Historically, people weren’t always careful in the sun.

Summer is fast disappearing in the Northern hemisphere and with it, the sunshine. Which is sad, as we all love a bit of sun, don’t we? Even if it doesn’t always love us, particularly those of us with fairer skin. Sunburn is no fun, but these days we also understand that it’s worse than a couple of days of painfully peeling skin: too much sun exposure can cause cancer.

Unfortunately there’s a whole generation – indeed more than one – who didn’t grow up with parents constantly slathering on the factor 50 (easy-to-use transparent sunscreens with very high SPFs didn’t appear on the market until the 1990s). For some sunburn was a regular part of summer, and those people need to be particularly vigilant for changes which might signify something nasty is going on.

On the plus side, these types of cancer are very treatable, and the outlook is hopeful. Often, the growth can be removed by surgery or even cryotherapy with very little scarring. Even the most dangerous kind of skin cancer, malignant melanoma, has a ten-year survival rate of around 90% with appropriate treatment.

But there’s the key: appropriate treatment. If you notice changes in your skin, especially a mole which is changing in colour or shape, you must see a qualified doctor as soon as you can.

What you should absolutely not do is visit the Black Salve page on Facebook (which I am not linking to for reasons which will be come obvious). This page, so Facebook tells me, is followed by nearly 17,000 users. It features a cheery cover photo of a family holding a canoe over their heads, and its profile picture is a pretty white and yellow flower.

Sanguinarine is a toxic salt extracted from the bloodroot plant. It’s infamous for its ability to destroy animal cells.

It’s all very suggestive of a homely, traditional remedy. The sort of thing your grandma had in her medicine cabinet. Very safe and “natural“. But while black salve might be a traditional remedy, it is anything but safe. Most preparations contain bloodroot, a source of the toxin sanguinarine, which kills animal cells.

Applying bloodroot to the skin destroys tissues and causes the formation of a large, black lump of dead flesh. Eventually this mass, called an eschar, falls off, leaving varying degrees of damage behind (internal use is also not recommended: consuming bloodroot can cause vomiting and loss of consciousness).

Bloodroot is easy to buy. Back in May this year the Good Thinking Society reported that eBay had removed “listings for dangerous cancer ‘cure’” following an investigation. Those listings were for black salve, and this was, of course, very positive news. Except for one thing: whilst listings for black salve were removed (and remain absent), listings for bloodroot were not. At the time of writing, a quick search reveals several bloodroot preparations still for sale.

At the time of writing, bloodroot is easy to find on eBay. The listing confirms that this is prepared from the “rhizome of certified organically grown Sanguinaria conadensis plants”.

Why is this such a bad thing? Because it’s easy to find recipes for making homemade black salve with bloodroot online, and using such mixtures can have truly horrific consequences. Last year the story of a woman who applied it to a basal cell carcinoma on her nose was widely reported. The black salve paste she used did so much damage that she ended up with a large hole in her nose through which she could actually draw air. Photos and video are available online (be warned: it’s gruesome).

Many patients turn to black salve as an alternative to what they imagine will be disfiguring surgery to treat their cancer. But, as in this woman’s case, the paste can do so much damage that far more extensive, reconstructive, surgery is ultimately needed.

Black Salve usually contains bloodroot and, sometimes, zinc chloride – another skin irritant.

It won’t surprise anyone to learn that dermatologists don’t recommend black salve. It can do enormous damage to the surface of the skin, resulting in scarring and a high risk of infection, and it does kill cancer cells along the way. But there is no guarantee that all of the cancerous cells deep within the skin will be destroyed. As a result, patients who’ve attempted to cure themselves may end up with cancerous tissue hidden, and growing, beneath a scar.

In fact, exactly this happened to an otherwise healthy 76 year-old woman in 2006. Her case is described in detail in the journal Dermatology Practical Conceptual – in summary, she refused surgery on a small melanoma on her leg. Instead, she bought black salve on the internet and applied it. A few years later the cancer had spread to her lungs, liver and lymph nodes.

Some people even recommend using black salve on breast cancers but this is, if possible, even worse. It’s highly unlikely that the salve will reach the entirety of a tumour which is beneath the skin. It is likely to do some horribly painful and disfiguring damage along the way, though.

Black salve is particularly popular in Australia, which of course has some of the highest rates of skin cancer in the world. But it’s available in the UK too. One online “herbal medicine” site is openly selling various formulations at prices ranging from £25-£100. Ironically, they describe their “Herbactive” product as “chemical free” (it isn’t, nothing is) and then go onto boast that it “now has a stronger concentration of bloodroot”. Fantastic.

They also sell a product which contains zinc chloride along with bloodroot. They claim zinc chloride is safe. It isn’t. It’s well-known to be a skin irritant, and should never be left in contact with skin.

The Black Salve Facebook page is full of anecdotes and testimonials, but light on evidence.

The Black Salve Facebook page is packed full of anecdotes and testimonials from people who claim to have used these mixtures safely. It’s all interspersed, of course, with the usual “Big Pharma” conspiracy theories. Namely, that the “truth” is being suppressed because there’s “no money in it for the pharmaceutical [industry].”

The irony is that reconstructive surgery is incredibly expensive, and the antibiotics, painkillers and other drugs that are inevitably needed to treat black salve victims aren’t free, either.

Given that Facebook’s community standards page states that: “We remove content, disable accounts and work with law enforcement when we believe that there is a genuine risk of physical harm or direct threats to public safety.” one has to wonder why the Black Salve page is still there. People are actually posting pictures of physical harm. What more does Facebook need?

Please, don’t be tempted to use black salve, or anything containing bloodroot. If you think you have a skin tumour see a properly qualified doctor and follow his or her advice.

It might literally save your life.

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