CBD vs. THC: How They Differ in Benefits, Risks and Effects

It’s easy to get confused between CBD and THC. But they’re two separate and distinct cannabinoids, which each have different effects, benefits, risks and legality. Both are naturally produced by the cannabis plant. This is why they are frequently mixed up, both are extracted from the same source. Yet more than 100 individual cannabinoids are produced by the plant. CBD and THC are the most renowned, well-studied, and popular among users. CBD or cannabidiol is commonly used to treat many health conditions like anxiety, arthritis, and inflammatory conditions. It’s non-psychoactive and available in Australia as both a prescription and over-the-counter medication. THC or tetrahydrocannabinol also has medicinal properties, particularly in treating pain, insomnia and nausea. But its primary difference is activating the cannabinoid receptors directly and more strongly which causes psychoactivity. While there are some similarities in their properties and benefits, CBD and THC are very different in their risks, side effects, legality and neurological effects. Let’s examine where and how these differences exist.

Overview of CBD and THC

CBD and THC are both produced from cannabis, The two are the most abundant cannabinoids created by the plant. They’re also the most widely known and used. In Australia, interest has grown for both. Laws have changed making CBD available in pharmacies over the counter and many other stores meaning more people are using it today. Primarily CBD is taken for its anxiety-lowering and stress-reducing effects, plus its abilities to reduce inflammation, help with sleep and assist with arthritis. THC is now also available on a prescription basis for certain conditions. It can be prescribed by doctors for medical uses such as pain or nausea treatment.

CBD is only sourced from industrial hemp. This is a subspecies of cannabis that contains little to no levels of THC. It is specifically bred to contain less than 0.2% THC. Most CBD oil is produced from this type of hemp to limit its THC content and avoid psychoactive effects in users. THC on the other hand can be produced from medical cannabis strains that include marijuana. Medical cannabis is strictly controlled and can only be farmed commercially using a government license in Australia. As opposed to industrial hemp, marijuana is often grown to maximize THC content for medical purposes in treating patients with chronic pain or acute nausea. It will also contain a mix of other cannabinoids like CBD, CBG, or CBN in differing strengths and quantities depending on the strain and how it’s grown. 

Psychoactive Differences

Although both CBD and THC are cannabinoids, their differing effects, psychoactivity and interactions in the body are primarily due to the types of receptors they bind with, plus the strength of response they produce. THC can bind with dopamine and serotonin receptors, as well as cannabinoid receptors directly. Dopamine is a neurotransmitter responsible for reward and motivation. Because THC can increase dopamine, it has the potential to become addictive. It is also euphoric and can cause a ‘high’ because it strongly activates the cannabinoid receptors in the brain. 

Endocannabinoid and Neurotransmitter Activity

Specifically, THC interacts with the CB1 receptors found in the brain and central nervous system. When THC binds to these receptors, it activates them. The resulting neurological response can cause a ‘high’ through altering serotonin and dopamine levels. THC is more powerful than CBD and activates the cannabinoid receptors strongly, which is why its effects are far more noticeable and rapid. THC modulates neurotransmitters in the brain like dopamine and serotonin directly. In particular, it can bind to serotonin receptors and affect serotonin reuptake. Serotonin is the neurochemical responsible for mood, sleep, memory, and learning. By binding with these receptors, THC acts similarly to anti-depressants or SSRIs, enabling the release of more serotonin. This stimulates the pleasure centres of the brain, causing the release of endorphins and feelings of euphoria associated with THC. This is the ‘high’ you experience from cannabis use. It’s why THC is classified as psychoactive.

CBD has a weaker action on the CB1 and CB2 cannabinoid receptors. It doesn’t directly activate these receptors in the same way as THC. Instead, it can modulate the activity of these receptors and other neurotransmitter receptors indirectly by inhibiting the breakdown of enzymes like FAAH. It activates the endocannabinoid system and its cannabinoid receptors indirectly via this mechanism, offering a range of therapeutic effects without causing intoxication. CBD is also able to influence serotonin which explains some of its mood-promoting benefits. In addition, it can modulate the pain receptors which can help to reduce the perception of pain.

How CBD and THC Work

After being consumed and absorbed, the liver breaks down cannabinoids like CBD and THC into metabolites which are then used by the body’s cannabinoid receptors. These metabolites interact with the body’s endocannabinoid system, binding to its receptors throughout the brain and body to trigger metabolic effects. The endocannabinoid system consists of a network of enzymes and receptors throughout the body that influence mood, sleep, immunity, and metabolism. This is how both THC and CBD can provide benefits like improved mood, lower stress, and treatment for sleep issues like insomnia

How Do CBD and THC differ?

In Australia, CBD and THC differ significantly in their legality, side effects and risks, benefits, and mechanisms of action in the body.

Legality Differences

In Australia, both THC and CBD can be legally purchased for medical purposes. Both are available via doctor prescriptions, but CBD can also be purchased without a prescription from 2021. THC on the other hand can’t be bought without a prescription. This was made possible after the Therapeutic Goods Administration (TGA) rescheduled CBD from a Schedule 4 to Schedule 3 medicine. Low-dose CBD can be purchased over the counter in licensed pharmacies however availability can vary. High-strength products can also be purchased through the Special Access Scheme in Australia which requires approval to use CBD as part of a pre-approved condition. 

This came after reviews found CBD was well tolerated, therapeutically beneficial and safe to use with very minimal risks at low doses. THC on the other hand is still classed as a Schedule 4 drug in Australia. It can be prescribed as medical cannabis for certain conditions like chronic pain or insomnia by doctors but is more inaccessible to the average person. As THC carries a higher risk of harm, addiction, and side effects, wider availability is unlikely to come anytime soon in Australia. CBD on the other hand may well become fully legalized for non-prescription purchases shortly because of its safety profile and non-psychoactivity.

It is not legal to drive with THC in your system in Australia. The same laws don’t apply to CBD which is legal to drive on after consuming it. Roadside drug testing in Australia only tests for THC, while CBD is exempt from the testing protocol. These tests only look for the presence of THC, not whether an individual is impaired or not. Because of this, many users of medical cannabis will test positive for THC while driving despite having not used THC recently due to the cannabinoid having a long half-life in the body. It can take weeks or even months to break down in daily users. Even though CBD can cause drowsiness and reduced reaction time at high doses it isn’t checked for in any testing.

Side Effects and Risks Differences

THC has a much greater risk of harm and side effects than CBD. This is due to its more powerful effects and direct interactions with neurotransmitter receptors. THC’s resulting psychoactivity means it can cause and worsen mental illnesses, plus even cause psychosis in bad cases. Those with existing mental conditions like anxiety, schizophrenia and bipolar should avoid using it entirely. In contrast, CBD has minimal side effects and is safe even at very high dosages.

THC Side Effects

THC has a variety of potential side effects. The risks of these side effects occurring increase with greater usage frequency and dosages consumed. Some of these include dry mouth, motor function issues, reduced reaction speed, memory impairment, and irritability or paranoia. Chronic regular use of THC is linked to impaired memory and cognition. This can particularly become acute among teenagers and children who are exposed to THC. As THC is dopaminergic because it acts on the brain’s pleasure centres, it carries the risk of addiction. Around 1 in 10 regular users of THC are expected to develop an addiction to the cannabinoid. Addiction tends to be more common for those with depression or underlying mental conditions. CBD in contrast is non-addictive as it doesn’t have any direct interactions with dopamine or serotonin in the brain.

CBD Side Effects

CBD has weaker interactions with the neurotransmitter receptors meaning its health risks are substantially lower than those of THC. It’s been considered very safe by health bodies including the WHO. Studies have assessed the health risks of cannabidiol and found that even when using high doses daily, its side effect risks are low. It’s also non-toxic and can’t cause addiction because it doesn’t affect dopamine. When side effects are encountered they are almost always mild. Some of the side effects of CBD include dry mouth, appetite changes, upset stomach, and drowsiness. Like with THC, CBD’s side effect risks increase at high dosages.

The major risk of using CBD comes from combining it with other medications which are broken down by the liver. It can lead to the build-up of liver toxins and cause adverse reactions if taken in combination. Never mix CBD with other pharmaceutical drugs or prescriptions until you consult with your doctor. Combining medications like benzodiazepine or blood pressure medicine with CBD is potentially dangerous and could cause liver toxicity.


While both CBD and THC are generally safe to use therapeutically when dosed correctly, THC becomes more unsafe at higher dosages or strengths. It also has the potential to cause both short and long-term memory, cognition and coordination impairment. Studies have shown these effects are worse comparatively than alcohol or tobacco use. THC affects the hippocampus and areas of the brain responsible for memory, attention and learning. CBD on the other hand can be used at high dosages for long periods without any real risk of similar cognitive outcomes.

Benefits and Effects Differences

Pain Relief

CBD and THC have some crossover in benefits due to both cannabinoids interacting with the endocannabinoid system. The two cannabinoids are synergistic in many ways and complement each other when taken together for certain conditions. An example is pain reduction. While both CBD and THC are effective in mitigating the perception and symptoms of certain pain types such as neuropathic pain, in combination they work even better. Most pain medication using CBD is in combination with THC at a 1:1 ratio. THC is known to be more effective for chronic pain treatment but is amplified when used with CBD. Because of its potency, THC offers greater relief for acute pain and can be dosed to quickly provide symptom reduction. CBD is better for assisting with underlying inflammation that can exacerbate pain which leads to many common forms of chronic pain. Used together they offer the greatest effects and both particularly work for reducing nociception or the perception of how we feel pain. They work to reduce nerve signalling via the cannabinoid receptors, minimizing pain sensations to alleviate symptoms.

Stress and Anxiety

Both CBD and THC can lower anxiety and stress. However, these effects vary across different people. For many, THC worsens anxiety because of its psychoactivity. THC frequently worsens mental disorders in users and can cause paranoia. CBD is non-psychoactive but can still provide stress relief via the CB1 receptors in the brain. It’s more reliable for its anxiety-reducing properties. By also acting on the brain’s serotonin receptors, CBD offers anxiolytic (anxiety-lowering) benefits. For those using THC, combining it with CBD can often help to reduce or eliminate anxiety-related side effects this cannabinoid can cause. For some users, THC can help with stress, but in the long term, it tends to worsen feelings of anxiousness.

Epilepsy and Neuroprotection

A major difference between CBD and THC in benefits lies in their ability to mitigate symptoms of epilepsy. CBD has been directly shown in a range of clinical trials to offer neuroprotection and help reduce both seizure length plus severity. It is currently in use as a medication for epilepsy known as Epidiolex which targets multiple different types of epilepsy syndrome. Clinical studies have displayed immense potential for CBD in treating children who have epilepsy or seizure disorders. Today it’s already being taken by many with these conditions to help prevent seizures and reduce their impacts on their lives.


Another difference in benefits between CBD and THC relates to nausea treatment. THC is used in modern medicine to help combat nausea symptoms. It’s a recommended method to treat both acute and chronic nausea arising from adverse reactions to medication, radiotherapy, and cancer treatments. CBD doesn’t have the same capacity to mitigate nausea. Today THC is employed in drugs such as Marinol that are targeted towards users undergoing cancer treatments involving radiation. They help users in building back their appetite, mitigate pain and provide mental relief.

Key Differences in Benefits

To recap, CBD is more widely used and effective at treating inflammation, anxiety, epilepsy, and some types of pain and assisting with arthritis, IBS, plus sleep. Unlike THC, it won’t exacerbate mental illnesses or conditions like depression. The opposite is true, with CBD displaying antidepressant and anxiolytic qualities. It helps with headaches, seizures and other neurological conditions such as PTSD and insomnia. THC, in contrast, is mostly used to help fight nausea and appetite problems in cancer patients, treat glaucoma, for pain mitigation as an opioid alternative, plus assist with issues like insomnia or chronic stress in some users.

CBD vs. THC Products

You can consume CBD or THC in many of the same ways. Both can be infused into many different consumable products including oils, tinctures, vapes, edibles, and more. Usually, CBD is taken as an oil, while THC is generally ingested by smoking or vaping by most users. It is up to your personal preferences and tastes as to how you take either of these cannabinoids. Once they enter the body, both are absorbed into the bloodstream as CBD or THC molecules and subsequently transported to the liver. We advise against smoking or vaping because of the toxicity this poses towards the lungs. 

Many users prefer to apply CBD topically via creams to target inflammation or pain in particular body regions such as the knees with arthritis. Sprays, sublingual, capsules and other options are also common today. You can even find THC and CBD in drinks or candies frequently such as CBD gummies. Different CBD products also contain distinct mixtures of cannabinoids.

Choosing Products

Because CBD and THC have entirely different characteristics, effects and risks, the decision to choose one over the other is of high importance. Generally, you have the choice of buying pure CBD products, pure THC products or those which combine CBD and THC in different quantities. Deciding on which of these options makes the most sense for your health goals or condition will require research and consultation with your doctor. Note that in Australia you can only obtain products containing THC via prescription. CBD products can be purchased in many pharmacies over the counter but will not contain any THC.

An advantage of products containing both cannabinoids is that CBD and THC can be synergistic and work better together when combatting certain conditions like pain. The anxiolytic qualities of CBD also assist in mitigating some of the psychoactive effects of THC that can lead to anxiety and paranoia. In combination, their therapeutic effects can be amplified while lowering the downside side effects of THC.


The main advantages of using CBD without THC are:

  • Non-psychoactive: CBD doesn’t activate the cannabinoid and serotonin receptors directly, meaning it won’t get you “high” or intoxicated. This is also useful because CBD doesn’t get drug tested or create risks in the workplace or driving tests. It’s more suitable for those who have mental illnesses and can’t use THC.
  • Minimal Side Effects: CBD is better tolerated than THC, not as powerful and has less impactful side effects. In particular, it doesn’t have the same risk level for mental harm or psychosis as THC because of its psychoactivity. 
  • Legal Status: CBD is more widely accepted and legally available than THC in Australia and other regions because it is non-intoxicating. In Australia, it can be purchased in pharmacies over the counter without a prescription, while THC is more strictly controlled and always requires a prescription.

CBD is generally better used than products containing THC for:

  • Anxiety and Stress: CBD is non-psychoactive meaning it’s better suited for anxiety disorders. THC can worsen anxiety in many people or cause long-term mental health problems even if it solves short-term stress. CBD is being used for many types of anxiety including generalised, social and even some phobias.
  • Epilepsy: CBD is an effective treatment for epilepsy and is already being used in clinically approved medicines for multiple types of epilepsy, including Dravet and Lennox-Gastaut syndrome.
  • Anti-Inflammatory: CBD has greater anti-inflammatory properties than THC. It’s better suited to fight inflammatory conditions like IBS, arthritis or endometriosis.


Pure THC products that contain little to no other cannabinoids can be more useful than CBD products in certain cases of scenarios:

  • Pain Relief: THC is more effective for pain reduction than CBD. It can be used as an alternative to stronger pharmaceutical painkillers in some cases. It’s used today for nerve and cancer pain in particular, but many find it useful for symptoms of chronic pain.
  • Nausea and Vomiting: unlike CBD, THC is very powerful at lowering nausea and limiting the impact of it in people with chronic health problems like cancer who are undergoing chemotherapy. It helps lower feelings of stomach upset, vomiting, illness and dizziness to improve day-to-day quality of life.
  • Appetite Stimulation: THC is known to increase appetite and promote eating. This is useful in combating appetite loss from certain health conditions, anorexia, and eating disorders and in treating cancer patients who have nausea but need to eat.
  • Sleep: Some people find THC helps them get to sleep. It can help with insomnia but also reduces REM stage sleep so shouldn’t be used long-term. It aids many in calming down before bed to rest more easily.

THC and CBD Combined

Combining CBD and THC can carry advantages over either cannabinoid on its own. In particular, these types of products are great for:

  • Enhanced Therapeutic Effects: When used together, CBD and THC can have amplified effects in areas like pain reduction, and nausea alleviation, plus in supporting better sleep. This is particularly acute when they’re combined with terpenes that elevate cannabinoid absorption. For example, 1:1 ratios of THC and CBD are better at treating chronic pain, neuropathic pain, or pain associated with conditions like arthritis.
  • Balancing Effects: CBD can help balance out the heightened anxiety and adverse side effects of THC. It calms the mind and helps avoid negative thought patterns that can cause bad experiences with THC.
  • Personalized Treatment: Combining CBD and THC allows for more precise customization of the treatment to address specific symptoms or conditions. The ratio of CBD or THC can be increased or decreased to offer a distinct, targeted method of optimising the cannabinoid mix used in the treatment.
  • Reduced Psychoactivity: The presence of CBD may reduce the intensity of the psychoactive effects of THC, making it more tolerable for individuals who are sensitive to THC’s intoxicating properties.

Outside of CBD and THC content, you can find three types of cannabinoid formulations in the market, isolate, broad spectrum and full spectrum. Choosing the type that best meets your needs is important to maximize benefits and results for your condition. Isolate products only contain the CBD or THC cannabinoid, full-spectrum contains all cannabinoids from cannabis in different quantities, while broad-spectrum products will contain a mix of limited, target cannabinoids such as CBG and CBN. It’s worth weighing each option here when considering a product to buy. Each will have pros and cons but a major factor to know is terpene content. Isolate products contain no terpenes which improve the effects of CBD, THC and other cannabinoids. This is called the entourage effect and can only be realised by using full or broad-spectrum products. It improves the overall efficacy of the product and makes it higher potency.

Does CBD Oil Have THC in it?

While CBD and THC are different, it is possible that your CBD product also contains THC. Most CBD products are produced in similar locations and even with the same equipment as products that contain THC. This creates a risk of cross-contamination with THC in your CBD oil. It is even possible that the extraction method used for the CBD was not thorough enough and resulted in THC making its way into the final product. This is fairly common amongst CBD oils extracted using solvents like ethanol which are less effective at removing THC than using a supercritical CO2 extraction. Low-quality CBD extracted with solvents has a much higher risk of containing THC than high-purity CO2 extract oil.

Full-Spectrum CBD and THC

If you’re purchasing a full-spectrum CBD oil, there is a higher risk it contains some level of THC in it due to it being less refined. In Australia, this type of oil is permitted to contain up to 0.35% THC. Full-spectrum CBD oil is much less processed than isolated CBD oil. During extraction, much of the hemp plant matter and minor cannabinoids like CBG and CBN are retained in the final product. Retaining a higher concentration of the ‘full-spectrum’ of cannabinoids in hemp also means a higher concentration of THC. Many of these products in the market contain much greater THC levels than advertised. 

Mislabelling of CBD Products

A major problem in the CBD industry is the lack of regulation on products. This particularly applies to advertising and product labelling. Accidentally mislabelling CBD products is common. Many pure CBD isolate oils which are meant to contain 0% THC frequently contain much greater THC concentrations. Often providers don’t even lab test their CBD product to assess its cannabinoid concentrations and understand whether it contains THC or not. Always look for objective 3rd party lab tests from a provider to get confidence your product does not contain THC.


Although CBD and THC are produced by the same plant, they differ distinctly in their neurological effects, benefits, legality, risks, and side effects. Both have their place in assisting people with their health and treating a range of different health conditions. CBD is safer to use and has less side effects. It’s better taken for anxiety, inflammation, arthritis and epilepsy. Plus it can be used to assist with sleep, stress and general wellbeing. CBD is not psychoactive and won’t risk exacerbating mental illness. THC can be applied to certain conditions like chronic pain, nausea and appetite problems in the right circumstances but has higher side effect risks and addiction potential. If you’re considering either cannabinoid for your health, check in with your doctor first. Ensure you avoid any risks such as adverse interactions with existing medications.