Health Warning Labels Research

Decades of research confirm that cigarette package warnings influence smoking behaviour. Here, we compile key studies on health warning effectiveness, from early text-only labels to modern graphic pictorial warnings. All findings come from peer-reviewed journals, government reports, and WHO documentation.

Health Warning Labels Research

Research on Warning Label Effectiveness

The scientific consensus is clear: larger, graphic warnings work better than small text labels. This finding holds across countries, age groups, and smoking status.

The International Tobacco Control (ITC) Policy Evaluation Project provides the most comprehensive data. Running since 2002, the ITC Project surveys smokers across 30+ countries to measure how tobacco policies affect behaviour. Findings consistently show that pictorial warnings:

  • Increase knowledge of smoking health risks
  • Prompt more thoughts about quitting
  • Lead to more quit attempts
  • Reduce smoking initiation among youth.

A 2016 meta-analysis published in Tobacco Control examined 37 experimental studies involving 33,613 participants across 48 independent samples. The analysis found that pictorial warnings were more effective than text-only warnings for 12 of 17 measured outcomes.

Warning size matters. Research published in Tobacco Control found that warnings covering 50% or more of the pack surface significantly outperform smaller warnings. Countries with the largest warning requirements show the strongest effects on risk perception.

“Health warnings on tobacco packages are among the most direct and prominent means of communicating with smokers.” — WHO FCTC Article 11 Guidelines

Key Academic Studies

Several landmark studies shape current tobacco warning policy.

Noar et al. (2016) Meta-Analysis

Dr. Seth Noar and colleagues at the University of North Carolina conducted a comprehensive meta-analysis of experimental research on pictorial cigarette pack warnings, published in Tobacco Control.

Key findings:

Outcome
Effect Size (d)
Interpretation
Cognitive elaboration (thinking about risks)
1.27
Large effect
Negative emotional response (fear, disgust)
0.60
Medium effect
Attention to warnings
Significant
Pictorial > text
Quit intentions
Significant
Pictorial > text

The researchers found that pictorial warnings attracted and held attention better, garnered stronger cognitive and emotional reactions, elicited more negative attitudes toward smoking, and more effectively increased intentions to quit.

A follow-up meta-analysis (Noar et al., 2020) examining 57 studies with 42,854 participants confirmed these findings and explored the psychological mechanisms behind warning effectiveness.

Hammond (2011) Systematic Review

Dr. David Hammond at the University of Waterloo published a comprehensive review of health warning messages on tobacco products in Tobacco Control. The review examined evidence from multiple countries and established that:

  • Canadian cigarette warnings introduced in 2001 led to increased quit attempts
  • Graphic warning labels are noticed more frequently than text warnings
  • Warning effectiveness declines over time without rotation
  • Plain packaging increases attention to health warnings

Dr. Hammond continues to lead research on tobacco labelling at the University of Waterloo, contributing to evidence that shapes policy in Canada and internationally. His research group’s recent work (2024-2025) has expanded to examine health warnings on e-cigarettes, cannabis, and alcohol products, demonstrating how principles from tobacco warning research apply across consumer health contexts.

Strahan et al. (2002) – Social Psychology of Package Warning Labels

One of the foundational studies on package warning labels was published by Strahan and colleagues in Tobacco Control in 2002. The research, titled “Enhancing the Effectiveness of Tobacco Package Warning Labels,” examined warnings from a social psychological perspective.

The study explored how message framing, imagery, and placement influence smoker behaviour and cognitive responses. Key findings established that warning label designs combining graphic images with clear text messages produce stronger emotional and cognitive reactions than text-only warnings.

This research directly informed Canada’s 2001 decision to become the first country requiring pictorial health warnings on cigarette packages, establishing the evidence base that dozens of countries have since followed.

ITC Project Longitudinal Studies

The International Tobacco Control Project, led by Dr. Geoffrey Fong at the University of Waterloo, tracks policy impacts across countries using longitudinal cohort surveys. Studies from the ITC Project have documented:

🇦🇺 Australia (2012 plain packaging): A study published in Tobacco Control found that after plain packaging implementation, smokers showed increased attentional orientation toward warnings, increased frequency of noticing warnings, and more thoughts about the harms of smoking. Separately, research found a 78% increase in calls to the Quitline associated with the introduction of plain packaging.

🇬🇧 United Kingdom (2016 standardised packaging): ITC surveys found that after implementation, noticing warnings, reading them, thinking about health risks, and avoidant behaviours all significantly increased.

🇨🇦 Canada (2012 larger warnings): Studies showed increased warning salience and cognitive responses following the introduction of larger pictorial warnings. However, a 2023 ITC study (Gravely et al.) evaluating Canada’s 2019 plain packaging found no significant change in warning salience or effectiveness, likely because Canada retained the same warnings that had been on packs for several years rather than introducing new images simultaneously.

🇸🇬 Singapore (2020 standardized packaging): Research published in 2024 (Ng et al.) found that smokers reported increased consideration of quitting after plain packaging implementation, adding to evidence that simultaneous introduction of standardised packaging and novel warnings produces measurable effects.

🇳🇴 Norway (2018 standardized packaging): A 2021 study (Moodie et al.) found no change in warning salience or effectiveness post-implementation. Like Canada, Norway introduced plain packaging while retaining existing warnings, supporting the hypothesis that novel warnings are necessary to see immediate improvements in warning response.

Brewer et al. (2016) Randomized Clinical Trial

A randomized controlled trial published in JAMA Internal Medicine assigned 2,149 adult smokers to receive their regular cigarettes with either pictorial or text-only warnings for four weeks. Smokers exposed to pictorial warnings were more likely to attempt quitting and to report sustained abstinence by the end of the trial.

UK Adult Tobacco Policy Survey (2016-2022)

A landmark longitudinal study published in October 2025 (Moodie, Best & Jones) tracked the same cohort of UK smokers across four waves: before standardised packaging (2016), shortly after (2017), two years post (2019), and five years post with refreshed warnings (2022).

Key findings comparing 2022 to pre-plain-packaging baseline (2016):

Measure
Odds Ratio
Interpretation
Noticing warnings often
1.68
68% more likely
Reading warnings closely
1.78
78% more likely
Thinking about warnings
1.49
49% more likely
Covering warnings
1.66
66% more likely
Using cigarette case
2.21
121% more likely
Forgoing cigarettes due to warnings
1.35
35% more likely

The study also found no significant differences between 2019 and 2022, when new warning images were introduced while maintaining the same format. This suggests that refreshing images alone, without changing warning size or layout, may prevent further decline but is insufficient to significantly increase effectiveness.

The researchers concluded that “standardised packs with pictorial warnings remain more salient and effective over time than fully-branded packaging with weaker warnings, and that this persisted for over five years.”

Japanese Residential Context Study (2026)

A January 2026 study (Zhao et al.) published in Public Health examined how individual circumstances shape warning responses among 170 Japanese smokers. Key findings:

  • Smokers living in detached houses (vs. apartments) viewed warnings as more effective in reducing overall smoking
  • Those with more household cohabitants perceived warnings as more effective
  • Heavier home smokers perceived labels as less effective at controlling household smoking
  • Many participants reported “feeling nothing” when seeing warnings

The researchers concluded that “residential environments of smokers shape how effectively they perceive warning labels,” calling for tailored antismoking policies that account for individual differences. This study highlights an emerging research direction: understanding how demographic and contextual factors modify warning effectiveness.

Types of Health Warnings

Tobacco warning labels fall into several categories based on content and format.

Text-Only Warnings

The earliest warning labels contained only text. The United States mandated the first cigarette warning in 1966: “Caution: Cigarette Smoking May Be Hazardous to Your Health.”

Text warnings remain common in countries with weaker tobacco labelling laws. Japan requires warnings covering only 30% of the pack surface, among the smallest in developed nations, and still does not mandate graphic images.

Research limitations of text-only warnings:

  • Easily ignored after initial exposure
  • Limited impact on low-literacy populations
  • Less memorable than images
  • Minimal emotional response

Pictorial Warnings

Pictorial warnings combine text with photographs or illustrations. Canada became the first country to require picture warnings in 2001.

Common pictorial warning themes include lung disease, oral cancer, cardiovascular damage, second-hand smoke effects on children, and mortality imagery. More than 140 countries now require pictorial health warnings on cigarette packages, covering approximately 66% of the world’s population.

Pictorial warnings work because they communicate risk instantly regardless of literacy, trigger emotional responses that reinforce memory, reach smokers each time they handle the pack, and cannot be avoided without covering the package.

Pictorial Warnings

Testimonial Warnings

Some countries feature real people sharing their experiences. The United States warning set includes photographs and statements from former smokers living with smoking-related diseases.

Barb Tarbox, a Canadian woman diagnosed with terminal lung cancer in September 2002, became one of Canada’s most prominent anti-smoking advocates. Despite smoking two packs daily for nearly 30 years since age 11, she spent her final months speaking to approximately 50,000 students across Canada about the consequences of smoking. She died on May 18, 2003, at age 42. Her image now appears on Canadian cigarette packs as part of the mandated health warnings, reaching millions of smokers annually.

Tarbox was posthumously awarded the Meritorious Service Medal in December 2003. Her story remains a powerful example of testimonial-based health communication.

Photograph of a woman smoking

Combined Warnings

Most countries now require combined text and pictorial warnings. The European Union Tobacco Products Directive mandates pictures covering 65% of the pack front and back.

Combined Warnings

Graphic vs Text-Only Warnings

Direct comparisons confirm which format works better.

The 2016 Noar meta-analysis found pictorial warnings outperformed text-only warnings across multiple measures. Participants exposed to pictorial warnings showed:

  • Greater attention to warnings
  • Stronger cognitive reactions (thinking about risks)
  • Stronger emotional reactions (fear, concern)
  • More negative attitudes toward cigarette packs
  • More negative attitudes toward smoking
  • Greater intentions to not start smoking
  • Greater intentions to quit smoking

Participants also perceived pictorial warnings as being more effective than text-only warnings across all perceived effectiveness measures examined.

Why Graphic Warnings Work

Several psychological mechanisms explain graphic warning effectiveness.

Fear appeals trigger protective motivation. Seeing concrete health consequences makes abstract risks feel personal and immediate.

Visual processing bypasses cognitive defences. Text can be rationalized. Images reach the emotional brain directly.

Repetition builds salience. A pack-a-day smoker potentially sees warnings an estimated 7,300 times per year (20 views per day multiplied by 365 days). A carton of cigarettes means even more warning exposures.

The “risk-as-feelings” hypothesis suggests that emotional reactions better explain in-the-moment decision-making than cognitive assessments. Research demonstrates the influence of emotion in health communication, especially fear as a motivator of behaviour change.

Limitations of Graphic Warnings

Research also identifies boundaries.

Wear-out reduces impact over time. The same images lose power after 12–18 months of exposure. Regular rotation addresses this, which is why most countries now require periodic updates to warning image sets. The 2025 UK longitudinal study confirmed this phenomenon: refreshing warning images without changing format prevented further decline but did not significantly increase warning salience.

Warnings alone are insufficient. Labelling works best as part of comprehensive tobacco control including taxation, smoke-free laws, advertising bans, and cessation support. Canada’s Tobacco Strategy progress report (January 2026) emphasises this integrated approach, noting that the country invested over $19 million in public education campaigns that complement pack warnings.

Interestingly, meta-analyses show that while pictorial warnings increase emotional responses and cognitive elaboration, they do not significantly change beliefs about the perceived likelihood or severity of smoking-related disease. The mechanism appears to work through affect rather than risk belief modification.

Public Health Perspectives

Health organizations worldwide endorse graphic pictorial warnings as evidence-based policy.

WHO Position

The WHO tobacco control guidelines under FCTC Article 11 recommend:

  • Warnings covering at least 50% of principal display areas
  • Use of pictures or pictograms
  • Rotation of warning messages
  • Messages in the principal language(s) of the country

The WHO notes that health warnings are particularly cost-effective. Unlike advertising campaigns, warnings reach smokers at the point of consumption at no ongoing cost to governments.

Government Health Agencies

Health Canada’s January 2026 progress report describes health warnings as “the most direct and prominent means of communicating with smokers.” Canada pioneered graphic warnings in 2001 and has continued strengthening requirements. Key statistics from the report:

  • Tobacco use declined from 29% (2001) to 13% (2024)
  • Adult smoking reached 11% in 2024 – among the lowest rates globally
  • Youth smoking fell below 2% – a record low
  • Approximately 300,000 Canadians quit smoking in 2024
  • Projections show Canada on track to reach 5.1% smoking prevalence by 2035

The report notes that approximately one-third of Canadian smokers read pack inserts monthly, and those who read them more frequently show higher quit rates providing direct evidence linking warning engagement with cessation success.

The Australian Department of Health reports that plain packaging with enhanced graphic warnings contributed to continued decline in smoking prevalence, from 15.1% in 2010 to 11.0% in 2019.

The European Commission concluded in its impact assessment that larger pictorial warnings would reduce smoking rates across the EU.

Medical and Research Organizations

The American Cancer Society, British Medical Association, Cancer Council Australia, and numerous other health organizations advocate for the strongest possible warning requirements based on research evidence.

Warning Label Effectiveness by Population

Research shows warnings affect different groups in different ways.

Youth

Young people respond strongly to graphic warnings. Studies from Canada and Australia show that pictorial warnings reduce the appeal of trying cigarettes, increase perception of health risks, and counter tobacco marketing influences.

Long-term studies of Australian adolescents from 2011 to 2017 showed continuing impact on young people’s perceptions of cigarettes following plain packaging implementation. Tobacco continued to be viewed as less appealing over the entire study period.

Canada’s 2026 progress report notes that youth smoking (ages 12-17) has reached a record low of less than 2%. The report states: “Preventing young people from a lifetime of smoking-related harm is one of the most significant public health achievements of the past 25 years.”

Current Smokers

For existing smokers, warnings serve as repeated prompts to consider quitting. The ITC Project reports that smokers who notice warnings more frequently are more likely to think about the health risks of smoking, think about quitting, attempt to quit, and succeed in quitting.

Heavy smokers (20+ cigarettes daily) see their pack most frequently and receive the highest warning exposure.

A 2025 ITC study (Dhungel et al.) examined trends in noticing and responding to health warning labels from 2002 to 2022 across four countries (Canada, US, UK, Australia). The longitudinal analysis provides two decades of evidence on how smokers’ responses to warnings have evolved as policies strengthened.

Former Smokers

Even for those who have quit, warnings reinforce the decision to stay smoke-free. Research from the United Kingdom shows that graphic warnings remind former smokers why they quit, supporting abstinence maintenance.

Future Directions in Tobacco Warning Research

Current research explores several new approaches.

Warnings on Individual Cigarettes

Canada became the first country to require health warnings printed directly on individual cigarettes (July 2024), followed by Australia (April 2025). This ensures warnings reach smokers even when packs are hidden or transferred to cases.

Early research in the European Respiratory Journal (Duan et al., 2026) examined Canadian cigarette sales in the first six months post-implementation. Additional studies from the University of Waterloo (Thrasher et al., 2025; Sun et al., 2025; Hackworth et al., 2024-2025) have evaluated smoker responses and policy support for this world-first approach.

Novel Warning Rotation

Evidence suggests warnings should be updated every 12–24 months to prevent wear-out. The 2025 UK longitudinal study found that refreshing images while maintaining the same format may slow decline but is insufficient to significantly increase effectiveness suggesting format changes, not just new images, may be necessary.

Dissuasive Packaging Design

Beyond plain packaging, research tests whether specific colours reduce product appeal. Australia’s drab brown (Pantone 448 C) was selected for its unappealing qualities. 27 countries have now adopted standardised packaging, with Thailand, Singapore, Myanmar, and Lao PDR leading in Asia.

Comprehensive Product Standards

Australia’s 2025 reforms show how warnings increasingly integrate with broader regulation – banning flavours (menthol, clove), crush balls, and misleading terms (“smooth,” “gold”) while standardising pack quantities and cigarette dimensions.

Individual Differences

Emerging research examines tailored approaches. A 2026 Japanese study (Zhao et al.) found residential context affected warning perception, with researchers calling for policies that account for individual differences – a potential shift from one-size-fits-all warnings.