The 10:23 Campaign is an awareness and protest campaign against homoeopathy organised by the Merseyside Skeptics Society, a non-profit organisation, to oppose the sale of homoeopathic products in the United Kingdom. The campaign has staged public "overdoses" of homoeopathic preparations.
In 2004, the Belgian skeptical organisation SKEPP made headlines when thirty skeptics at Ghent University performed a "mass suicide stunt" with an overdose of homeopathically diluted snake poison, belladonna and arsenic, in an attempt to publicly show that homeopathy does not work. When Belgian skeptics met with Merseyside Skeptics during a Skeptics in the Pub in 2010, the idea was adopted to hold an international event.
The campaign's name, 10:23, is an reference to Avogadro's number, which is approximately 6.022 x 1023.
The campaign aims to raise awareness of implausible and unsubstantiated claims made by homoeopaths. It opposes high street retailers, such as Boots UK, stocking homoeopathic remedies alongside mainstream medicines, saying that "the support lent by Boots to this quack therapy contributes directly to its acceptance as a valid medical treatment by the British public, acceptance it does not warrant and support it does not deserve."
The organisers state that homoeopathy is "an unscientific and absurd pseudoscience", and that, according to their statement, "There is nothing in it." They question the ethics of selling treatments to the public which have not been proven to be efficacious and are widely disregarded by the scientific community.
On 30 January 2010, members participated in a protest involving a mass overdose of homoeopathic products to demonstrate its inefficacy. Many protesters stood outside branches of Boots UK, other shops selling homoeopathic products, and other prominent public spaces and took 84 pills each of arsenicum album, 20 times the recommended dose.
A second overdose was organised for 5–6 February 2011. Worldwide, the campaign received commitments of participation from 70 cities in 30 countries. In the United Kingdom, events took place in Manchester, as part of the QED Conference, and Cardiff. The original Belgian SKEPP and the Dutch organisations Vereniging tegen de Kwakzalverij and Stichting Skepsis also participated in the worldwide 10:23 Campaign. They carried out their tongue-in-cheek suicide attempt in Brussels and Amsterdam specifically to protest the recognition of homeopathic preparations by the European Parliament.