The actor was first diagnosed with breast cancer in 1992 and privately overcame another bout in 2013.
In 2017, Newton-John was diagnosed for a third time and is currently in the midst of treatment for stage four breast cancer.
While doctors say the 70-year-old’s condition is incurable, it can be managed through treatment, and Newton-John says she has decided to use “everything she can” to get stronger.
Speaking to People magazine about her diagnosis, the Grease star revealed that she recently turned to cannabis to help her cope with the pain she experiences as a result of the cancer.
The English-born, Australian-raised star said that although she had used the drug recreationally a few times when she was younger, she was nervous about taking it at first.
“It has helped incredibly with pain maintenance and sleep,” Newton-John said.
“It’s an amazing plant, a maligned plant, but it’s helping so many people.”
According to Macmillan Cancer Support, it is unconfirmed whether using cannabis has any anti-cancer effects.
However, it says there is some evidence that the chemicals in cannabis can help with symptoms such as nausea and pain.
“Some drugs that have been developed using the chemicals in cannabis have been effective in treating sickness caused by chemotherapy, or improving a person’s appetite,” Macmillan states on its website.
“But these studies have had mixed results when used in clinical trials. Because of the mixed results, the general feeling of experts is that there needs to be more research into the chemicals found in cannabis and their possible benefit.”
Newton-John's husband, John Easterling, grows the cannabis taken by the actor at the their Californian Ranch as part of his business, the Amazon Herb Company.
Newton-John says she takes the drug every morning, and at regular intervals throughout the day.
“My husband hands me all these herbs every morning and makes me a green algae drink,” she explained.
“He grows the plants and makes them into liquid for me. I take drops maybe four to five times a day.”
The Grease star revealed that alongside cannabis she has also cut sugar completely from her diet and meditates regularly.
“The first time I had breast cancer in 1992, I had a transcendental meditation teacher come and give me a mantra. And Deepak Chopra, who was a friend, gave me a mantra,” she revealed.
“These days, I pray. I meditate. I manage to find stillness just being in nature or playing with my dog or going down and playing with my little mini horses or chickens. I love animals. I find calmness in that.”
Despite speaking so candidly about her experiences with the disease, Newton-John admitted that she can be guilty of sugar-coating what she’s going through.
“I probably downplay things a lot,” she says.
“I hate talking about my health. I don’t like to worry people.”
“I am delighted to establish this partnership with Canopy Growth and share with them the knowledge I have gained after years of experience in the subject of living,” the 77-year-old said in a statement.
“I’m especially looking forward to our first collaboration together, which will offer sensible products for people’s beloved pets.”
In 2018, it was reported that the number of CBD consumers doubled following a rise in readily-available cannabis-derived products around the world.
CBD is a non-psychoactive chemical compound found in the marijuana plant and doesn't contain tetrahydrocannabinol (THC) – the main psychoactive perception and mood-altering component of cannabis.
This means that products containing CBD won’t lead to hallucinogenic effects like recreational use of marijuana is known to do.