The FDA has issued a warning over cannabis-based therapies which promise the ability to cure cancer, asserting that such treatments which provide no proven therapeutic benefits or safety profile is a violation of the Federal Food, Drug and Cosmetic Act, presenting a real potential danger to patient lives.

The FDA has so far no approved any medicinal products for any disease that contain cannabidiol, a compound extracted from cannabis which is believed to have many medical benefits. As no medications of this kind have been regulated, it’s impossible to adequately assess their safety or efficacy, meaning they could pose a significant threat to unwitting buyers.

The regulator also said that it has issued warnings to four companies selling such products, ordering them to address their violations and explain how they plan to correct them. These companies include Greenroads Health, Natural Alchemist, That’s Natural! Marketing and Consulting and Stanley Brothers Social Enterprises.

Together, the companies are selling more than 25 cannabis-based products online, making a number of baseless claims such as "makes cancer cells commit ‘suicide’ without killing other cells", "combats tumour and cancer cells" and "effective in treating tumours from cancer – including breast cancer".

"Substances that contain components of marijuana will be treated like any other products that make unproven claims to shrink cancer tumours," stated FDA Commissioner Scott Gottlieb. "We don’t let companies market products that deliberately prey on sick people with baseless claims that their substance can shrink or cure cancer and we’re not going to look the other way on enforcing these principles when it comes to marijuana-containing products."

He added: "We recognise that there’s interest in developing therapies from marijuana and its components, but the safest way for this to occur is through the drug approval process – not through unsubstantiated claims made on a website. We support sound, scientifically-based research using components derived from marijuana, and we’ll continue to work with product developers who are interested in bringing safe, effective, and quality products to market."