I have written about it before, but here is Matt Parker:
I have just purchased a packet of Boots-brand 84 arnica homeopathic 30C Pills for £5.09, which Boots proudly claim is only 6.1p per pill. Their in-store advice tells me that arnica is good for treating "bruising and injuries", which gives the impression that this is a very cost-effective health-care option.
Unlike most medication, it didn't list the actual dose of the active ingredient that each pill contains, so I checked the British Homeopathic Association website. On their website it nonchalantly states that to make a homeopathic remedy, they start with the active ingredient and then proceed to dilute it to 1 per cent concentration. Then they dilute that new solution again, so there is now only 0.01 per cent of the original ingredients. For my 30C pills this diluting is repeated thirty times, which means that the arnica is one part in a million billion billion billion billion billion billion.
The arnica is diluted so much that there is only one molecule of it per 7 million billion billion billion billion pills.
It's hard to comprehend numbers that large. If you were to buy that many pills from Boots, it would cost more than the gross domestic product of the UK. It's more than the gross domestic product of the entire world. Since the dawn of civilisation. If every human being since the beginning of time had saved every last penny, denarius and sea-shell, we would still have not saved-up enough to purchase a single arnica molecule from Boots.
The amazing thing to me is that the folks lining up to be fleeced by this industry, and who will vociferously defend that they are not being fleeced, are the types of folks who are typically the first to throw up the barricades in the street when gas prices rise by 5 cents.
By the way, Arizona has a state board of homeopathic examiners to check ... what, exactly? To guarantee no active ingredient made its way into the product?
Here is a funny related video: