Homeopathy doesn't always get a fair hearing in the media, according to Sheelagh Behan, an Irish homeopath and organiser of an international conference in Dublin this weekend. "The UK Sense About Science people have waged a campaign against homeopathy, as has the Skeptics Society here," she says. "There is much less criticism of homeopathy in France, Germany, Spain and Italy, where it is a more accepted part of the culture and every pharmacy offers homeopathy as an option."

Homeopathy is one of the best-known complementary therapies – partly because of scientists' criticisms of it, ironically – and it remains a healthcare choice for many. This weekend's event, which is drawing about 180 delegates from Europe, the United States and Australia, marks the 25th anniversaries of the Irish Society of Homeopaths and the European Central Council of Homeopaths.

Stephen Gordon, the council's general secretary, who will talk at the Irish Homeopathy Conference, says, "Homeopathy is used by over 100 million Europeans. In Germany over 60 per cent of the population use it. In other European nations it is a well-established therapy practised by both medical doctors and professional homeopaths."

The main criticism of homeopathy is that it uses such minute doses – its remedies are diluted many times – that its effects cannot be proven by any scientifically accepted standard. The doctor and science writer Ben Goldacre, a prominent critic, points out that, typically, "the treating substance is diluted by more than the total number of atoms in the universe". How can an almost infinitely dilute solution cure anything, he asks.

So how can people have confidence in homeopathic remedies? “There has been a lot of research worldwide into the electromagnetic activity within the higher-potency remedies,” Behan says. “Humans and animals have an electromagnetic charge that interacts on that level, although we don’t understand exactly yet how it works.”

It’s not an explanation that would convince scientists. So who visits Ireland’s 350 or so homeopaths? “Mothers who want their children to grow up as healthily as possible are the biggest group of people,” says Behan, who trained as a homeopath after her young son had a series of ear infections.

She adds that mothers know that bacteria are increasingly resistant to antibiotics and are unwilling to repeatedly take steroids or use inhalers for recurrent illnesses. “They find that the remedies, by strengthening the immune system, can greatly lessen the frequency of these infections and in some cases eliminate them all together.”