Protesters today staged a mass "overdose" of homeopathic remedies in a bid to prove that the medicines are worthless.
The demonstration, organised by the Merseyside Skeptics Society (MSS), saw supporters gather outside branches of Boots to swallow entire bottles of tablets.
Campaigners have called on the high street chain to withdraw all homeopathic treatments from its shelves, which they say are "scientifically absurd".
Homeopathy is a system that uses very highly diluted substances to trigger the body to heal itself.
Michael Marshall, from the MSS, said: "We believe that they shouldn't be selling sugar pills to people who are sick. Homeopathy never works any better than a placebo. The remedies are diluted so much that there is nothing in them."
He took a remedy said to contain arsenic but explained that the chances of finding one molecule of the substance in the tablets were incredibly small.
Protesters gathered outside Boots branches in Liverpool, Manchester, Glasgow, Edinburgh, London, Leicester and Birmingham.
Mr Marshall said that consumers trust the company and it should not sell the remedies alongside mainstream medicines.
Similar demonstrations were planned in Canada, Spain, the US and Australia, he added.
The Society of Homeopaths said treatments are "person specific" and based on taking a series of small doses, so it did not expect any reaction in the protesters unless one already had symptoms matched to their remedy.
Chief executive Paula Ross said: "This is an ill advised publicity stunt in very poor taste, which does nothing to advance the scientific debate about how homeopathy actually works."
Paul Bennett, Professional Standards Director from Boots, said the company follows advice from the Royal Pharmaceutical Society of Great Britain on the correct selling of complementary medicines.
He went on: "Homeopathy is recognised by the NHS and many health professionals and our customers choose to use homeopathy.
"Boots UK is committed to providing our customers with a wide range of healthcare products to suit their individual needs, we know that many people believe in the benefits of complementary medicines and we aim to offer the products we know our customers want.
"We would support the call for scientific research and evidence gathering on the efficacy of homeopathic medicines. This would help our patients and customers make informed choices about using homeopathic medicines."