What is Medicinal Cannabis?

Medicinal cannabis refers to a medicine prepared from the Cannabis plant. The term medicinal is typically used to indicate that the preparation is at a pharmaceutical-grade and is suitable for prescribing by doctors here in Australia.

Some facts about cannabis

The cannabis plant has been used for centuries by many different societies around the world.

  • Contrary to the modern usage for recreational purposes, much of its historical use has been as a herbal medicine for different ailments.
  • Some of the known usages of the plant have included for pain, such as joint aches and migraines, to helping with au sea and improving appetite, or for gut disorders such as diarrhoea.

There are also some common known side effects attributed to cannabis:

  • Whilst people have sought to feel ‘high’ or euphoric in recreational use, more unpleasant side effects are also possible including intoxication, nausea, dizziness, dry mouth. At higher levels or overuse, it can even lead to hallucinations or paranoia.
  • However, medicinal cannabis is safer to use than raw cannabis – we’ll explain why this is below in “How is medicinal cannabis different?”.

You may have heard of people talking about different ‘strains’ of cannabis. These usually refer to specific groups of plants that have been cultivated over time to have different traits. What may be surprising to you is that these are all in fact, plants of the same species – Cannabis sativa!

  • The most well-known compounds in Cannabis sativa are tetrahydrocannabinol and cannabidiol, or THC and CBD for short.
  • Different ‘strains’ contain different levels of these cannabinoids as well as other compounds, but they are still all 3 considered the same species of plant. For example, some people refer to sub-groups of this plant as ‘Sativa’ or ‘Indica’ which sometimes refers to plants high in THC or CBD respectively (however these ‘strains’ are still the same species).
  • In fact, hemp, a plant that is commonly used industrially for its fibre, is actually the same species as well, Cannabis sativa. However, it has usually been bred to contain low or no THC and may or may not have CBD.

Colloquially, people sometimes refer to oil made from cannabis as ‘CBD oil’. Whilst strictly speaking ‘CBD oil’ refers to products that mostly contains cannabidiol, sometimes this term is used interchangeably to mean ‘cannabis oil’ (or any oil with active ingredients from the cannabis plant in general).

  • Hemp can also contain CBD. In Australia however, for a plant to be classified as ‘hemp’, it has to contain very low levels of CBD Oil – otherwise, it is classified as Cannabis (which has its own regulations). For this reason, taking ‘hemp oil’ is different than taking ‘CBD oil’, as any legal hemp oil that you can purchase in Australia (or hemp seed oil) can’t have any
    significant levels of CBD or other cannabinoids.

How is Medicinal Cannabis different?

As you can see, although there are many potential benefits with this plant, there are can be some possible downsides as well. People have long sought to find out how the different parts of the plant work, and to see if different parts can help with different symptoms.

So far, there have been over 500 different compounds identified in the plant.

Most compounds aren’t unique to cannabis and can be found in many other plants. However, there are a group of chemicals called cannabinoids that are distinctive in this plant and are thought to play important roles in the effects it produces. Of these cannabinoids, the most prominent and widely studied are (delta-9) tetrahydrocannabinol and cannabidiol. These are the ones we came across previously – THC and CBD Oil.

As you can imagine there are much fewer complications when only 1 or 2 active ingredients are used, rather than all 500+! Also, many of the effects (both beneficial and detrimental) of the other plant compounds aren’t well documented at present. For these reasons, medicinal cannabis with just one or two active ingredients are more commonly prescribed and are preferred by most people.

Another common group of compounds found in cannabis are terpenes.

Terpenes aren’t unique to cannabis, and can be found in many other plants such as citrus, hops, pepper, and many others. These terpenes are usually responsible for the smell and fragrance of many plants, including cannabis. However, terpenes can also lead to some cannabis preparations having a strong smell or taste that may take some time getting used to. Interestingly, most of the differences between ‘strains’ of cannabis are due to differences in their terpene profile. For some patients though, full spectrum preferred?


Another important difference between prescribed cannabis and recreational cannabis lies in the amount of THC contained in each

In general, there are lower concentrations of THC in medicinal cannabis products

These two compounds, THC and CBD Oil, are the main cannabinoids and active ingredients used for most prescribed medicinal cannabis these days in Australia.

  • Medicinal cannabis usually contains different ratios of these two main cannabinoids, which can be used individually or in combination. Altering the balance between these two cannabinoids can enable finding the right medication for each patient, that maximises effectiveness and minimises side effects.
  • Besides there being more extensive research available for these two cannabinoids, another benefit to using these, either individually or in combination, is that they provide a more consistent treatment effect for patients.
  • Medical use also often indicates THC usage at lower daily levels – most patients don’t require very high levels of THC for the medication to be effective for them.
  • As high levels of THC seems to be more frequently responsible for side effects, treatment with prescription cannabis as a whole tends to be very well tolerated and does not frequently cause side effects.

Medicinal cannabis is often produced as an ingestible oil dose form

  • Oil is sometimes preferred because it is very stable, keeps for a long time and is easier to make small adjustments with dose with. This is especially important for people who are first starting this medication and are trying to work out the best dose for them.
  • Oils are preferred to forms such as smoking, as there are potential harm in inhaling smoke and products of combustion.
  • Another benefit for ingested oils is that the effects of each dose tend to last longer for example, compared to smoking. Typically, oil based medication may last 6-10 hours after each dose,
    compared with only 2-3 hours with a smoked form.
  • Many ‘cannabis oil’ preparations contain active ingredients (THC and/or CBD) dissolved into a carrier oil.

These carrier oils vary by the manufacturers and can be made from various sources such as grapeseed, palm, coconut, sunflower, MCT (medium-chain triglyceride – made from other oils), etc

Note: If you have allergies that you know of, especially if it involves some of these ingredients, it is best to check with your doctor or directly with the manufacturer of the medication you are prescribed – as the carrier in cannabis oil made by each manufacturer may change over time.


THC has for long been the poster child of cannabis, but science is now pushing CBD Oil to the limelight because it offers similar therapeutic benefits without the intoxication that CBD gives. We cannot confidently pick a winner between the two, so we will discuss each in detail and let you decide which suits your needs.

What Are Cannabinoids?

Cannabis has a number of compounds which include: cannabinoids, terpenes, flavonoids and other nutrients. There are over 100 cannabinoids present in the cannabis plant, however, only a handful has been investigated. Delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are the most studied of the cannabinoids. Cannabinoids interact with the body’s endocannabinoid system to help in supporting homeostasis. The endocannabinoid system is a signaling system composed of cannabinoid receptors, endocannabinoids and metabolic enzymes whose function is to create physiologic balance in the body. Therefore, cannabinoids more or less work in a similar way to the body’s endocannabinoids.

Cannabis synthesizes cannabinoid acids that are decarboxylated by exposure to heat so that they can produce cannabinoids. Thus THCA gives rise to THC while CBDA gives rise to CBD. Apart from THC and CBD, other cannabinoids include: Cannabigerol (CBG), Cannabidivarin (CBDV), Cannabigerivarin (CBGV), and cannabichromene (CBC).

With that background, let us delve into the differences between THC and CBD Oil.

What are the major differences between CBD Oil and THC?

1. Chemical Structure

It would surprise you to know that THC and CBD have exactly the same molecular structure: 21 carbon atoms, 30 hydrogen atoms and 2 oxygen atoms. They have a very similar molecular mass with THC having a molecular mass of 314.469 g/mol and CBD having a molecular mass of 314.464 g/mol.  The two compounds also originate from the same precursor: cannabigerolic acid which gives rise to THCA and CBDA. However, there is a slight difference in the arrangement of the atoms, and this “slight” difference accounts for the major differences seen between the two compounds.

2. How THC and CBD affect the body

Because of the chemical structure of THC, it is able to bind directly to the CB1 receptor. CBD Oil, on the other hand, does not have this ability. Because of this, THC is able to cause a change in the mental status and this may manifest as euphoria, paranoia, or delirium in excess doses. CBD interacts with the CB1 and CB2 receptors indirectly. Some studies have shown that CBD is able to reverse the psychoactive effects of THC. Therefore when combined, CBD may reduce the side effects associated with THC.

We can conclude that THC is psychoactive while CBD Oil is not. However, both compounds have stimulant properties.

3. The legality of THC and CBD

It is safe to say that the legality of cannabis is evolving around the world, but as it stands, recreational cannabis (with the ability to cause intoxication) is largely illegal around the globe. Recreational cannabis is illegal under federal law in the US. The same applies to the UK, Australia and other countries as well. Canada was the first of the G7 countries to legalize recreational cannabis.

Medicinal cannabis, on the other hand, has been legalized in many countries around the world. So what makes the difference between the two? The answer lies in hemp versus marijuana. Hemp-derived CBD contains less than 0.03% of THC and is considered legal in all the above-mentioned countries. With low levels of THC, this compound does not have the ability to cause the typical “marijuana high.” Marijuana-derived CBD Oil, on the other hand, may have high amounts of THC and is therefore considered illegal in most parts of the world.

The 2018 Farm Bill classified hemp as any other cash crop, making hemp-derived CBD legal throughout the US.

4. Medical benefits offered by THC and CBD Oil

Because of the way the two compounds interact differently with the endocannabinoid system, they provide different therapeutic benefits.

For starters, THC causes euphoria and is therefore avoided by many patients because of this effect. A report by the World Health Organization (WHO) that was released in 2017 confirmed that CBD is safe to use and has minimal side effects as a therapeutic compound. In 2018, the FDA approved a CBD based drug for the treatment of severe forms of childhood epilepsy- Epidiolex. Studies have also shown that CBD may be useful in the treatment of the following conditions:

  • Inflammation
  • Seizures
  • Nausea
  • Anxiety
  • Depression
  • Migraines
  • Psychosis

In spite of the side effects, THC offers quite a number of therapeutic benefits that can be harnessed. With the ability to bind to the CB1 receptor, THC has a great influence on the endocannabinoid system. With this, THC has been associated with treatment of the following conditions:

  • Pain
  • Lack of appetite
  • Insomnia
  • Glaucoma
  • Inflammation
  • Nausea
  • Muscle spasticity

As you may have noticed, there are a good number of similarities in the therapeutic benefits offered by the two compounds. The era of cannabis criminalization stalled the process of CBD and THC research, but in the current progressive era, we expect to see more research and clinical trials to establish the efficacy of CBD and THC in the fields of cancer, HIV and other chronic conditions.

5. The side effects caused by THC and CBD Oil

CBD is well tolerated in humans as well as animals, even in large doses. When side effects arise, they are most likely attributable to interactions with other medications. CBD interacts with the cytochrome P450 metabolic pathway and through this interaction, it is able to influence the metabolism of drugs.

THC, on the other hand, causes a number of side effects which include:

  • Dry mouth
  • Red eyes
  • Increased heart rate
  • Slower reaction time
  • Short term memory loss
  • Paranoia
  • Delirium in extreme cases

Thankfully, these side effects are never fatal.

Can CBD Oil and THC work together?

THC and CBD work together in a very beautiful and beneficial way in what is referred to as the entourage effect. A study conducted by the Hebrew University of Jerusalem was the first to highlight this effect: a full cannabis extract produces a healing effect that is more powerful and sustained. Another study also showed that patients who consumed CBD and THC together experienced fewer side effects as compared to patients who consumed THC alone. In a nutshell, the whole is greater than the sum of parts.