'Natural' Does Not Mean Safe: IIT-Gandhinagar Study Raises Red Flag Over Herbal Cigarettes

Marketed as tobacco-free, chemical-free and even therapeutic, herbal cigarettes have increasingly found takers among young adults and health-conscious consumers seeking what they perceive as a safer alternative to conventional smoking. However, a new study led by researchers from the Indian Institute of Technology Gandhinagar (IIT-GN) has found that these products may produce emissions that are as harmful as, or potentially more harmful than, those from tobacco cigarettes.

The findings, published in the peer-reviewed Journal of Hazardous Materials, come at a time when India is battling a growing burden of tobacco-related diseases while alternative smoking products continue to enter the market with regulatory oversight that differs from that applied to tobacco products.

Researchers warn that the widespread perception that “herbal” automatically means “harmless” could be placing thousands of consumers at risk.

“Our findings challenge the widely held belief that tobacco-free means risk-free,” said Prof. Sameer Patel, Assistant Professor at the Department of Civil Engineering and Chemical Engineering, IIT Gandhinagar, and co-coordinator of the Dr. Kiran C. Patel Centre for Sustainable Development.

“Emissions from herbal cigarettes are comparable to or exceeded those from tobacco cigarettes on nearly every metric we measured. Leaf-wrapped herbal variants turned out to be the most hazardous of all the samples tested,” he said.

Growing Popularity, Growing Concern

The concern is particularly relevant for India, home to one of the world's largest tobacco-consuming populations. According to the Global Adult Tobacco Survey (GATS), millions of Indians continue to use smoked tobacco products, while the market for alternative products marketed as “natural” or “wellness-oriented” is steadily expanding.

Many herbal cigarette brands advertise themselves as nicotine-free products are marketed with claims of relieving stress, improving sleep, reducing anxiety, or helping smokers quit tobacco. Such claims often create an impression of safety despite limited scientific evidence supporting them.

To examine these claims, IIT-GN researchers collaborated with scientists from the University of Illinois Urbana-Champaign to compare the emissions generated by herbal and tobacco cigarettes commonly sold in the Indian market.

The team analysed smoke from two leading tobacco cigarette brands and four popular herbal cigarette variants containing ingredients such as basil, clove, cinnamon, mint, green tea, chamomile and water lily.

Notably, some of the herbal products used tendu leaves — the same leaves commonly used in bidis, India's most widely consumed smoking product.

Smoke Found To Contain Dangerous Particles

To ensure accurate measurements, researchers burned each cigarette in a specialised automated smoking chamber designed to mimic human inhalation patterns.

The emissions were then analysed for their physical and chemical properties, including particle concentration, metal content and oxidative potential — a measure of the smoke's ability to generate harmful molecules that can damage cells and tissues.

One of the most striking findings was that herbal cigarettes emitted approximately 20 per cent higher concentrations of ultrafine particles smaller than 500 nanometres compared to tobacco cigarettes.

These microscopic particles can penetrate deep into the lungs and enter the bloodstream, where they have been linked to cardiovascular disease, respiratory illness and chronic inflammation.

The researchers also found that particulate matter generated by herbal cigarettes displayed significantly higher oxidative potential than smoke from tobacco cigarettes.

“Tendu-leaf-wrapped variants showed oxidative potential roughly 49 per cent higher than paper-wrapped versions,” the study noted.

Oxidative stress is considered a key biological mechanism underlying lung injury, heart disease and several chronic illnesses.

‘Nicotine-Free’ Does Not Mean Reduced Harm

According to the researchers, consumers often equate the absence of nicotine with safety, a misconception that the study strongly challenges.

“That finding is important because many consumers associate nicotine-free products with reduced harm,” said Prof. Vishal Verma, Associate Professor of Environmental Engineering at the University of Illinois Urbana-Champaign and a collaborator on the study.

The study revealed another surprising finding. One herbal cigarette containing basil showed the highest concentration of lead among all products tested despite being promoted as “chemical-free” and suitable for a healthy lifestyle.

The presence of toxic metals is particularly concerning because long-term exposure has been associated with neurological, cardiovascular and developmental health effects.

Regulatory Considerations

Public health experts say the findings expose an important regulatory gap.

India's Cigarettes and Other Tobacco Products Act regulates tobacco products through mandatory health warnings, advertising restrictions and public smoking regulations. However, products marketed as tobacco-free often fall outside these provisions.

This creates a situation where herbal cigarettes can be promoted using wellness-oriented language while not being subject to some of the safeguards applied to conventional tobacco products.

“Several herbal cigarettes we tested were marketed with claims of relieving cough, improving sleep, or easing anxiety. However, there is limited scientific evidence evaluating the emissions and toxicological impacts of these products,” said Dr. Alok Kumar Thakur, the study's lead author and former Prime Minister Research Fellow at IIT-GN.

The researchers stressed that the study does not directly measure disease outcomes in humans. Instead, it evaluates the physical and chemical characteristics of smoke and their biological reactivity.

“Combustion, fine particles, soot, trace metals, and the wrapper around them all matter more than what is written on the box,” said Dr. P. S. Ganesh Subramanian, a co-author of the study.

Implications for India

The findings arrive amid renewed discussions on tobacco control around World No Tobacco Day 2026, whose theme this year focuses on countering the appeal of nicotine and tobacco products.

Experts say the study should prompt policymakers to examine whether herbal cigarettes require the same scrutiny as conventional smoking products.

For a country already facing a heavy burden of cancer, chronic lung disease, heart disease and stroke linked to smoking, the emergence of unregulated products marketed as healthy alternatives could create a new public health challenge.

The message from researchers is clear: replacing tobacco with herbal smoke does not eliminate the risks associated with inhaling combustion products. As evidence accumulates, they argue, regulation and consumer awareness must keep pace with marketing claims.

The label “herbal,” the study suggests, should not be mistaken for a guarantee of safety.