Cannabis vapor systems—devices that heat cannabis flower, oils, or extracts to produce inhalable vapor rather than smoke—have become increasingly popular. They promise fewer harmful by-products than combustion. But what does research say about their impact on lungs, particularly for people with COPD (Chronic Obstructive Pulmonary Disease) or those at risk?

What the Research Tells Us So Far

Comparisons: Vapor vs. Smoke

• Several studies suggest that vaporizing cannabis exposes users to less carbon monoxide, fewer combustion toxins, and reduced markers of airway irritation compared to smoking cannabis. Using a vaporizer instead of smoking appears to lower chronic respiratory symptoms in some users.
• In particular, a 2021 review (“Cannabis and Lung Health: Does the Bad Outweigh the Good?”) noted that replacing smoked cannabis with vaporized forms may reduce various pulmonary complications.

COPD, Breathlessness, and Airway Function

• A clinical trial looked at people with advanced COPD who inhaled a single dose of vaporized cannabis. The trial found no clinically meaningful worsening or improvement in airway function, breathlessness during exertion, or exercise endurance vs. control. 
• That suggests that for some people, one-time vapor exposure may not immediately worsen COPD symptoms—but that does not prove long-term safety.

Adverse Effects & Special Risks

• Even with vaping, respiratory symptoms such as cough, wheezing, sputum production, or sensation of chest tightness are reported, especially among frequent or heavy users. 
• Adolescents who vape cannabis have shown elevated risk of respiratory symptoms compared to ones who only vape nicotine or only smoke marijuana. 
• Use of unregulated or illicit vapor products has been implicated in serious lung injuries. For example, the 2019–2020 EVALI outbreak was largely linked to THC vaping cartridges contaminated with vitamin E acetate or other harmful diluents. 

Uncertainties and Gaps

• Long-term studies are limited. It is not yet well known whether chronic vapor use (with cannabis) leads to progressive lung function decline or contributes to COPD development in those without COPD.
• Many studies have confounding factors—tobacco use, frequency/dose of cannabis, inhalation patterns (breath-holding etc.), different products (flower vs concentrates, oils with additives) make results variable.
• There is less evidence on how vaporizing high-concentration extracts, flavoring agents, or untested additives affect lung health over time.

What Consumers Should Understand

For anyone considering or already using cannabis vapor systems, especially those with COPD or risk factors for lung disease, here are key points:

1. Cannabis vaporization is likely less harmful than smoking, but not harmless. Vapor still carries risks to the airways.
2. Product quality matters a lot.
   • Use regulated, tested cartridges or oils.
   • Avoid products from unknown sources that might contain harmful additives or contaminants (e.g. diluents, thickening agents, vitamin E acetate).
   • Be aware that potency and concentration of THC or other cannabinoids affect inhalation intensity and possibly lung exposure.
3. Minimize inhaled exposure.
   • Use low-temperature vaporizers that avoid overheating.
   • Avoid holding vapor in the lungs longer than necessary.
   • Limit frequency of vaping sessions.
4. Monitor symptoms carefully.
   • If you have COPD (or suspect you might), pay attention to increases in cough, shortness of breath, mucus production, or worsened exercise capacity.
   • Keep regular medical checkups and lung function testing if possible.
5. Explore non-inhaled alternatives when appropriate. Edibles, tinctures, topical formulations etc., may offer therapeutic effects without direct impact on the respiratory system (though they have their own risks and differences in effects).
6. Don’t assume “vapor = safe” because many of the long‐term effects are still unknown.

Bottom Line

• Vapor systems have promise for reducing harm compared to traditional smoking of cannabis, especially with respect to respiratory irritation and possibly lowering exposure to certain toxins.
• But for people with COPD or at risk, there is no fully proven safe level of inhaling cannabis vapor; risk is not zero.
• Taking steps to reduce exposure (product quality, inhalation methods, frequency), monitoring lung health, and choosing less risky delivery methods are the best current strategies based on available evidence.