10 Years of U.S. Cannabis Potency by Region: THC Keeps Climbing Everywhere | Research

The takeaway

DEA-seized cannabis samples from 2013-2022 show THC concentrations rising across all U.S. regions, with virtually all other cannabinoids (including CBD) present at negligible levels — creating an increasingly THC-dominant market.

Read this if you care about cannabis potency trends — this is the most comprehensive U.S. data available, and it shows the same pattern everywhere.

What the researchers found

This is the definitive U.S. potency trend study. Researchers at the University of Mississippi — the institution that has analyzed DEA-seized cannabis for decades — examined cannabinoid concentrations across all U.S. regions over 10 years (2013-2022).

The headline finding is striking in its uniformity: regardless of which state or region the cannabis was seized in, or whether it came from the illicit market or a state medical marijuana program, the cannabinoid profile was essentially the same. THC dominated at over 10% for most samples, while all other cannabinoids — including CBD, CBG, and CBN — were present at less than 0.5-1%. The cannabis market, legal and illegal, has converged on a single product type: high THC, virtually everything else negligible.

The regional analysis showed THC rising everywhere, with no geographic pocket of lower-potency cannabis remaining. This debunks the idea that certain regions or market types (medical vs. recreational vs. illicit) offer meaningfully different potency profiles. Whether seized by the DEA in the Western states, Midwest, Northeast, Southeast, or South, the cannabis was basically the same product.

This convergence toward THC monoculture is the opposite of what a therapeutically oriented market would look like. Medical cannabis was supposed to offer diverse cannabinoid profiles for different conditions. Instead, both legal and illegal markets are optimizing for the same thing: maximum THC.

Why it matters

This is the most comprehensive and authoritative potency trend data available for the U.S., coming from the lab that has been the federal reference standard for decades. The finding that legal medical marijuana programs produce the same THC-dominant profile as illicit cannabis undermines the argument that legal markets provide more diverse therapeutic options. For public health, the steady national rise in THC concentration means population-level THC exposure is increasing even if the number of users stays the same.

The numbers in context

10-year study period (2013-2022). Six U.S. regions analyzed. All high-THC samples had >10% THC regardless of region. All other cannabinoids <0.5%, with exceptions of CBG (<1%) and CBN (<1%). No meaningful potency differences between regions or between illicit and medical program samples.

How the study worked

Observational analysis of illicit cannabis samples seized by the U.S. Drug Enforcement Administration from 2013 to 2022. Samples categorized by geographic region: Western, Midwest, Northeast, Southeast, Southern, plus Alaska and Hawaii. Cannabinoid content analyzed using a validated gas chromatography with flame ionization detector method. Compared samples from both illicit seizures and state medical marijuana programs.

Who was studied

Cannabis samples seized by the DEA from various regions in the US over a 10-year period.

What this study cannot tell us

Data comes from DEA seizures, which may overrepresent illicit market cannabis and larger operations. Comparison with state medical program samples partially addresses this but may not represent the full range of products available in dispensaries (e.g., CBD-rich products may not be captured by DEA seizures). GC analysis after decarboxylation measures total potential THC, not the THC concentration a user would experience. Trends in cannabis concentrates, edibles, and vape products are not captured by this flower/plant material analysis.

How to read the evidence

Observational analysis from the federal reference laboratory using validated analytical methods. The data is authoritative for what it measures (seized samples), though it may not capture the full range of products in regulated dispensaries.

When this study was published

Published in 2024 with data through 2022. This is the most current comprehensive U.S. potency dataset available.

The bigger picture

This is the authoritative U.S. companion to the potency cluster already in the database: RTHC-00071 (rising U.S. potency), RTHC-00106 (Rome hashish doubling), RTHC-00049 (European trends), and RTHC-00086 (THC:CBD ratios in dispensaries). This study clinches the point: potency escalation is nationwide, affects both legal and illegal markets, and is producing a THC monoculture where other potentially therapeutic cannabinoids are bred and processed out of existence.

Replication

Not stated in abstract.

Funding

Not reported in abstract.

Conflicts of interest

Not reported in abstract.

Questions still open

Why have both legal and illegal markets converged on THC maximization despite growing consumer interest in CBD? Would regulatory incentives (tax breaks for balanced-ratio products, potency caps) shift the market toward more diverse cannabinoid profiles? Is there a biological ceiling for THC concentration in cannabis flower, or will potency continue to rise? Has the disappearance of CBD from most cannabis products contributed to the mental health concerns associated with high-potency use?

Read the original research

A 10-year trend in cannabis potency (2013-2022) in different geographical regions of the United States of America.

Frontiers in public health, 12, 1442522

Frontiers in Public Health is a reputable journal that publishes research on health-related issues.

View on PubMed ↗Publisher’s paper ↗

Citation

ElSohly, Mahmoud A; Majumdar, Chandrani G; Chandra, Suman; Radwan, Mohammed M. (2024). A 10-year trend in cannabis potency (2013-2022) in different geographical regions of the United States of America.. Frontiers in public health, 12, 1442522. https://doi.org/10.3389/fpubh.2024.1442522