Cannabis Potency Test: Measure THC & CBD Levels with the THC/CBD QTest®

A Cannabis Potency Test measures the levels of THC and CBD in your cannabis sample, providing you with crucial information about its strength and effects. The THC/CBD QTest® is an easy-to-use, home testing kit that allows you to measure the THC and CBD content in just minutes. Using a small sample of cannabis, you can quickly determine its potency by following a simple 3-step process: preparation, CBD detection, and THC detection.

To test the potency of your cannabis using the THC/CBD QTest®, you only need a small sample—approximately 0.02g of cannabis flower. This minimal amount allows for accurate testing of both THC and CBD levels, making it an efficient and cost-effective way to measure cannabis potency without wasting material.

Yes! The THC/CBD QTest® accurately measures THC and CBD potency by detecting their concentrations through separate color reactions. This ensures you get reliable, precise results for both THC and CBD levels, helping you understand the cannabis potency in just minutes.

The kit contains everything you need to perform the test, except a precision scale for measuring small amounts of material or liquid drops. We recommend using a digital precision scale for the most accurate results. You can get one in our webshop.

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The answer is yes! The Cannabis potency test can be used for both plant material and extracts to determine the concentration. However, please keep in mind that extracts are more concentrated, so you will need to adjust the amount of starting material accordingly. Our QTests are calibrated for 20 mg of starting material. The color chart is built on this standard. So, to get accurate results, all measurements — solid or liquid — should ideally be normalized to 20 mg.

Please refer to the next Q&A for more details.

Testing Extracts (More Concentrated Samples)

Extracts are significantly more concentrated than plant material. To ensure the test results still fits with the scale from evaluation card, reduce the amount of starting material. After you finish the QTest, multiply the result by the appropriate factor based on the reduced starting material. For example, if you used half the recommended amount (10 mg), double the final reading to determine the actual THC concentration. Here are some recommendations:

• For medium-concentration extracts: Use 10 mg of material and multiply by 2 the end result. The evaluation card will show results ranging from 0% to 50% THC.
• For highly concentrated extracts: Use 5 mg of material and multiply by 4 the end result. The evaluation card will show results ranging from 0% to 100% THC.

Yes! The THC/CBD QTest can be used for liquids and oils. Please follow the instructions below before starting the test.

Testing liquids or oils requires using the enclosed pipette and calculating the weight of the drops for accurate results. Here’s how:

Use the enclosed pipette to test liquid samples. Typically, even high-THC vape products do not exceed 30% THC on average. If you believe the sample is highly concentrated (around 30% THC), we recommend using 1 drop for the test. For samples with lower concentrations, you can use 2–3 drops instead.

The evaluation color scale is calibrated for a 20 mg sample, which shows the corresponding THC percentage. Since you are testing a liquid, you will need a reference weight to calculate the final result. Here’s how to do it:

Measure the weight of your sample drops:

• Fill the pipette with your liquid sample.
• Weigh the vial containing the liquid on a precision scale and note the weight (initial weight).
• Dispense the drops you plan to use for the test back into the vial.
• Weigh the vial again and note the new weight (final weight).

Calculate the drop weight:

• Subtract the final weight from the initial weight to determine the total weight of the drops you used.
• Alternatively, you can measure the weight of multiple drops and divide the total by the number of drops to calculate the weight of a single drop.

Perform the test as described:

• Use the measured drop weight as your reference to calculate the THC concentration.
• Follow the example provided in Section 4: “Evaluating the Result” to calculate the concentration for your liquid sample.

For extracts, depending on the THC concentration, only half (10 mg) or a quarter (5 mg) of the actual sample should be used and then multiply the end result accordingly. But you can also just dilute your sample in some extraction solution and just add a part of it. Check the next questions for example calculations. 

Sample Calculations for Extracts and Liquids

For Extracts:

• 10 mg of extract used: Multiply the result from the color chart by 2.
  Example: If the chart shows 25% THC, the actual THC content is 25% × 2 = 50%.
• 5 mg of extract used: Multiply the result from the color chart by 4.
  Example: If the chart shows 25% THC, the actual THC content is 25% × 4 = 100%.

For Liquids or Oils:

1 drop of oil tested, weighing 20 mg: The result can be read directly from the color chart.
Example: If the chart shows 15% THC, the actual THC content is 15%.

2 drops of oil tested, weighing 50 mg: Adjust the result to account for the weight difference.
Example:

• The color chart shows 20% THC.
• First, calculate the weight ratio: 50 mg ÷ 20 mg = 2.5.
• Then adjust the THC content: 20% ÷ 2.5 = 8% THC in the entire sample.

No, the THC/CBD QTest® is specifically calibrated to measure THC and CBD potency. But we observed sometime a more reddish color reaction with the thc measurement which is probably influenced by other cannabinoids. 

The THC/CBD QTest® is a single-use test designed to provide accurate results for one sample. For additional samples, you’ll need a new test kit.

Store the reagents at room temperature (77 °F / 25 °C) out of direct sunlight for a shelf life of at least 18 months. If possible: it is best to store chemical reagents chilled in the refrigerator.