If you haven't heard of cannabidiol (CBD) by now, chances are you're living under a rock. Everyone is buzzing about it – it's being taken orally via capsules, added to drinks, gummies and baked goods or swallowed directly. It's also being inhaled through vapes or applied topically to treat skin issues. At least, it is in other parts of the world – you still can't get it legally in Australia without a prescription.
So what is it?
CBD is one of more than 100 active ingredients in the cannabis plant. It is extracted from the plant, and then diluted with a carrier oil, such as olive or coconut oil, so it can be consumed or used topically.
You're probably wondering: will CBD oil get you high?
Not according to accredited practising dietitian Bronwen Greenfield.
"CBD oil is extracted from the non-drug strains of the [cannabis] plant meaning that users do not experience the reported 'high' of its cousin compound, tetrahydrocannabinol (THC)," she says.
CBD is not a psychoactive substance, meaning it doesn't affect the way you behave, think or feel. THC is the psychoactive component of marijuana, but since CBD oil must contain at least 98 per cent cannabidiol to be legal in Australia, it can only contain the most minuscule amount of THC.
What about hemp seed oil?
While hemp seed oil and CBD oil are both from the cannabis plant, they come from different parts of the plant, and are used differently. Hemp seed oil has been around for decades and comes from the seeds of the plant. It is high in antioxidants and omegas 3 and 6, and is viewed as a superfood with high nutritional value. Since it doesn't contain any cannabinoids, such as CBD or THC, it is legal in Australia. CBD oil comes from the plant's flowers and leaves, and is mostly used for medicinal reasons. As it contains trace amounts of THC, it is classified as a drug under Australian law.
Why has CBD oil become so popular?
It has seen a surge in popularity owing to recent claims it is a strong anti-inflammatory, with a report from the World Health Organisation last year finding CBD may help successfully treat symptoms of Alzheimer's, Parkinson's, MS, chronic pain, anxiety, depression, cancer and diabetes. Sounds like a miracle, right?
Greenfield says the strongest evidence is its effectiveness in treating seizures.
A Stanford University study in 2014 found 84 per cent of children saw a reduction in the frequency of their seizures while using CBD, with 11 per cent stopping seizing entirely.
"It has since been legalised in the US and was approved four years ago by the TGA (Therapeutic Goods Administration) as a prescription-only drug in Australia for therapeutic use," says Greenfield.
"While still in its infancy, early research has suggested CBD oil can assist in relieving joint pain, reducing anxiety and depression, easing schizophrenia symptoms, inhibiting cancer progression, lowering chemotherapy-related side effects and improving skin health," Greenfield says.
CBD is most commonly used for natural pain relief, offering a safer option than opioids for those suffering from chronic pain. When applied topically it can help reduce pain and inflammation from arthritis.
"This is due to CBD's direct effects on the endocannabinoid system in the brain, where it can enhance the effect of other brain chemicals such as serotonin (the happiness hormone). This results in reduced pain perception, improved mood and anxiety or stress relief," Greenfield says.
CBD oil can be used as a natural treatment for anxiety and depression. It has been shown to help those suffering from social anxiety disorders, PTSD, insomnia, OCD and panic disorders.
CBD may provide some form of treatment to cancer, though this research remains in early stages, with most patients simply using it to relieve the side effects of chemotherapy, such as nausea and vomiting.
What's the catch?
The evidence behind many of these claims is questionable. Most research is in its early stages, with a lot of the hype around CBD coming from the media.
"It's important to remember that the studies so far have been rather small and have been done in labs or on animals, meaning the research behind its use and long-term effects is still limited," Greenfield warns.
Most of the studies so far were conducted on mice, and our bodies often react in different ways to animals. The lack of evidence in human studies means we can't be sure of effective doses.
Greenfield recommends consulting your GP first to assess if it's safe for you.
"CBD can interfere with the absorption and function of other prescription medications, so be sure to check these interactions with your pharmacist or GP," she says.
It also comes with its own side effects including dry mouth, low blood pressure, light headedness and drowsiness.
There is insufficient evidence to show if it's safe to take while pregnant or breastfeeding.
Another concern: CBD is marketed as a supplement, meaning it's not regulated as a medication would be.
"Therapeutic dosages tend to be quite high, thus it can be rather expensive," Greenfield says.
How to get it
The only way to get your hands on CBD legally in Australia is through the government-approved access pathway, the Special Access Scheme. This gives patients access to drugs that aren't approved by the Therapeutic Goods Administration.
While you can illegally purchase CBD online, there is a big difference in quality depending on the seller.
"Recent research found many CBD oils sold online had less or much more than the amount of CBD in the product indicated by the label, or even contained undeclared traces of THC.
"There are currently no regulations in place for producing, testing or labelling CBD products, so it's difficult to know what you're actually paying for," Greenfield says.