Google has been accused of promoting an unproven cancer cure which can burn through people’s skin.
Adverts for black salve, an ‘extremely dangerous’ paste which is applied to the skin, appeared in the sponsored section of the search engine.
Touted as a treatment for warts, skin tags and even skin cancers, the controversial remedy works by burning through the flesh.
It can leave customers mutilated, with permanent scars and patients may potentially avoid effective medicines in favour of the paste.
Health authorities in the US and Australia have warned people not to use the risky treatment, and the US banned its sale as a cancer cure, but it is still available online.
One advert promoted by Google showed black salve on sale for £13, and the company selling it claimed it could cure haemorrhoids and cancer.
It claimed the product was a ‘natural antiseptic’, The Times reported.
Another, selling the black salve for £30, claimed the paste has ‘been long known’ to remove skin problems such as skin tags, warts, boils and moles.
The active ingredient in black salve is a plant called bloodroot, which has a corrosive effect on human tissue, meaning it burns it away.
While patients may want warts and boils burned off, the product will also eat through healthy skin and cause permanent damage.
‘Black salve is extremely dangerous,’ Cancer Research UK’s Martin Ledwick told The Times.
‘There’s no evidence that it helps to treat cancer and we urge people not to use this unsafe substance.’
But companies selling black salve or people promoting its use may not always be truthful about its damaging effects.
Although black salve hasn’t been specifically banned in the UK, advertising anything as a cancer cure is against the law.
The Cancer Act 1939 banned any advertising of cancer drugs to the general public, whether from pharmaceutical companies, doctors or other firms.
Black salve is derived from the North American plant Sanguinaria canadensis – also known as ‘blood root’ or ‘Indian paint’. The homeopathic remedy’s ingredients vary but often include zinc chloride, which is corrosive to metals.
The plant was used by native Americans to treat infected wounds, however, it can corrode skin, leaving a thick dark scar known as an eschar.
Supporters claim it separates healthy and damaged tissue, however, there is no evidence supporting this.
Studies suggest that all tissue that comes into contact with black salve gets damaged, leading to inflammation, and finally a dark scab and dead tissue that falls away.
There is even evidence it can cause cancers to spread, as well as leading to extreme pain.
Although it can be bought online, the US Food and Drug Administration prohibited its sale at the end of the 1950s due to a lack of evidence and safety concerns.
In April last year, the FDA sent warning letters to 14 companies urging them to change or remove fraudulent claims about black salve being a cancer cure on their websites or face legal action. It was prohibited in Australia in 2012.
Beforehand, self-proclaimed cancer specialist Harry Hoxley sold black salve to treat both internal and external cancers in clinics across the US.
It can appear under a variety of brand names including Cansema (Alpha Omega Labs), Black Ointment (Dr Christopher’s Original Formulas) and Herb Veil 8 (Altered States). None state the exact ingredients.