Canadian Cannabis - Cannabis in Canada
March 27, 2019

The Basics of Medical Cannabis Oils in 2019

Mel Perron
10 min

Medical cannabis has been legal in Canada for over a decade, but the revised and newly enforced  Cannabis Act on October 17, 2018, has brought even more towards the widening community of cannabis users.

As interest in cannabis on both a medical and recreational scale ramps up, it is important for medical cannabis patients to understand how to consume their cannabis safely and efficiently. Knowing how the current laws affect their own prescriptions and purchases, understanding how to dissect a label, being able to correctly convert doses from dried cannabis to oils, and grasping the concept of equivalency factors are a few of the most important skills for medical cannabis users to master.

New Legal Considerations

Despite Canada’s major legal shift in cannabis-related regulation, laws surrounding medical cannabis have not changed since 2016 and the implementation of Access to Cannabis for Medical Purposes Regulations (ACMPR).

However, the Cannabis Act brought with it a new regulation stating that all cannabis (including medical cannabis) is subject to excise tax. While medical cannabis was already unlike other prescription medications in that it was subject to both provincial and federal sales taxes, medical cannabis users are now also forced to consider additional taxation passed along with the legalization of recreational cannabis.

This excise tax is calculated at $1 per gram of cannabis or 10% of its retail price, whichever is highest.

Examining the Labels

Understanding integral information such as the potency of medical cannabis all starts with the label.

Perhaps some of the most critical pieces of information found on any medical cannabis packaging are the percentages of both THC and CBD. For newer cannabis users, these numbers and letters may seem like little more than alphabet soup.

Before diving into the specifics of calculation and dosing, let’s talk cannabinoids.


Cannabis plants contain hundreds of cannabinoid compounds, but THC and CBD are thus far the most discussed and thoroughly understood. THC, short for tetrahydrocannabinol, is the substance in cannabis responsible for the euphoric high experienced by cannabis users. CBD, or cannabidiol, is the substance in cannabis products associated with numerous health benefits from anxiety relief to treatment for refractory seizures.

Over the years, cannabis growers have selectively bred particular strains to contain desired amounts of THC, CBD, or both—that’s where the percentages listed on cannabis packaging come in.

Percentages Explained

THC-dominant cannabis strains with a high percentage of THC and a low percentage of CBD are invaluable to many cannabis users seeking relief from chronic pain.

A cannabis strain labeled with a low THC percentage and a high CBD composition, on the other hand, won’t lead to a feeling of being intoxicated, but it could do wonders for inflammatory pain, anxiety, sleep problems, or other medical conditions.

Some strains contain roughly equal amounts of THC and CBD, which some consider the “best of both worlds.” Neither one of these prominent cannabinoids should be considered better than the other (that would be like comparing apples and oranges), and the varying percentages do not indicate the “quality” of a strain. Instead, THC and CBD simply provide different advantages which can be utilized in varying combinations depending on the needs of each medical cannabis patient.

A Note about Actual versus Potential Potencies

While this aside is less relevant for users of cannabis oils, medical cannabis patients may still find value in understanding the distinction between the actual and potential percentages sometimes included on their cannabis labels.

Health Canada requires both the potential and actual amounts of THC and CBD to be included when labeling a strain of dried cannabis. The “actual” percentage denotes the current amount of THC and CBD in the strain prior to the decarboxylation of these cannabinoids during smoking or vaporizing.

Decarboxylation occurs when the cannabis is heated, allowing its cannabinoid compounds to activate and do their work in the human body.

The “potential” THC and CBD levels refer to the percentages of these cannabinoids which will be present after activating the cannabinoids via heating and subsequent decarboxylation. Therefore, it’s the potential content that is more relevant, allowing medical cannabis users to assess a strain’s potency.

Those who use only cannabis oils, however, will not encounter these two separate measurements since cannabis oils have been previously decarboxylated and are ready for immediate oral consumption.

From Percentages to Volume

Only a single equation is necessary to convert these THC and CBD percentages to a more tangible measurement. By converting the percentage to the coinciding decimal and multiplying this decimal by the total volume of oil, users can determine the number of milliliters of THC, CBD, or both in their purchased cannabis oils.

For example, if a 50 mL bottle of cannabis oil stated that it contained 20% THC, one only has to multiply 0.20 by 100 to determine that there are 10 mL of THC per bottle.

Equivalency Factors

But what if a medical cannabis prescription is listed in grams, rather than milliliters? Often, this is the case, which causes some confusion when dosing cannabis oils.

As a result, other critical dosing information necessary to understand when purchasing and using medical cannabis is the concept of equivalency factors as described by Health Canada.

Oil products have equivalency factors which describe how one gram’s worth of a dry-weight prescription can be interpreted as a volume rather than weight. For instance, an equivalency factor of 5:1 indicates that 5 mL of a particular cannabis oil product is the same as a single gram of dry cannabis flower.

The equivalency factor can also be used to better understand THC and CBD content. Consider an example where one gram of cannabis flowers contains 100 mg of THC and one milliliter of cannabis oil contains 25 mg of THC.

In this case, the equivalency factor would be 1:4. If a prescription for dried cannabis read 2 grams per day, 8 grams of oil per day would be an appropriate daily dosage.

Using Cannabis without a Prescription

Thanks to the Cannabis Act, many Canadians have a new opportunity to experiment with small quantities of cannabis and experience some medical benefit, even without a prescription from a licensed physician.

However, it’s important to keep in mind that recreational cannabis retailers in Canada are not legally permitted to give medical advice to their customers. In other words, those who choose to use cannabis for medical reasons without a prescription will not receive the crucial education necessary to understand how cannabis may benefit their health or help them to manage symptoms for particular ailments.

Final Advice

Medical cannabis users are highly encouraged to speak to their physician regarding additional questions or to double-check that their cannabis conversions are correct for appropriately calculating dosage.

It’s always better to ask questions than make dosing mistakes!

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