Food regulators in the UK have reduced the recommended safe daily dose of cannabidiol (CBD) due to possible health risks, The Guardian reported.

In a reversal of previous official guidance, the Food Standards Agency (FSA) and its Scottish counterpart had updated their advice on the cannabis extract, the 12 October report said.

The updated guidance recommended healthy adults to limit their intake of CBD from food to 10mg/day, which equated to four or five drops of 5% CBD oil.

Previous advice, dating from 2020, had set the limit much higher at 70mg/day, the report said.

“The more CBD you consume over your lifetime, the more likely you are to develop long-term adverse effects, like liver damage or thyroid issues,” the FSA’s chief scientific advisor Prof Robin May was quoted as saying.

May advised consumers to check the labels of the products they used and to consider following the new advice.

“The level of risk is related to how much you take, in the same way it is with some other potentially harmful products such as alcoholic drinks,” he added.

The FSA said the updated guidance was based on new evidence from the industry as well as input from its independent scientific committee.

Although there were currently some products on sale containing more than 10mg/serving of CBD, the recommendation was advisory and regulators were not requesting products to be withdrawn, The Guardian wrote.

One of the non-psychoactive chemicals found in the hemp plant – not the illegal mind-altering THC (tetrahydrocannabinol) – CBD sales surged with the ingredient added to a wide range of products from fizzy drinks to face cream, the report said.

More recently the industry has been in limbo after the FSA began to intervene, according to the report.

Classed as a ‘novel’ food, CBD products must be approved before going on sale and the FSA had created a list of products for consumers to consult, although it had not authorised any of them, The Guardian wrote.

According to Marika Graham-Woods, executive director of the Cannabis Trades Association, the FSA’s decision was unfair with the new guidance only advisory.

“All this does is frighten consumers and retailers and it stops the industry going forward again. I don’t see any benefit in what they have done,” she was quoted as saying.

Based on the data assessed, the FSA said there was “no acute safety risk” with consuming more than 10mg of CBD/day.

However, above that level, and over a period of time, there was “evidence of some adverse impacts on the liver and thyroid”.

The FSA also underlined that CBD should not be taken by people in vulnerable groups, including children, those on medication or women who were pregnant, breastfeeding or trying to conceive.

FSA chief executive Emily Miles was quoted as saying the association had always advised the public to “think carefully” about taking edible CBD products and it would continue to review its advice based on the evidence.

“We understand that this change to our advice will have implications for products currently on the market that contain more than 10mg/serving of CBD,” she said. “We will be working closely with industry to minimise the risk that consumers are not exposed to potentially harmful levels of CBD.”