THC % Testing and Accuracy Errors

Weed TiedWe know, you walk into a dispensary and find flower labeled up into the 30% THC level. You think, why would I buy anything lower? I am paying for the THC, I want the most possible. Well you might not be getting what you think.


The Journal of the American Medical Association recently published findings that only 17% of cannabis products were accurately labeled for content in San Francisco, Los Angeles, and Seattle. The study randomly selected 75 products from 47 different brands and independent testing found that 17% were labeled accurately, 23% were under labeled, and 60% were over labeled with respect to THC content. Even though the testing of cannabinoid content is being required by more and more states, without a standard method to regulate labs, results will always be varied from lab to lab. State-approved laboratories are producing different results, which invalidates the legitimacy of testing altogether.

Different methods of testing also effect the outcome of testing results. Gas chromatography involves vaporizing the sample and testing the vapor. High Performance Liquid Chromatography liquefies the sample and tests the sample, giving a more accurate result. So many factors go into THC testing methods that mistakes are prevalent and regulation is non existent.

The fact that lab tests are very expensive means that only a few small samples of each product get tested. This can lead to issues with homogeneity, meaning that different parts of a cannabis batch can yield varying potency. The result is typically that producers submit the most potent parts of the batch to be tested, and the laboratories end up averaging these inflated results. This process of testing from a biased selection may be an answer to why the JAMA study found such a high percentage of mislabeled cannabis items.

There is  no regulation in how samples are chosen. What growers send to labs may not represent the harvest. A grower harvesting a crop of 25 plants can select for testing the best-looking bud encased in THC-loaded crystals, rather than a brown one that looks like a hairball. Concern has arisen of samples being rolled in kief or extract dripped on it before being sent for testing. Groups of secret shoppers are being considered to purchase samples from dispensaries to apply independent testing. A fundamental conflict also resides at the heart of the testing industry. Producers pay labs for their tests. If producers don’t like the results, they could take their business elsewhere. Efforts are being taken to insure that financial incentive is not influencing test results.

Until regulation for testing is passed the results from such tests should always be questioned. THC levels above 28% are rare and levels above 27% usually require a retest in most labs. THC is also only one of an array of Cannabinoids that make up the effect and euphoria of your flower. Don’t be taken in by artificial numbers claiming a better product.Those lab tests are not indications of personal preference. Research and testing strains to find the terpene profile that best effects you is the greatest way to find the medicine that is right for you.



What are your thoughts?