Tomorrow, I plan to travel to the centre of London where I will take a huge overdose – in public – consuming an entire bottle of pills.

I will not be alone. I'll be joined by several hundred others in London and around the world who will also be overdosing. No harm will come to us because the pills will be homeopathic, and therefore contain no active ingredient – just sugar.

This is the 10:23 campaign and our aim is to demonstrate to the public in the strongest way possible that these pills, sold to poorly customers by companies like Boots have, literally, nothing in them.

Boots for one sells homeopathic remedies even though it admits that there is no reason to believe they are clinically effective. Some may argue that homeopathy is harmless, but that simply isn't the case. The pills themselves may be ineffective, but their impact on public health can be toxic.

When the UK government ploughs more than £4m of taxpayers' money into homeopathy annually, and leading pharmacists stock their magic potions, it serves to legitimise the industry, to suggest that somehow homeopaths are on a par with real doctors.

The consequences of that can be disastrous, whether it's the suicide of a patient who should be taking antidepressants, delayed treatment for a serious illness, or a traveller packing "anti-malarial" pills that don't actually work.

The online "What's the harm?" project lists numerous people who have been harmed by homeopaths who were deluded enough to believe they were offering genuine medical advice.

There has been a steady trickle of deaths, such as "Ms A" who died after a homeopath informed her she did not need to take her heart medicine, or the six-month-old baby who died after his parents, one of whom was a practising homeopath, refused to allow him to be given conventional medicine.

Senior homeopaths claim that this sort of thing is rare, but investigations tend to show otherwise. Deluded homeopathic adventurers are setting up clinics and running research projects in places like Tanzania, claiming to be able to treat Aids and denouncing antiretroviral drugs as evil, behaviour that is estimated to have already been responsible for over a third of a million deaths in South Africa.

Shockingly, these sorts of activities are sanctioned and funded by at least one British homeopathic organisation, as revealed in the 2007 accounts of the registered charity the Homeopathic Action Trust and exposed by the blogger Gimpy.

Of course, senior homeopaths in Britain are happy to provide what they believe is scientific evidence for homeopathy, but when scrutinised, the evidence quickly falls apart.

The British Homeopathic Association lists numerous studies in a document on its website, claiming to offer evidence in favour of homeopathy, and yet many of the studies cited simply don't.

To pick a random example, the fifth citation, a Cochrane review, concludes that "Current evidence does not support a preventative effect of Oscillococcinum-like homeopathic medicines in influenza and influenza-like syndromes." And yet the BHA cites this as evidence supporting the effectiveness of homeopathy in flu.

Even where trials are cited that do produce a positive result, the result is qualified. The third reference, for example, is a trial reported in the BMJ that notes that the results are not sufficient to draw clinical conclusions from, and that more research would be needed. The remainder of the document, and the BHA's written evidence to parliament, is riddled with similar anomalies.

Indeed, the BHA seems to accept that the evidence is lacking. Its written submission to a Commons cross-party science committee investigation into homeopathy last year makes the point that, due to poor methodology, the papers included in its review can't be used to demonstrate clinical significance.

In a press release last year, the BHA described the number of good trials in homeopathy as "minuscule".

So not only have homeopaths been unable to produce good evidence that homeopathy works, but they've actually admitted to parliament that the quality of evidence they have is seriously lacking. This after 200 years of research.

No wonder then that Boots found itself in hot water last year after admitting to the science committee that it sells homeopathic remedies without having any evidence that they work.

Personally, I can't see how handing out treatments for which you admit you have no evidence can be compatible with being a registered pharmacist. And as campaign members buy their pills ahead of the mass overdose tomorrow, some of the stories we're hearing are downright disturbing. One man spoke to a pharmacist explaining that he was buying pills to take part in a homeopathic overdose. The pharmacist admitted to having no idea what homeopathy was, let alone whether or not it worked, but happily sold him six bottles.

Homeopathy does not work beyond placebo, it is a menace to public health and a drain on the limited resource of the NHS. It is an 18th century quack medicine consisting of magical rituals practised by deluded, cargo-cult "doctors" that has no place in government thinking, and it should not be endorsed by the registered pharmacists who are at the frontline of public health in the UK.

As the Commons science committee prepares to submit its report on homeopathy to the government, now is the time for everyone who believes in evidence-based medicine to stand up and make this crystal clear. Please join us at your nearest 10:23 event.

Martin Robbins writes for The Lay Scientist