Acupuncture, a frequently used therapy, needs better needles to avoid potential problems, such as pain and skin reactions.
According to new research, despite improvements in the needle manufacturing process, surface irregularities and bent tips have not been completely eliminated.
A team of researchers in Australia looked at the surface conditions and other physical properties of the two most commonly used stainless steel acupuncture needle brands.
The researchers also compared forces and torques during the needling process.
The images revealed significant surface irregularities and inconsistencies at the needle tips, especially for needles from one of the brands which had been manufactured in China, said the research published online in Acupuncture in Medicine (AiM).
Metallic lumps and small, loosely attached pieces of material were observed on the surfaces of some needles.
Some of this residue disappeared after the acupuncture manipulation.
"If these needles had been used on patients, the metallic residue could have been deposited in human tissues, potentially causing reactions, such as dermatitis, although these reactions are reported extremely rarely," explained the authors.
Malformed needle tips could also have caused other problems, including bleeding, bruising, or strong pain during needling, which are quite common, they suggest.
Acupuncture, overall, is very safe, but it should be made even safer, say the researchers.
"Acupuncture needle manufacturers, including the well established ones, should review and improve their quality control procedures for fabrication of needles," they concluded.
According to Mike Cummings, medical director of the British Medical Acupuncture Association and associate editor of the journal, acupuncture is safe and if people experience pain during acupuncture, they should ask their practitioner to check on the quality of the needles they use.
An estimated 1.4 billion acupuncture needles are used each year worldwide, with China, Japan, and Korea the main suppliers. China provides up to 90 percent of the world's needles.
