Trendy charcoal toothpaste touted as healthy may actually cause tooth decay and even cancer, a new study found.
Charcoal-based toothpastes and powders are promoted with claims they can remove stains, whiten teeth , are non-abrasive, anti-bacterial and even had the ability to strengthen teeth.
Manufacturers also maintained their products are "clinically proven," approved by dentists, and most are advertised to appeal to "woke" consumer with claims they are 100 per cent natural, vegan, eco-friendly, and cruelty free.
But the review commissioned by the British Dental Bleaching Society, described the marketing over-reliant on gimmicks and 'folklore' to substantiate their claims.
It warned the products could cause tooth abrasions and the charcoal can in fact inactivate the fluoride contained in a minority of toothpastes, which fights tooth decay.
It question the claims to whiten teeth and remove plaque, bacteria and stained material.
The review looked at the product information of the 50 charcoal toothpastes and found only eight per cent contained fluoride.
More than half claimed to have therapeutic benefits and 96 per cent claimed to have tooth whitening capabilities.
Three in ten (30%) claimed the toothpaste aided remineralisation, strengthening or fortification of the teeth, just over a quarter (28%) that it was low abrasiveness, nearly half it had a capacity for detoxification (46%) or antibacterial or antiseptic properties (44%), and an eighth (12%) it possessed antifungal benefits.
Nearly nine in ten (88%) used adverts that claimed they were eco-friendly, ecological, herbal, natural, organic and pure and over half (54%) used at least two such terms.
Yet none of these claims have been proven and only a tenth included some form of dental professional endorsement.
Regarding whitening capabilities, experts regarded the high absorbency of charcoal to contain insufficient availability of any free radical bleaching agent capable of chemically reducing intrinsic staining present in enamel and bony tissue.
It also found there could be health risks due to the possible inclusion of human carcinogenic polyaromatic hydrocarbons in charcoal - a group of chemicals that occur naturally in coal, crude oil, and gasoline.
Others claims the addition of bentonite clay in some pastes hold in plaque, bacteria and stained material in the pores of the charcoal which when brushed away, leaves the tooth surfaces free of any deposits.
But the researchers said there was "insufficient supporting scientific data" backing this claim up.
Lead author Dr Linda Greenwall said: "It's imperative that consumers check the ingredients on the packaging of charcoal-based products before usage to ensure they include fluoride, calcium and phosphate to strengthen and protect tooth enamel.
"Tooth pastes need to contain therapeutic ingredients to strengthen and protect teeth and reduce gingivitis.
"Not all charcoal toothpastes are the same and some could potentially be causing lasting damage to a person's teeth.
"Toothpastes should contain fluoride to have additional health benefits for the teeth.
"The most worrying aspect about the marketing of charcoal pastes and powders, appears to be a strong emphasis on the benefits which appeal to consumers, which have yet to be disproved.
"This scientifically claimed until proved wrong approach is favoured over substantiated, evidence-based promotion."
Co-author Dr Joseph Greenwall-Cohen said: "Many people are seduced into thinking that these charcoal-based products are 'healthy' due to clever marketing tactics and claims.
"However, these are completely unfounded as there is no evidence whatsoever that proves this.
"Just because these toothpastes are fashionable, does not mean they are healthy for you."
The review which looked at 15 previous reviews and studies was published in the British Dental Journal.