A controlled Johns Hopkins trial gave infrequent cannabis users equal THC doses by smoking and vaporization. The delivery method changed both blood THC and how strongly participants felt the effects.
The crossover trial
Seventeen healthy adults who had not used cannabis in the previous 30 days completed six double-blind sessions. Each participant received 0, 10, or 25 mg THC through either smoked cannabis or a dry-herb vaporizer.
What the researchers found
Both active doses produced effects, but vaporized cannabis generally caused stronger subjective drug effects and greater impairment than smoked cannabis at the same dose. At 25 mg, average peak blood THC was approximately 14.4 ng/mL after vaporization and 10.2 ng/mL after smoking.
The 25 mg dose caused pronounced effects in this infrequent-use group, including anxiety, paranoia, and vomiting in some sessions. This is important context: the experiment was designed to measure controlled effects, not to recommend a dose.
Why might vaporization deliver more?
Combustion destroys part of the cannabinoids as plant material burns and also creates smoke byproducts. A dry-herb vaporizer heats flower without intentionally burning it. Device temperature, chamber design, flower preparation, inhalation, and user technique all influence how much THC becomes available.
A smaller pilot study also found comparable THC exposure from vaporization with substantially lower carbon monoxide than smoking. However, that result was device-specific and does not establish that every vaporizer or every vaping product is safe.
Dry-herb vaporization is not the same as an oil cartridge
The Johns Hopkins trial used cannabis flower in a controlled dry-herb vaporizer. Its findings should not be transferred to unregulated vape oils, cartridges, concentrates, additives, or different devices.
What this means for switching methods
- Do not assume a familiar smoked amount will feel identical when vaporized.
- Use a smaller first amount when changing devices or methods.
- Wait before taking more, especially if use is infrequent.
- Follow the device instructions and avoid damaged or contaminated products.
- Never drive while impaired.
How this fits with smoking research
Method is one variable among many. Within smoking, packing and airflow, puff timing, and potency compensation can also change exposure.
Frequently asked questions
Does a dry-herb vaporizer get you higher than smoking?
In the Johns Hopkins study, vaporization produced stronger effects at equal controlled doses in infrequent users. That does not guarantee the same result for every device, flower, or person.
Is dry-herb vaping harmless?
No inhaled product should be described as harmless. Vaporization avoids intentional combustion, but temperature, contaminants, device materials, and individual health still matter.
Why did equal THC doses produce different blood levels?
The two methods have different delivery efficiencies and losses. Combustion, device performance, and inhalation behavior all affect the delivered dose.
Compare common consumption methods
See how flower, concentrates, and vape products differ before choosing a format.
Sources and research notes
- Spindle and colleagues, Acute Effects of Smoked and Vaporized Cannabis in Healthy Adults Who Infrequently Use Cannabis, 2018. Double-blind crossover clinical trial from Johns Hopkins.
- Abrams and colleagues, Vaporization as a Smokeless Cannabis Delivery System, 2007. Small device-specific pilot study.
- Pomahacova, Van der Kooy, and Verpoorte, 2009. Laboratory comparison of cannabis smoke and vapor composition at different temperatures.
Editorial review: Reviewed by Chris Garcia, Owner and CEO of Plenny. Last reviewed August 14, 2026. This page is educational and does not recommend an inhalation method or individualized dose.
Chris Garcia, Owner and CEO
August 27, 2026
How this page is prepared: Plenny compares available product details and batch COAs with linked primary and reputable sources. General strain, flavor, and effect descriptions are not guarantees.
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