10 ml) tests. Each drop equals one test. A single use-test kit contains 2 disposable ampoules (2 tests).
All 2C-B test results:
TEST | 2C-B |
MARQUIS | Yellow > Green |
MECKE | Yellow > Orange |
MANDELIN | Green |
LIEBERMANN | Yellow > Black |
FROEHDE | Yellow > Green |
EHRLICH | No color change |
HOFMANN | No color change |
SIMON’S | No blue color change |
ROBADOPE | Slow pink |
SCOTT | No full color change |
ZIMMERMANN |
2C-B test did not react as indicated? Watch out!
All test results are available in our instructions and TestDrugs apps.
How to check if reagent for testing 2C-B works?
- Test any substance and compare color reactions with instructions. It’s easiest to use aspirin – Marquis reagent reacts to it with a slow pink or orange color change.
- Keep a sample to compare later in case of doubt. If control sample reacts fine, it means the reagent still works.
Looking where to buy a kit for testing 2C-B?
- Single-use 2C-B test kit – 3,9 EUR per test, FREE SHIPPING
- Multiple-use 2C-B test kit – just cents per test, set of 4 reagents
- Fentanyl test strips – learn how to test 2C-B for fentanyl
- …or check out the guide “What is the best reagent test?” and choose from all available SIN reagent test kits
How to detect fentanyl?
BEFORE using a fentanyl test strip
- It’s RECOMMENDED to test each and every dose. Because of extreme potency (microgram range) fentanyl is never evenly mixed in.
STEP ONE for testing fentanyl powder / pills / spice
- Dissolve 100-200 mg in at least 125 ml of water (half a cup).
- Grab a test strip by blue end and insert it into the liquid, no higher than the blue line.
- Wait until liquid starts visibly moving up the test strip (up to 15 seconds).
- Put the test strip away on a flat dry surface and read the result in 2 minutes.
How to use a fentanyl test strip?
- Check test strip results: a single line confirms the presence of fentanyl, while two lines (even faint) rule it out.

Fentanyl test did not react as indicated? Watch out!
All test results are available in our instructions and TestDrugs apps.
FAQ
- Faint line. Even faint second line result is enough to rule out the presence of fentanyl.
- Injecting. If you inject you especially need to test each and every dose. It’s best to test the spoon (or cooker) residue every time before use.
- Speed of the reaction does not indicate quantity nor purity. However, if you are having trouble interpreting your result try using a bigger sample or crushing it better before testing.
- How many tests can you get from one test kit? A single fentanyl test strip is enough for one test.
Looking where to buy a test kit for fentanyl?
- Reagent test kits – just cents per test, good for pure fentanyl
- Fentanyl test strips – tests for fentanyl and fentanyl analogs
- …or check out the guide “What is the best reagent test?” and choose from all available SIN reagent test kits
List of all SIN guides how to test drugs:
How to test 2C-B?
How to test MDA?
How to test MDMA?
How to test LSD?
How to test DMT?
How to test THC & CBD?
How to test FENTANTYL?
How to test COCAINE?
How to test MESCALINE?
How to test KETAMINE?
How to test MEPHEDRONE?
How to test AMPHETAMINE?
How to test METHAMPHETAMINE?
How to test HEROIN & OPIOIDS?
How to test an UNKOWN substance or RCs?
and how to detect cuts or other adulterants:
How to detect LEVAMISOLE?
How to detect PMA/PMMA?
How to detect FENTANYL?
How to detect NBOMes?
HARM REDUCTION
A positive or negative reaction does not indicate if the substance is safe. Learn more at erowid.org.