Your Weed Might Not Be As Strong as the Label Says, Scientists Find

Many legal cannabis consumers rely heavily on the THC percentage printed on product labels when deciding what to buy. But new research indicates that these labels may not be telling the full truth. A recent study has revealed that nearly half of cannabis flower products sold in the legal market are inaccurately labeled, with most overstating their actual THC potency.

Researchers carried out a wide-ranging audit of cannabis flower from dispensaries in a legal state and found a major discrepancy between advertised potency and lab-verified results. According to the study, about 44 percent of tested flower products failed to meet the state’s accuracy standard, which allows for a 15 percent margin of error. In most of these cases, THC content was inflated. While some inaccuracies were relatively small, others were striking — one product listed at 24 percent THC was found to contain only 16 percent.

Interestingly, cannabis concentrates such as oils and waxes did not show the same level of inconsistency. Ninety-six percent of concentrates matched their listed THC content. Researchers attribute this difference to their uniform composition, which makes them easier and more consistent to test than the naturally varied plant material in flower.

The study points to several reasons behind these inaccuracies. One is market pressure: the legal cannabis industry often rewards higher THC numbers with higher prices, pushing some growers and retailers toward “lab shopping,” where they choose testing labs that deliver higher potency results. Another challenge is the variability within the plant itself. Because cannabis flower is naturally inconsistent from bud to bud, achieving a truly representative test sample is difficult. The lack of federal testing standards also contributes to wide variations in laboratory methods and results across the industry.

These inaccuracies carry real consequences for consumers, especially medical patients who depend on precise dosing to manage health conditions. Misrepresented THC levels can lead to inconsistent treatment outcomes. Recreational users may also experience unpredictable effects or find that a product doesn’t deliver the potency they expected. Experts warn that an overemphasis on THC percentage alone has caused many consumers to overlook other important elements, such as minor cannabinoids and terpenes, which play a major role in the overall cannabis experience.

Researchers involved in the study emphasize the importance of establishing stronger oversight and standardized testing regulations. Reliable, transparent labeling is essential for ensuring that consumers—both medical and recreational—can make informed and safe purchasing decisions.