Research Outline

Risks Associated with Vaping Marijuana


To determine the health risks associated with vaping marijuana bud (not oil) and whether it is considered less risky than smoking marijuana bud, based on current scientific evidence.

Early Findings

Vaping Marijuana

  • A study from John Hopkins Behavioral Pharmacology Research Unit found that vaping a similar amount of flower has a stronger intensity than smoking the same amount of the flower. Throughout the study, participants vaped or smoked various amounts of the cannabis flower. They were all monitored for impairment. Their heart rates, blood pressure, and blood were monitored throughout the study.
  • Regardless of how participants rapidly inhaled 25mg of THC, they got extremely high; several participants tripped at this dose. At this dose, "participants experienced bloodshot dry eyes, pounding heart rate, paranoia, and an increased appetite, with the effects lasting up to eight hours.
  • The study also found that at each dose, vaping resulted in "significantly greater subjective drug effects, cognitive, psychomotor impairment, and higher blood THC concentrations than the same doses of smoked cannabis." Those vaping made double the mistakes of those smoking on cognitive tests; they also reported more adverse effects, such as paranoia.

Effects on Lungs

  • Typically smoking the cannabis flower is more harsh on the lungs than vaping the flower. This is because smoking involves burning the flower.
  • There is very little research available on the effects of vaping cannabis flower vs smoking cannabis flower, however, the research between smoking and vaping nicotine shows that smoking has a more adverse effect on the lungs. Michael Blaha, M.D., M.P.H., director of clinical research at the Johns Hopkins Ciccarone Center for the Prevention of Heart Disease has said, that research has shown smoking to be more harmful to the lungs, but this does not mean vaping is safe. There have been 60 deaths from lung injuries associated with vaping. The CDC has identified vitamin E acetate as being the culprit. This is usually associated with also consuming THC oil.
  • Evidence is emerging that links vaping to chronic lung and cardiovascular disease.


  • There has been very little research beyond the John Hopkins study on the effects of smoking vs. vaping marijuana flower. Most of the research has concentrated on the risks of nicotine rather than marijuana. What research there is, seems to have focused on comparing smoking the flower vs. vaping oil. Spending additional time searching is unlikely to provide a significant amount of data unless we broadened the research to consider the risk of smoking nicotine vs. the risk of vaping nicotine or, alternatively, the risk of smoking marijuana v. vaping marijuana oil.