How to test FENTANILS?

How to test fentanyl: if you intend to use an opioid, first you need to check it using a test kit to rule out presence of dangerous adulterants such as fentanyl. Fentanyl can be even 100 times more potent than morphine, and therefore is easy to accidentaly overdose on. Fentanyl can be mixed in any kind of sample and can’t be identified by appearance. To detect fentanyl or analogs it’s recommended to use fentanyl test strips.

How to use fentanyl test strips? [BASICS]

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.

Why use fentanyl testing strips? Lethal dose of fentanyl can be invisible to naked eye and can’t be identified by appearence.

What test do I need to test fentanyl?

Pure fentanylprimary test – Fent Strips
primary test – Marquis
secondary test – Mecke
secondary test – Liebermann
secondary test – Froehde
primary test – Fent Strips

How can I test 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.
Test Strip for testing Fentanyl
How to test fentanyl? Fent strips instructions.

Fentanyl test did not react as indicated? Watch out!
All test results are available in our instructions and TestDrugs apps.


  • 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 testing kit for fentanyl?

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 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?


A positive or negative test result does not indicate if the substance is safe. Learn more at