Doctors, medical experts and charities have raised concerns about events by a controversial “self-healing” coach taking place in Ireland and the UK, saying her commentary poses “tangible and sometimes life-threatening risks to patients”.
Barbara O’Neill is a self-described naturopath and nutritionist who has written books on health and nutrition, shares videos on social media and lectures internationally about self-healing and natural remedies.
She previously told vulnerable patients their cancer was a fungus that could be cured with bicarbonate of soda rather than through conventional medical treatment, and discouraged vaccination and antibiotics.
In 2019, Australia’s New South Wales Health Care Complaints Commission banned her for life from providing any health services either voluntarily or in a paid capacity, including giving lectures in her native country.
The commission’s investigation found O’Neill never held any membership with any accredited professional health organisation and had failed to obtain any relevant health-related degrees or diplomas.
According to the investigation she also failed to keep records of consultations with clients, falsely claimed to be able to cure cancer, did not treat clients in a safe or ethical manner and posed a risk to the health and safety of members of the public.
She has a large audience on social media, with 3.6 million Instagram followers and 356,000 subscribers on YouTube.
O’Neill is due to speak at City North Hotel and Conference Centre in Gormanstown, Co Meath, next week. Tickets for her event, which is taking place over three days, range from €70 for one day, to €195 for a three-day ticket. “Premium” tickets cost up to €115 per day, or €320 for the three-day bundle.
According to the agenda, the event will discuss depression, cancer, natural treatments, and DNA and the “true cause of disease”.
“Our mission is rooted in the restorative power of God’s love and the healing teachings of Scripture,” the event page states.
“We are committed to nurturing the body, mind and soul, guiding individuals on a path to comprehensive well-being in alignment with God’s intended design for health and wholeness.”
In a letter to the Irish and UK venues that are hosting her tour, doctors, heads of charities and medical professionals raised concerns about the risk these events could pose to vulnerable individuals.
“As part of an international speaking tour, O’Neill is due to speak to your venue in October 2026, something she is explicitly banned from doing in her home state. At the event, she will spread dangerous health fictions to a susceptible audience, leeching off an illusion of legitimacy afforded to her by the surrounds of your respectable establishment,” the letter said.
“There is ample evidence that such misinformation can and will harm patients, and O’Neill has demonstrated a remarkable callousness about these harms. We appreciate that this is something with which you would likely want no association.”
It added: “We strongly feel, however, that this information should help in reaching an informed course of action, and are happy to provide supporting evidence and further information if required. While ultimately the choice whether to host such an event or not is down to yourselves, we hope that this missive is helpful in elucidating why medical science and healthcare professionals have justified concerns, and the tangible and sometimes life-threatening risks to patients that exposure to such toxic fictions pose.”
The letter was co-ordinated by David Robert Grimes, a science communicator and adjunct associate professor in biostatistics at Trinity College Dublin, who has authored a book on misinformation.
Among the signatories are Orla Dolan, chief executive of Breakthrough Cancer Research; Colin Doherty, head of the school of medicine at Trinity College Dublin; Derek Power, consultant medical oncologist in Cork; Jennifer Feighan, chief executive of the Irish Nutrition and Dietetics Institute; and Susan Smith, professor of general practice in Trinity College, among others.
The conference centre was contacted for comment. O’Neill was also contacted for comment.