How to test THC / CBD?

How to test CBD / THC (cannabis): if you intend to use cannabis (“weed”), first you need a cannabinoid test kit to check it for adulterants. Cannabis products can come in many different forms and can’t be identified by appearence. To test THC or CBD you can use Cannabis reagents in a multiple-use test kit. To detect all ingredients and estimate potency it’s required to use a bigger cannabinoid test kitTo detect fentanyl or test for fentanyl analogs it’s recommended to use fentanyl test strips.

Note: video shows an older, more complicated version of the test kit

CBD / THC reagent test presumptively indicate PRESENCE or QUANTITY, but not PURITY. For best results compare multiple samples at the same time. To detect all cannabinoids and estimate potency it’s required to use a bigger purity test kitA positive or negative test result does not indicate if the substance is safe. No substance is 100% safe.

How to use the cannabis test kit?

  • Test potency of dry or wet cannabis flowers.
  • Test potency of cannabis oils and other extracts.
  • Compare THC potency with old samples: test results don’t fade.
  • Check for presence of THC to help rule out presence of dangerous adulterants.

TL;DR: Here is an image with a quick cheat sheet how to use the CBD / THC Test Kit, or check out more detailed guide on how to test methamphetamine further below.


How can I test THC / CBD (cannabis)?

BEFORE using a CBD / THC reagent test kit

  • It’s RECOMMENDED to use the test under strong light, like daylight.
  • Steps 1-4 are required only for testing amount of THC / CBD, not PRESENCE

(1) STEP ONE for testing THC / CBD flowers / extracts / foods

  • Prepare:
  • Weigh. On a piece of parchment paper weigh 100 mg (uncrushed plant material) or 50 mg (extracts with THC content over 50%)

(2) STEP TWO: heat (decarboxylation)

  • Pre heat an oven to 110 °C. Put the piece of parchment paper with weighted sample onto a middle rack in the oven. Remove after 60 minutes (30 if using a vacuum oven).

(3) STEP THREE: extract

  • Move heated sample from parchment paper to 1 clean Test Vial.
  • Use clean pipette to add 1 ml of the Testing Liquid. Close and shake well. Wait 2 minutes.

(4) STEP FOUR: dilute

  • Take pipette and add 1,5 ml of Testing Liquid into a clean Test Vial.
  • Next with the same pipette add 3 drops of the dissolved sample to the just prepared Test Vial.

(5) STEP FIVE: use reagents

  • Open reagents Cannabis A and B and put caps down so they don’t mix.
  • Pour 1 drop using a Pipette into a new, third Test Vial. Add 5 drops of Cannabis Aimmiedietly followed by 5 drops of Cannabis Reagent B. Close the Test Vial and shake briefly.
  • Check results after 60 minutes. Observe test results from a side, with Test Vial half-standing on a white flat surface.
  • Extracts’ results should be multiplied by 4, e.g. 10% means around 40%.

AFTER using the CBD / THC Test Kit

  • Wash used accessories first with a solvent and next under running water.


  • Cannabis B. It is very important to immiedietly add 5 drops of Cannabis reagent B after adding 5 drops of Cannabis reagent A.
  • No reaction. If your sample does not react, that indicates no presence of THC or CBD, or an error while performing the test. Did you add 5 drops of reagent B immiedietly after 5 drops of A?
  • Color change. Observe results in daylight, from a side, with Test Vials half-standing on flat white surface. Try to compare samples with each other.
  • How many tests can you get from one test kit? The basic CBD / THC test kit comes with enough Testing Liquid and reagents for up to 40 tests. Each one test equals 5 drops of reagents Cannabis A and B each, and 2,5-3 ml of Solvent testing liquid.

How to check if reagent for testing THC / CBD works?

  • Test legal hemp and compare color reactions with instructions.
  • 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 THC / CBD?