Winter 2020

Gear: Inhalation — Beyond the Joint

Amid concerns about potential health hazards associated with smoking cannabis, vaping is an increasingly popular method of administration.

Note to readers: This article was scheduled to appear in the inaugural issue of CRx; then the media started reporting more and more cases of e-cigarette, or vaping, product use–associated lung injury (EVALI). The editorial staff decided that before publishing, it should be investigated further.

Recently, the Centers for Disease Control and Prevention announced that vitamin E acetate is a chemical of concern among people with EVALI. As for the products associated with the disease, it’s become clear that most of the cases of EVALI are the result of illicit, gray-market, THC-containing vape cartridges.1 This reiterates the importance of counseling medical cannabis users to buy product only from reputable retailers who vet their vendors for quality ingredients, good manufacturing practices, and in-depth analysis of active ingredients and potential toxins.

Read on for more information about the safety and efficacy of vaping cannabis for medicinal purposes.

It’s well recognized that inhalation is the best method for delivering the benefits of cannabis to the body. However, most clinicians and medical consumers believe smoking isn’t a viable option. While there’s no clear association between cannabis smoking and lung cancer, chronic cannabis smoking often produces symptoms similar to those of chronic tobacco smoking such as cough, sputum production, shortness of breath, and wheeze.2 With advancements in cannabis vaporizing equipment, vaping rather than smoking is becoming a preferred method of administration for clinical cannabis use.

Typically, cannabis is smoked without a filter and burned at a higher temperature than that in traditional tobacco smoking; in addition, when smoking cannabis, users generally hold their breath for longer periods of time.2 Research into the harmful effects of tobacco smoke directly links inhalation of combusted materials with lung cancer and other chronic respiratory diseases.3 Thus, it’s assumed that inhaling the combusted products for cannabis smoking may be as harmful as tobacco smoking. And because many cannabis users concurrently smoke tobacco cigarettes, research into the direct effects of smoked cannabis on the lungs and respiratory system is difficult. However, with the growing legalization of cannabis and increasing usage by populations that don’t also smoke tobacco, research into the long-term respiratory effects of cannabis smoking is growing.

Until a more definitive link between cannabis smoking and lung health can be established, some clinicians worry about recommending that their clients smoke cannabis. Yet, inhalation is a fast and efficient method for delivering the beneficial phytochemicals in cannabis to the body. Therefore, clinicians are looking more closely at alternate inhalation devices, specifically vaporizers and vape pens.4,5

Vaping, of both cannabis and other concentrates, is growing in popularity.5 It’s estimated that 1 in 20 adults uses a personal vape pen, and the vaping industry is expected to develop from more than $7 billion in 2016 to $47 billion by 2025.6 When it comes to inhaling cannabis, vaping is quickly becoming one of the favored methods of administration because of its immediate effects, bioavailability, and ease of titration. According to BDS Analytics, concentrates are the most popular cannabis product in California and outsold flower in 2018 for the first the time in history.7

While the long-term respiratory health effects of vaping and e-cigarette use are unknown, it’s been suggested that vaping may reduce the symptoms associated with smoking.5 Thus, cannabis vaporizers can be considered an effective administration method for medical cannabis consumers.

As with any medical use of cannabis, the safety of vaping depends on the quality of the equipment used and the products’ purity and consistency. Because concentrates and flower aren’t heavily regulated even in places where they are legal, the final products may contain impurities or toxins and may not contain the phytocannabinoids expected. Hence, it’s imperative to choose a trusted and reliable dispensary or brand to ensure that the vaped product is pure and consistent. To get the most cannabinoids and terpenes from cannabis, look for expert growers that harvest, dry, and cure superior cannabis flower. For concentrates, the cleanest method of extraction for vaping involves using CO2 as the primary solvent. Reliable dispensaries and brands will disclose the extraction methods they use for their products. In some states, chemical analysis of flower and concentrates is either required or highly encouraged, and dispensaries should be able to provide a full profile of cannabinoids, terpenes, and any possible toxins or heavy metals in their products.

Benefits of Vaping and Inhaling
Aside from the potential respiratory benefits of vaping over smoking, there are three distinct benefits of vaping and inhaling active cannabinoids.

High Bioavailability
Bioavailability refers to how much of the cannabinoids travel into the system and how substantial their impact is on the identified condition. With most clinical cannabis treatment plans, the goal is to relieve the symptoms with as little intoxication as possible. While some patients are more willing to try edible cannabis products, these products have very low bioavailability—roughly 15%. On the other hand, inhaled cannabis has an estimated 40% to 60% bioavailability. This makes inhaling cannabinoids more systemically effective and more economical for patients because much less product (flower or concentrate) is needed for the goal effect on symptoms. However, it’s important to educate patients about how to inhale because bioavailability varies according to depth of inhalation, puff duration, and breath holding.8

Fast Medicinal Effect
With inhaled cannabis, the active ingredients enter the bloodstream directly. There’s no gut or liver involvement to slow the effects and reduce the bioavailability. Thus, inhaling cannabis is the fastest way to deliver the clinically active components of the plant. Studies show that THC metabolites are detectible in plasma within seconds after the first puff of a vaporizer, and peak plasma concentration is attained within three to 10 minutes.9 In fact, anecdotal evidence indicates that relief from pain and anxiety can occur instantaneously or within a few seconds.

Titrated Intake
Because the effects of inhaled cannabis can be felt so quickly, it’s easy to identify the dose needed to relieve symptoms. In clinical practice, patients are asked to inhale once, document relief, wait for 10 minutes, assess the effects again, and gradually increase the dose, one puff at a time, if necessary.

The Tools
Two types of vaporizers, portable and desktop, are available. Both work on the same principle: The flower or concentrate is heated, which releases the active form of cannabinoids into a vapor that can be inhaled.

Portable vaporizers often look like a pen and consist of a battery as the heat source, a mouthpiece, and a compartment for herb/flower or a space for a cartridge of concentrate. Most pens use conduction heating, which means the flower or concentrate comes in direct contact with the heat source. They heat quickly and are portable, inexpensive, and discreet. The one drawback to portable vaporizers is that there’s a risk of combustion, especially when used with flower, which may be damaging to the respiratory system.

Desktop vaporizers are larger and usually must be plugged into a power source. The heat source is convection, which means that hot air is pushed through and around the herb or concentrate to create the vapor. Thus, there’s no direct contact with the heating element and no risk for combustion; it’s considered the cleanest way to inhale cannabinoids. Desktop vaporizers come with either a bag or a whip. The bag is like a balloon that fills with vapor and can be slowly inhaled or shared. Bags usually come with a stopper that allows storage for as long as eight hours. The whip is usually a long tube or a straw attached to a vapor-holding container. Desktop vaporizers can be expensive and bulky but may deliver the best experience, especially for patients who inhale small doses of cannabis multiple times a day.

As with any clinical use of cannabis, administration and dose are personal decisions and may require experimentation. Some patients’ apprehension to try inhaled or vaporized cannabis as medicine may derive from misperceptions or cultural associations with “potheads” and “hippies.” Providing a more clinical, discreet solution, such as a desktop vaporizer or a vape pen, may help overcome their reluctance to try it.

— Bonnie Johnson, MS, RDN, is a certified food industry consultant, speaker, and certified cannabis consultant. As a consultant, she works with the food and cannabis industries to bring science-based education to health care professionals and category-changing products to market.

Editor’s Note
As with any information in this publication, this article not intended to diagnose, treat, or make personalized health recommendations. Patients should discuss any use of cannabis or other vaporized medication with their health care professionals.


1. Outbreak of lung injury associated with e-cigarette use, or vaping. Updated December 31, 2019. Accessed November 22, 2019.

2. Ribeiro L, Ind P. Marijuana and the lung: hysteria or cause for concern? Breathe. 2018;14(3):196-205.

3. Martinet Y, Bohadana A, Fagerström, K. Would alternate tobacco products use be better than smoking? Lung Cancer. 2006;53(1):1-4.

4. Russell C, Rueda S, Room R, et al. Routes of administration for cannabis use — basic prevalence and related health outcomes: a scoping review and synthesis. Int J Drug Policy. 2018;52:87-96.

5. Tashkin DP. How beneficial is vaping cannabis to respiratory health compared to smoking? Addiction. 2015;110:1706-1707.

6. Surging vape market propels smart brands growth. PR Newswire website. Published May 8, 2019. Accessed July 18, 2019.

7. The 2018 California cannabis marketplace in review. BDS Analytics website. Published February 18, 2019. Accessed July 18, 2019.

8. Sharma P, Murthy P, Bharath M. Chemistry, metabolism and toxicology of cannabis: clinical implications. Iran J Psychiatry. 2012;7(4):149-156.

9. Huestis MA. Pharmacokinetics and metabolism of the plant cannabinoids, delta9-tetrahydrocannabinol, cannabidiol and cannabinol. Handb Exp Pharmacol. 2005;(168):657-690.


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