Experts Propose Weekly THC Limits to Promote Safer Cannabis Use

New guidelines aim to reduce risks of cannabis use disorder and other health concerns as consumption rises across Europe

Apr. 10, 2026 at 5:52pm by

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A glowing, neon-outlined cannabis leaf against a dark background, conceptually representing the new guidelines for safer cannabis use.As cannabis use rises across Europe, new guidelines aim to promote safer consumption through standardized THC limits.San Francisco Today

Researchers from the University of Bath have introduced groundbreaking guidelines for safer cannabis use, proposing a weekly limit of 8 THC units (equivalent to 40 mg of THC or one-third of a gram of herbal cannabis). The goal is harm reduction, acknowledging that complete abstinence may not be realistic for many users. The focus is on both potency and quantity, with each unit representing 5 mg of THC. Experts argue this could revolutionize how people perceive their consumption and help public health bodies communicate risks.

Why it matters

Cannabis is the most widely used illicit drug in Europe, with an estimated 24 million adult users annually. As accessibility increases, clear guidelines are needed to address the rising rates of cannabis use disorder and other health concerns. These proposed thresholds aim to provide a harm reduction framework for those unwilling or unable to quit, while also informing policy and public education efforts.

The details

The guidelines are based on data from the CannTeen study at University College London, which tracked 150 cannabis users over a year. The findings showed that the risk of cannabis use disorder, marked by addiction and cravings, escalates sharply above 8 THC units per week, with severe cases spiking beyond 13 units. Factors like early onset use, high-potency products, and long-term habits amplify these risks exponentially.

  • The study was published in April 2026 in the journal Addiction.
  • The CannTeen study that informed the guidelines was conducted over the course of a year.

The players

Rachel Lees Thorne

The lead researcher on the study, who states the goal is harm reduction while acknowledging that complete abstinence may not be realistic for many users.

Tom Freeman

A senior researcher on the team, who argues that standardizing THC units could revolutionize how people perceive their cannabis consumption.

University of Bath

The institution where the research team is based and the study was conducted.

European Union Drugs Agency (EUDA)

The agency that reports an estimated 24 million adults in Europe use cannabis annually, with 4.3 million using it daily or near-daily.

CannTeen study

The research project at University College London that tracked 150 cannabis users over the course of a year, providing the data that informed the new guidelines.

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What they’re saying

“Our goal is harm reduction, but we must be realistic—many won't stop using.”

— Rachel Lees Thorne, Lead researcher

“Standardizing THC units could revolutionize how people perceive their consumption.”

— Tom Freeman, Senior researcher

What’s next

The proposed guidelines will now be reviewed by public health authorities and policymakers across Europe, who will determine if they should be adopted as part of broader cannabis regulation efforts.

The takeaway

As cannabis use continues to rise in Europe, these new guidelines represent an attempt to strike a balance between harm reduction and pragmatism. By focusing on THC content and quantity, the researchers aim to provide a framework that empowers users to make more informed decisions about their consumption, while also informing public education and policy. However, the debate over the appropriate level of regulation remains complex and ongoing.