Could there be a "safer" approach to cannabis consumption? Experts are now advocating for new consumption limits.
With the rise of cannabis use throughout Europe, researchers based in the United Kingdom have introduced a proposed weekly limit for cannabis consumption, akin to existing guidelines for alcohol intake, aimed at fostering safer usage practices.
A study conducted by the University of Bath and published in the journal Addiction has put forth these recommendations, which focus on the levels of tetrahydrocannabinol (THC)—the key psychoactive compound in cannabis. This approach takes into account not only the potency of the product but also the quantity consumed.
Rachel Lees Thorne, the lead researcher from the Department of Psychology at Bath, emphasized, "Our primary objective with these new guidelines is to minimize harm. The only truly safe level of cannabis use is complete abstinence." However, she noted that for individuals who either choose to continue using cannabis or feel unable to stop, the aim is to facilitate a reduction in their risk of harm.
The research team recommends that adults should limit their intake to eight THC units per week. This limit translates to approximately 40 mg of THC or about one-third of a gram of herbal cannabis.
These guidelines encourage users to focus on THC units instead of merely considering how often they use cannabis. To clarify, each THC unit corresponds to five milligrams. Tom Freeman, a senior researcher involved in the study, stated, "Establishing safer use thresholds based on standard THC units can empower individuals to better understand their usage levels and make informed decisions regarding their health.” He further noted that public health organizations and healthcare providers could utilize these guidelines to communicate risks effectively and monitor reductions in usage over time.
To derive these limits, the research team reviewed data from separate studies conducted at University College London, particularly the CannTeen study. This study followed 150 cannabis users over the course of a year, examining their weekly THC consumption and the occurrence of cannabis use disorder (CUD).
CUD is diagnosed when cannabis use leads to significant distress or disrupts daily life, with estimates suggesting it affects around 22 percent of regular cannabis users, leading to cravings and addiction. The Bath research team discovered that the likelihood of developing CUD increases for adults when consumption exceeds eight THC units per week, with severe cases spiking above 13 THC units per week.
Cannabis use can exacerbate various physical and mental health issues, such as chronic respiratory problems, dependence on cannabis, and psychotic symptoms. The risks tend to escalate with early initiation of use, high-potency products, and patterns of frequent or prolonged usage.
As cannabis becomes more accessible in legal markets globally, Freeman remarked, "It is increasingly vital to assist consumers in making informed choices about their cannabis use." Currently, cannabis stands as the most widely used illicit substance in Europe, with national surveys revealing that approximately 8.4 percent of adults—around 24 million individuals aged 15 to 64—have used cannabis in the past year, according to data from the European Union Drugs Agency (EUDA). Recent estimates indicate that about 4.3 million Europeans are regular consumers, using cannabis daily or nearly every day.
Regarding cannabis regulations across Europe, the substance is subject to stringent controls, and commercial recreational sales remain largely prohibited. However, several countries have decriminalized personal use or are enacting partial legislation; medical cannabis use is permitted under varying conditions in most European nations.
Malta became the first country in the European Union to legalize adult-use cannabis in 2021, allowing for the possession of small quantities, home cultivation, and the establishment of non-profit cannabis associations for distribution. Following this, Luxembourg approved limited home growing and private use, while Germany permits restricted home cultivation, possession of small amounts, and non-profit cannabis growing clubs. Furthermore, both the Netherlands and Switzerland are implementing or preparing pilot programs for regulated sales in controlled environments, including cannabis flowers, resin, oils, and edibles.
