Marijuana (Cannabis):

Inhalation: Smoking vs Vaping

Smoked cannabis refers to direct combustion of the cannabis plant and inhalation of the smoke from combustion. Vaporization is a method of inhaling  cannabis vaporized by heat without flame which decreases the number of toxic byproducts produced by combustion.


Understanding Dosing with Smoking and Vaping

Marijuana Dosing –Flower vs Pharmaceutical Products

Marijuana (Cannabis) – Dosing


Links to other Pertinent Educational Pages:

Links to ALL Marijuana Educational Pages

Use and Dosing

Marijuana (Cannabis) – Inhalation: Smoking vs Vaping

Marijuana (Cannabis) – Oral Use (Edibles)

Marijuana *Cannabis) – Topicals

Marijuana (Cannabis) – Dosing

Marijuana (Cannabis) – Dosing: “Pot” vs Pharmaceutical Products



The medical information on this site is provided as a resource for information only, and is not to be used or relied upon for any diagnostic or treatment purposes and is not intended to create any patient-physician relationship.  Readers are advised to seek professional guidance regarding the diagnosis and treatment of their medical concerns.


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Inhalation: Smoking vs Vaping

There are a number of differences between smoking and vaping marijuana (cannabis). Although smoking raw marijuana has the advantage of being less expensive, with further evaluation vaping is generally recommended over smoking.



  1. Most common route of administration, but not recommended (joints, bongs, pipes, etc.)
  2. Combustion heats cannabis to 600–900 °C (1100-1650 °F) produces toxic biproducts including: tar, PAH (polycyclic aromatic hydrocarbons), carbon monoxide (CO) and ammonia (NH3).
  3. Chronic use associated with respiratory symptoms (bronchitis, cough, phlegm), but not lung cancer nor COPD (if cannabis only). Mixing cannabis with tobacco increases respiratory/cancer risk
  4. 30–50% of cannabis is lost to ‘side-stream’ smoke



  1. Vaping heats cannabis to 160–230 °C. (320–450 °F) This reduces carbon monoxide (CO) exposure but does not completely eliminate exposure to PAH  (polycyclic aromatic hydrocarbons).
  2. Vaporization produces significantly less other harmful byproducts vs. smoking.
  3. Reduced pulmonary symptoms are reported compared to smoking.
  4. Oven-style Vaporizers for marijuana flower (available, but not sold in LA pharmacies) Vaporizers designed for use with loose marijuana flower have a small “oven” chamber that allows for loading up to 0.3 gms of flower to be vaped. The vaporizer heats the flower to 360 – 420 F over about 45 seconds until it is ready for inhalation. There are multiple brands and models available in vape shops and on the internet but they are not sold in LA marijuana pharmacies. One popular oven-style vaporizer is the Pax 2 which sells for $150 on the manufacturer’s website.
  5. As a rule of thumb, loading 0.3 gm of flower rated at 18% THC would allow for a maximum delivery of up to approximately 50 mg THC, less 30–50% of cannabis lost to ‘side-stream’ smoke, equating to a THC dose of about 25-30 mg THC.


Smoking/Vaping Effect

  1. Smoking/Vaping onset of maximum effect:  5–10 minutes
  2. Smoking/Vaping duration of effect: 2-4 hours
  3. Rapid action, advantage for acute or episodic symptoms (nausea/pain).



Oral Ingestion vs Inhalation

  1. Juicing cannabis or making cannabis teas from plant marijuana do not allow for adequate decarboxylation of THCA and CBDA,  the relatively inactive components rhat are found in the  raw plant that require heat to be converted to the more active forms, THC and CBD.
  2. Oils, capsules and other oral routes have become increasingly popular due to convenience and accuracy of dosing.
  3. Edibles (brownies/cookies) are often more difficult to dose and lead to accidental ingestions, especially children. There are a growing number of reports of accidental overdosing with edidles leading to extreme side effects including panic attacks, paranoia and psychotic-like symptoms. See: Oral Use (Edibles)
  4. Tinctures and lozenges designed to be held in the mouth or under the tongue to allow for more rapid absorption into the blood through the oral mucosa have intermediate onset between inhaled and oral but have limited research. See: Tinctures
  5. Oral onset of maximum effect: 60-180 minutes
  6. Oral duration: 6-8 hours
  7. Less odor, convenient and discrete, advantageous for chronic disease/ symptoms but titrating dosing is more difficult.


Oromucosal (Sublingual & Buccal)

  1. Oromucosal onset of maximum effect: 15–45 minutes
  2. Oromucosal duration of effect: 6-8 hours



Harm Reduction:

  1. Do not operate dangerous equipment or perform potentially dangerous activities after use
  2. Do not combine with tobacco
  3. Do not use with alcohol, opioids, or sedating drugs
  4. Keep cannabis safely stored under lock and key
  5. The maximum recommended dose is 1 inhalation 4 times per day (approximately 400 mg per day) of dried cannabis containing up to 9% THC.


Cannabis users should be advised not to drive for at least:

    1. Three to four (3 to 4) hours after smoking
    2. Six (6) hours after oral ingestion
    3. Eight (8) hours if they experience a subjective “high”


Cautions Associated with Inhalation

Inhaled cannabis should be used with caution in:

  1. Patients who smoke tobacco
  2. Patients who are at increased risk of cardiovascular disease
  3. Patients who have anxiety or mood disorders
  4. Patients who are taking high doses of opioids or benzodiazepines


The principle reason for caution with inhaled drugs is that in general inhaled drugs have more immediate and higher blood levels associated with this means of administration. Therefore, especially in the case of cannabis-based products, there is a greater risk for side effects, especially cognitive dysfunction such as sedation, confusion and impaired decision making and problem solving. Also, with inhaled medications there is greater difficulty in accurately determining dosage unless provided with inhaler devices designed to deliver specific amounts of drug. Additionally, due to the heightened and immediacy of drug-induced effect associated with inhalation, there is an increased risk for abuse and addiction compared with other means of administration such as sublingual, buccal or oral.


Dosing Considerations with Raw Marijuana


Marijuana (Cannabis) – Dosing

Marijuana (Cannabis) – Dosing: “Pot” vs. Pharmaceutical Products


  1. The determination of dosing is one of the major stumbling blocks in the study of medical marijuana. This is because marijuana, a plant, varies widely in the amount and ratios of the pharmacologically active constituents present depending on a multitude of variables. Depending on the plant there may be over 100 pharmacologically active constituents all of which vary depending on the genetics of the plant, the conditions in which the plant was grown, how and when it was harvested and other variables. As such there is a huge variability in the potency and expected effects between different plants.
  2. As noted above, the major pharmacologically active constituents found in marijuana are the cannabinoids THC and cannabidiol (CBD). The average contents of THC and CBD in dried plant preparations of marijuana confiscated from 1993 to 2008 in the United States were 4.5 and 0.4, respectively, although these contents vary widely. In the last decade these percentages have increased in different strains to more than 5-10 times as potent.
  3. In addition to the cannabinoids there are other constituents found in marijuana that may contribute significantly to the pharmacologic effects. Include in these other constituents are the terpenes, fragrant chemicals that often give the notable scents associated with marijuana leaves and flowers. Their pharmacologic roles are currently being studied.
  4. It is also believed there may be an “entourage” effect in which the synergistic actions of the many pharmacologic agents in marijuana contribute to the overall effects, both therapeutic and adverse. Thus it may not be the amount of THC and/or CBD that singularly determine the pharmacologic effects but the overall combination and ratios of the many pharmacologic constituents present in the plants.



The Canadian Experience

In Canada, the medical indications for inhaled marijuana (dried plant) are limited to those patients with severe neuropathic (nerve) pain who have experienced inadequate pain relief or intolerable side effects with trials of standard treatments including: NSAIDs, anticonvulsants (gabapentin (Neurontin) or pregabalin (Lyrica), antidepressants (duloxetine/Cymbalta) and amitriptyline/Elavil, or opioids (tramadol, hydrocodone etc.) and have not responded to adequate trials of pharmaceutical cannabinoids.


Canadian Guidelines Contraindicating Use of Inhaled Cannabis Products:

Inhaled cannabis is contraindicated in:  

  1. Patients who are 25 years of age or younger
  2. Patients who have a current, past, or strong family history of psychosis
  3. Patients who have a current or past cannabis use disorder (marijuana addiction)
  4. Patients who have a current substance use disorder (chemical or behavioral)
  5. Patients who have cardiovascular or respiratory disease
  6. Patients who are pregnant or planning to become pregnant



Canadian Dosing Guidelines – Inhaled Cannabis (Smoked and Vaped)

Based on these Canadian guidelines, when smoking is advised (which it is generally not), initial dosing recommendations for smoked marijuana are usually for small amounts of lower-potency marijuana. For example, the starting recommended dosing is 1 inhalation of a “joint” (with up to a 9% THC maximum) once per day. This can be increased to a maximum recommended dose of 1 inhalation 4 times a day, resulting in approximately half a “joint” per day (or up to 400 mg). People should not operate dangerous equipment or perform potentially dangerous activities after use. This includes no driving for a minimum of 3 to 4 hours after inhaled medical marijuana, 6 hours after oral ingestion, and for at least 8 hours if they experience a subjective “high.”


Higher doses are sometimes used. It should be noted that if patients use a 5 gram (current maximum) dose of 15% THC, this represents approximately a 20 times higher dose than the recommended 400 mg of 9% THC. Higher doses, especially at this level are associated with significantly higher risk of adverse side effects (see below). In marijuana resin, which is commonly referred to as hash or hashish, the mean contents of THC, CBD, and CBN are 14.1, 2.5, and 1.9%, respectively. Other commercial products including oils and edibles may contain higher potencies still.



National Academy of Sciences

The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations for Research

This website appears to be good resource for exploring medical marijuana.



  1. Simplified guideline for prescribing medical cannabinoids in primary care – Canadian Family Physician – 2018
  2. Physician Recommendation of Medical Cannabis Guidelines Calif Medical Assoc – 2011
  3. Prescribing smoked cannabis for chronic noncancer pain. Preliminary recommendationsCanadian Family Physician – 2014


Medical Marijuana – Vaping

  1. Drug Vaping – From the Dangers of Misuse to New Therapeutic Devices – 2016
  2. Drug vaping applied to cannabis – Is “Cannavaping” a therapeutic alternative to marijuana? – 2016
  3. Toking, Vaping, and Eating for Health or Fun: Marijuana Use Patterns in Adults, U.S., 2014. – PubMed – NCBI



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