Background: Commercialized cannabis markets may improve consumer welfare by increasing product variety and safety, but marketing activities and regulatory capture by industry actors may encourage use of high-potency products, which may be associated with increased risk of harms.

Objectives: Describe how California’s legal cannabis retail market has evolved in terms of potency (delta9-tetrahydrocannabidiol [THC]) and potency-adjusted price; and assess how policy and market changes affect the reliability of labeled THC information.

Methods: Using information on nearly 800 million transactions from California’s Cannabis Track-and-Trace system from 2019-2024, we (1) present descriptive statistics on THC and price per milligram THC over time, across jurisdictions, and across testing facilities; and (2) assess the effects of lab closures and state policy changes on indicators for mislabeling of THC on product offerings.

Results: The volume of THC sold has increased dramatically, reflecting both a shift toward higher-potency product types (e.g., vape and infused pre-roll products show median labeled percentages THC over 85% and 40%) and increasing potency within product type, although we document important differences by jurisdiction. We show a portion of this trend reflects THC “inflation” by testing facilities, although high-potency products remain dominant, with most counties having a median price per 10-milligram “dose” less than 30 cents.

Implications: The commercial cannabis market in California has become increasingly dominated by high-THC products, although some portion of this appears to reflect trends in THC inflation. Policymakers should take steps to ensure accurate labeling (or accurate characterization of uncertainty) of THC in legal cannabis products.