Honestly, I don’t think I could make up something this daft if I tried. Thanks to an astute member of the NZ Skeptics Facebook group, I now know about a New Zealand company - Hippo Health - who are marketing a fascinating sun block for animals.

Their schtick is that the sweat of a hippo from behind its ear contains norhipposudoric acid (opens new window), and that this acts as a sunblock - after all, as the company says, "Have you ever seen a sunburnt hippo?". The company claims that this orange substance, when excreted, somehow quickly coats the entire skin of the hippo, and protects it from UV rays. From there, the company says that their homeopathically diluted version of this product also provides sun protection when swallowed - and they hint that it should work on people as well as animals:

"Does SOL Plus work on People?

On a daily basis our team at Hippo is asked whether it works for people too. Logically we would like to say ‘of course’ but because we don’t have clinical trials for people, our official stance is that we don’t sell or market it as a people sunscreen. We suspect there are a lot of people unofficially helping themselves to their horse’s bottles of Sol Plus and we welcome any feedback."

There’s a lot wrong with this product, and the claims that are being made about it. Firstly, although tests have shown the chemical, and it’s red counterpart hipposudoric acid, do have some UV protective properties when applied to the skin, there’s no explanation of how this would work when taken internally. But bigger than this are the problems that come with this being a homeopathic product.

Homeopathy is a fully discredited pseudo-scientific idea about how diluted substances might help our bodies to heal - in reality, homeopathy just doesn’t work. So, it’s likely that this hippo sweat, when diluted in water to a point where no molecules of the acid are present, won’t retain any of the properties of the active chemical.

On top of the dilution idea, homeopathy operates under a "like cures like" model, where something which in concentrated form causes a set of medical symptoms will cure similar symptoms when it is diluted. So, for example, diluted caffeine (a stimulant) is said to treat ADHD and diluted onion (which makes you cry and your nose run) will apparently treat colds and flu.

So, if we apply this to our homeopathic hippo sweat (I can’t believe I’ve actually written those words down), this should mean that our concoction might be expected to help you tan. But no, in this case the principle of like cures like is thrown out the window, and instead diluted hippo sweat, when swallowed, is being sold in New Zealand as an effective sunscreen.