Inhaling Cannabis: Smoking vs. Vaping

By Stacey Marie Kerr MD, Hawaiian Ethos Medical Advisor

the culture

The culture of cannabis is changing rapidly along with new and innovative ways to use this plant-based medicine. If you live in a place with legalized cannabis, you most likely have increased access to all kinds of products—cartridges, capsules, tinctures, topicals, edibles, and of course, flower. But even with so many new options, inhalation remains the most common delivery method.

There are many patients who keep a small pipe on their bed side, or take a puff in order to relieve anxiety or eat a meal. There is also no denying that medical or not, inhaling cannabis has been a core part of ‘the culture’ for decades. Joints, pipes, bongs, and the passing of these devices in a circle of friends is an experience that many have shared and think fondly of.

Why smoke? why not?

There are real benefits to inhaling cannabis. Active ingredients are readily absorbed through the lungs and into the bloodstream, and the intoxicating effects of THC are felt within minutes. This gives rapid relief for anyone needing the medicinal effects of THC. Other helpful parts of cannabis are delivered just as quickly when inhaled, so inhaling CBD, THCV, or any of the terpenes present in the plant can provide fast-acting relief as well as THC.

Smoking, however, is not as popular as it was years ago. As life-time cannabis users get older, they feel the effects of smoke in their lungs and some do not appreciate the irritation that comes with inhaling hot carbon. And as we learn about delivery methods, we find that many of the medicinal parts of the plant are lost when it is smoked. Medicinal compounds (cannabinoids and terpenes) are burned off before they reach our lungs, and the side stream smoke – that smoke that wafts off into the air – takes a significant amount of these beneficial chemicals off into the ether where it does us little good.

Even with the known downsides of smoking, the culture persists. Rapid effects are often the goal for many patients, bringing much appreciated help to uncomfortable situations. And there is something about sharing an inhaled medicine, something about taking a break to enjoy a smoke, something about the feeling of getting high while passing some herb to a friend.

 what exactly is vaping?

Enter vaporizing. An inhaled method of medicating that does not expose our lungs to smoke but maintains some of the ritualistic aspects of cannabis use. In the last 10 to 15 years, vaporizing options have slowly increased. Initially vaporizers were non-portable and had to sit on a table, but now there are a variety of portable and ‘pen’ devices available.

Some may assume it would take extremely high temperatures to vaporize cannabis – a ‘flash burn’ effect. But in reality, it is the opposite. To vaporize cannabis, we use lower temperatures that activate the medicinal compounds but stop short of burning the actual plant material. Instead of smoke, a gray-white vapor forms that may be inhaled for good effect. Terpenes are better preserved because of the lower temperature. Vapor may expand in the lungs and cause some coughing if a large hit is inhaled, but it does not irritate as smoke does and it carries very little of the hydrocarbon toxins that are delivered in smoked cannabis.

Which is strongeR?

Those who are used to smoking may say that vaping feels different. They are used to the hard come-on of a smoked joint and may miss that sensation. Instead they feel a smooth slow effect that can be just as strong, but feels different as it comes on. Because it does not hit as hard, they may assume that the effects are not as powerful as those associated with smoking. But science tells a different story.

according to science…

At the Johns Hopkins School of Medicine, scientists compared the two methods of inhalation and how each affected an individual’s functioning. They also compared blood levels of THC in all the participants. It was a well-designed and well-done study that produced some very interesting results.

Seventeen individuals who had not used cannabis for at least the last thirty days were divided into two groups and given six sessions to inhale, with a one-week washout period in between each session. They had no idea what they were inhaling each time, but it was one of three possible strengths: 0mg THC, 10mg THC, or 25mg THC. They both smoked and vaporized each of the three strains, not knowing which one they were getting during each of the six sessions.

Vapor was provided by a Volcano Medic vaporizer with a masked balloon, so no vapor was visible. Smoking was delivered with a hand-held pipe. Both types of inhalation were completed in ten-minute sessions.

the results

Subjective effects were noted – “How do you feel?” These included reports of dry mouth, dry red eyes, munchies, difficulty performing routine tasks, and paranoia. All of these effects increased with the higher dosing, and all were more significant when the cannabis was vaporized rather than smoked.  

Cognitive and psychomotor effects were tracked by having participants perform specific tasks. They were asked to do two things at once, to replicate a pattern using a keyboard, and to do simple math problems that required tracking series of numbers. Reaction times were tracked. All were affected as expected, with deficits more noticeable with higher doses, peaking between 30-60 minutes after use and in some instances, not returning to baseline for 6-8 hours. Again, the effects were more significant when cannabis was vaporized rather than smoked.  

Blood specimens were collected and measured for THC amounts present, how quickly THC levels rose, and how rapidly THC levels disappeared. The result may surprise some long-time cannabis users, because the actual amount of THC in blood was significantly higher after vaporizing cannabis than after smoking it.

10mg THC

Peak Blood Levels
Vapor   7.5 ng/ml
Smoke 3.8 ng/ml

Time to Peak Concentrations
Vapor 10 minutes
Smoke 10 minutes

Time to Return to Zero
Vapor within 3 hours
Smoke within 3 hours

These were relatively naïve cannabis users, and some participants experienced side effects. Two people vomited after inhaling 25mg of THC, one after smoking and one after vaping. One experienced hallucinations after inhaling a vaporized dose of 25mg. No one dropped out of the study.

It is interesting that blood concentrations of THC returned to normal sooner than cognitive and psychomotor skills returned to normal. This is relevant if blood tests are being considered as a way to test for impairment when driving or operating other heavy machinery, as blood levels would not be a valid method of establishing impairment.

While this study has a few limitations – narrow dosage range, infrequent cannabis users, and small sample size – it does give valuable insight into two common inhalation delivery methods used to dose cannabis.  It also leads to asking the question: Why does it feel stronger to smoke cannabis when vaping provides higher levels of THC?

so why does it feel different?

One theory is that some of the hydrocarbons in smoke have an intensifying effect on the experience. Another theory is that, since vaping does not destroy terpenes like smoking does, those preserved and beneficial chemicals smooth the high and allow a gentler but more thorough experience.  The entourage effect and the use of whole plant medicine is more efficiently taken in by our own endocannabinoid system, creating a more balanced effect.

preserving the culture, and your lungs

For patients who cannot tolerate inhalation of any kind, smoke or vapor, there are still options for rapid relief. Sublingual medicines, or medicines held and absorbed under the tongue, allow medicinal compounds to be absorbed directly into the bloodstream through the small blood vessels under the tongue. Two examples of sublingual medicines are Quick Dissolve Tablets and tinctures. It is important to note, however, that these medicines can also be taken orally for different effect.  

Vaporizing cannabis reliably provides rapid onset, more terpenes, more cannabinoids, fewer damaging side effects, and higher blood levels of THC. This is more efficient use of the medicine and healthier for our lungs. The work done at Johns Hopkins gives us evidence that vapor is slowly replacing smoke, redefining the ritual of using cannabis as medicine.