The Tobacco and Vapes Bill: What could it mean for cannabis use in the UK?

Hannah Walsh, Matilda Nottage, Katherine Sawyer, and Chloe Burke – founding members of the Cannabis and Nicotine co-use Special Interest Group (CaN-SIG) – explore the implications of the Tobacco and Vapes Bill for people who use both tobacco and cannabis.

The Tobacco and Vapes Bill was initially announced in November 2023 under the previous government, and introduced by the current government in November 2024. It sets out a range of measures aiming to create a smoke-free generation and to reduce the appeal and availability of vaping products. Measures include the gradual introduction of a ban on the sale of tobacco products across the UK. This means that children born on or after 1 January 2009 (i.e. aged 15 and younger in 2024) will never be able to be legally sold tobacco products, including herbal smoking products and cigarette papers.

The proposed measures could be a big step towards reducing tobacco-related harms. Modelling published by the previous government in 2023 suggests that if successfully implemented, the Tobacco and Vapes Bill could reduce the number of young people taking up tobacco smoking by as much as 90%. This would result in 1.7 million fewer people smoking tobacco by 2075 and prevent up to 115,000 new cases of the four main smoking-related illnesses (lung cancer, stroke, coronary heart disease, and chronic obstructive pulmonary disease). However, there could be unanticipated consequences of these regulations for people who co-use cannabis and tobacco, including greater cannabis consumption in place of tobacco, and a switch to non-combustible products.

The current state of cannabis and tobacco use

‘Cannabis–tobacco co-use’ is an umbrella term used in academic and clinical settings to capture people who use both substances. This term is broadly made up of two types of co-use:

• Using both separately (‘concurrent co-use’): for example, someone might have used cannabis in the last month every night before going to bed and regularly smoked cigarettes during the day over the last month.
• Mixing both together (‘co-administration’): for example, combining dried herbal cannabis with rolling tobacco in a ‘spliff’ or ‘joint’.

The reasons people report for mixing cannabis and tobacco are varied and include lower cost, the possibility of varying the dose (e.g. adjusting the ratio of tobacco to cannabis), and improved taste or burn.

In European countries, it is far more common for people who smoke cannabis to mix in tobacco compared to other countries like the US and Canada. According to data from the Action on Smoking and Health (ASH) survey, 43% of people who use cannabis in Great Britain also smoke cigarettes and 61% mix cannabis with tobacco (e.g. in a spliff or joint).

Why the new legislation could lead to an increase in cannabis use

Predicting the impact of changes in the legal status of substances is inherently challenging, particularly for people who already use illegal substances. However, restricting the sale of tobacco products sends a strong signal about the risks associated with smoking, which could reshape public perceptions of tobacco’s harmfulness.

Assuming that a change in legal status affects behaviour, making tobacco more difficult to obtain could mean that people who co-administer cannabis with tobacco could put less tobacco in their method of use and substitute with more cannabis. Although reducing the amount of tobacco could reduce harms from tobacco smoking, increasing the amount of cannabis could increase harms from cannabis. There is consistent evidence that higher frequency cannabis use, particularly with high-potency cannabis, is associated with increased risk of cannabis use disorder and psychosis.

On the other hand, tobacco use may continue despite the bill’s provisions. We see that despite cannabis being currently illegal in the UK, rates of cannabis use are high among youth – 15.4% of adolescents report cannabis use by age 15 and 3% by age 13. This suggests that tobacco use including co-administration with cannabis may persist regardless of policy, which raises uncertainty about whether the legal changes targeting tobacco will significantly reduce co-use with cannabis, a behaviour that is already widespread despite the illegal status of cannabis.

Why the new legislation could lead to people switching from smoking to non-combustible methods of cannabis use

For people who choose to smoke cannabis as their main mode of consumption, there are specific motivations for mixing cannabis with tobacco. If access to tobacco becomes more restricted, it’s possible that people would explore switching to non-combustible methods, including vapourisers (e.g. dry-herb vapouriser, vape pen), ingestion (e.g. edibles), and topical applications (e.g. lotions, balms). This could have a positive impact, as switching away from combustible methods may reduce the overall harms from cannabis use. However, alternative delivery methods can come with their own risks, particularly in a market where these products are not regulated. For example, edibles have a delayed onset of psychoactive effects compared to combustible methods, which could result in the use of larger doses than intended and increased adverse effects.

There are also serious risks associated with unregulated illegal vaping products, particularly among young people who may be less informed about what they are consuming. Unlike nicotine vapes, THC-containing vapes are illegal and unregulated in the UK, leading to safety concerns about their use. Beginning in 2019, the US saw a surge in cases of severe lung illness related to vaping which has been linked to the use of illegal THC vapes. Vitamin E acetate, an oil used in some THC vapes, was specifically implicated in these cases. Other harmful ingredients may also be present in unregulated products.

A concern recently raised in the House of Commons is the presence of synthetic cannabinoids sometimes known as ‘spice’ in illicit THC vapes. These synthetic compounds were implicated in the only two vaping-related deaths reported in the UK as of 2020. Alarmingly, their use may be increasing. A recent study that tested vapes seized from 27 schools across England found synthetic cannabinoids in 17.5% of the samples, across 78% of schools. In contrast, only 1.6% of the tested vapes contained THC. The study’s authors suggest that students may be unknowingly purchasing synthetic cannabinoid vapes, believing they are buying THC vapes.

Assessing the impact on a ‘hidden population’

It is difficult to assess the causal impact of any policy; other factors can influence people’s behaviours. One review that examined the impact of cannabis policy on use (e.g. frequency of use) compared cannabis use behaviours between US states which legalised recreational cannabis and those which have not. However, any observed changes in cannabis use behaviours could be due to other factors in legalised vs non-legalised settings, such as attitudes towards drug use and sociodemographic characteristics.

As this essay has highlighted, the impact of policy changes can also extend beyond the behaviours which they target. The proposed measures in the Tobacco and Vapes Bill, for example, could feasibly reduce tobacco-related harms but also have unintended consequences for people who co-use tobacco and cannabis.

To effectively monitor the impact of the Tobacco and Vapes Bill, we need sufficient data. People who co-use tobacco and cannabis are not currently reflected in smoking prevalence data, and therefore represent a ‘hidden’ population of people exposed to tobacco harms. Typical routes of questioning may not work if people who co-use tobacco and cannabis don’t see themselves as ‘smokers’. For example, ask them if they are a cigarette smoker, and they may say ‘no’. But ask if they use tobacco with their cannabis, and their answer might be ‘yes’.

Once we have a better picture of this hidden population, we need to understand patterns of co-use in more detail (e.g. modes of administration, type and expected potency of cannabis, type of tobacco and/or nicotine containing product). Specific data will allow for better understanding of the impact of a policy, especially in the context of cannabis and tobacco co-use which can take many forms.

Lack of co-use measurement in population-level surveys (e.g. Crime Survey for England and Wales) has been identified as a key barrier to accurately assessing the prevalence and health impacts of cannabis-tobacco co-use. Encouragingly, this information is increasingly being collected. For example, The International Cannabis Policy Study (ICPS) is an annual survey across different countries, including the UK, that has been designed to evaluate the impact of cannabis policies and includes detailed assessment on frequency and methods of consumption. Along with the NIHR-funded Policy Research Unit in Addictions, this means we are now in a better position to monitor trends in cannabis-tobacco co-use and potential health impacts.

by Hannah Walsh, Matilda Nottage, Katherine Sawyer, and Chloe Burke