Pregnant women, breastfeeding mothers and people taking medication should not eat foods containing CBD, an ingredient derived from the cannabis plant, a regulator has warned.

In its first ever safety advice to consumers on cannabidiol products, the Food Standards Agency (FSA) also cautioned others who might eat such foods not to have more than 70mg a day.

And in a warning to CBD businesses, the regulator said goods could be taken off the shelves if those in the industry failed to give more information about the safety and contents of their products by the end of March next year.

Producers are being asked to apply to the FSA for “novel food authorisation” which, the agency said, would reassure the public about the safety of CBD products.

Extracts of CBD, a chemical found naturally within the cannabis plant, are contained in a range of products including oils, confectionery and drinks.

The FSA chief executive, Emily Miles, said while such products were “widely available on the high street” they were not properly authorised.

“The CBD industry must provide more information about the safety and contents of these products to the regulator before 31 March 2021, or the products will be taken off the shelves,” she said on Thursday.

“Also today, we are advising that CBD could be risky for vulnerable groups, and suggesting an upper limit of 70mg a day for everyone else taking the product.

“The actions that we’re taking today are a pragmatic and proportionate step in balancing the protection of public health with consumer choice. It’s now up to industry to supply this information so that the public can be reassured that CBD is safe and what it says it is.”

While the FSA has issued guidance, which applies only to England, Wales and Northern Ireland, it is local authorities that have the power to enforce the novel foods legislation.

Prof Alan Boobis, chairman of the Committee on Toxicity, which advises the FSA and Department of Health, said while the risk from CBD was not certain, the agency’s approach was a “sensible and pragmatic” one.

He said: “My committee has reviewed the evidence on CBD food products and found evidence there are potential adverse health effects from the consumption of these products.

“We are particularly concerned about pregnant or breastfeeding women and people on medication.

“We don’t know enough to be sure about such a risk but I am pleased with the sensible and pragmatic approach the FSA is taking. The committee will continue to keep these products under review in the months ahead.”

Thursday’s announcement does not affect people who take medically prescribed CBD or cannabis, the FSA said.