The cannabis sativa plant contains over 120 chemical components, but there are two in particular that you hear about in regards to cannabis, weed, marijuana and hash - CBD and THC. As Australia’s attitudes towards cannabis continue to develop, more people are seeking information about the plant and its effects - including understanding how CBD and THC interact with our own chemical processes. Let’s learn about the similarities and differences between CBD and THC.

How are CBD and THC similar?

CBD (cannabidiol) and THC (tetrahydrocannabinol) are the two most prominent chemical components found in the cannabis plant. Both compounds react with our endocannabinoid system - a bodily function that helps us regulate sleep, mood, stress and appetite, all of which are affected when cannabis is absorbed into the bloodstream. THC and CBD also share chemical similarities. In fact, their molecular structure is made up of the exact same components - 21 carbon atoms, 30 hydrogen atoms, and 2 oxygen atoms. 

Furthermore, because they both influence the same system they also share a lot of the same medicinal benefits. THC and CBD’s ability to slow the central nervous system’s communication with the body make both components a naturally good pain remedy, and also help counter symptoms of anxiety. 

Lastly, both THC and CBD are stored in the body’s fat cells, meaning that they are detectable in the body days or even weeks after use. As a result, both components can be detected on a drug test. It should be noted, however, that not all tests are able to detect CBD, but CBD-specific tests do exist. THC is accounted for in most standard drug tests and will likely show up on a screening if used. 

How are CBD and THC different?

Although they share the same chemical structure, the way the atoms are arranged in the compound differ - this is what causes CBD and THC to react to the body in different ways. The most notable way that the two components vary is in their psychoactive effects - CBD does not produce a ‘high’, whereas THC does because it engages the part of the brain that makes you feel intoxicated. Also, despite the fact they both react with the endocannabinoid system, they interact with it in different ways which means they can be used to treat different conditions. This is where medicinal cannabis comes in. 

When medically prescribed, CBD can be used to treat:

  • Seizures
  • Inflammation
  • Pain
  • Psychosis and mental disorders
  • Nausea
  • Irritable bowel syndrome (IBS) 
  • Migraines 
  • Depression
  • Anxiety

Whereas THC can be used to treat:

  • Pain
  • Muscle spasticity 
  • Glaucoma
  • Insomnia
  • Low appetite/anorexia nervosa
  • Nausea
  • Anxiety

If you want to learn more about these conditions, check out our page on conditions and symptoms treated by medicinal cannabis to learn about each condition and how medicinal cannabis can be used to treat it. As with any medication, medicinal cannabis does come with side effects which differ according to whether THC and/or CBD is present. 

Side effects that are possible for products containing CBD include:

  • Changes in appetite
  • Fatigue
  • Weight loss
  • Dizziness
  • Diarrhoea

Possible side effects for products containing THC are:

  • Increased heart rate
  • Coordination problems
  • Dry mouth 
  • Bloodshot eyes
  • Slower reaction times
  • Memory loss
  • anxiety 

Despite possible side effects, both CBD and THC have been proven to be safe when medically administered, and neither compound can result in overdose or has been directly responsible for death. If you are interested in medicinal cannabis for yourself or a loved one, check you are eligible with our Medicinal Cannabis Eligibility Test.


CBD and THC are two chemical compounds naturally found in cannabis and cannabis products. Although there are a variety of similarities and differences between CBD and THC, they can both be safely used to treat a variety of medical conditions. It’s important that users are educated on the effects of each compound so they can make the most informed decisions in regards to their health or the health of a loved one. Cannabis use in Australia is subject to state laws, so if you’re interested in a prescription for medicinal cannabis check your state’s legislation in order to ensure compliance. More information on each state’s cannabis legislation can be found here