The first ever study of the adverse effects of acupuncture in state-funded acupuncture clinics in the UK has found that the procedure is largely safe, but not as safe as advertised. In extreme cases, it could even put lives at risk.

Despite this, claims that acupuncture is completely safe could soon lead to the procedure being funded by Medicare, the US government-funded medical benefits programme. Acupuncture is already government-funded in much of Europe.

Investigators from the National Patient Safety Agency, part of the UK's government-funded National Health Service, assembled all reports of adverse events following acupuncture treatment in NHS clinics between 2009 and 2011. In these clinics, acupuncture is provided by conventionally qualified doctors and therapists, who are also trained to perform acupuncture. This is offered in several NHS hospitals, GP's surgeries and nearly all NHS pain clinics.

The investigators found 325 reports of adverse effects. There is no data for the total number of acupuncture treatments given, so the frequency of these events cannot be calculated. But other studies in Germany and the UK have found adverse effects following some 10 per cent of treatments.

Some of the reports were merely of sloppy practice. In 100 cases, patients were left with needles still in them, sometimes hours longer than intended or even after they or the staff went home. Some needles subsequently had to be surgically removed.