every two years. Many customer reviews have described themselves as repeat customers ordering multiple bracelets over time. Pseudoscientific theory Alternative health bracelets such as ionized jewelry are currently characterized as pseudoscience. Q-Ray's theory is grounded in traditional Chinese medicine (TCM) and pose similar benefits to acupuncture, another practice designed to balance the flow of qi and controversial in scientific communities in regard to its efficacy. Their website claims to optimize your natural positive energy and restore balance. No scientific research supporting these claims are referenced anywhere on their website or store. Instead, they advertise and rely heavily on testimonials as anecdotal evidence. No currently available research from third parties have verified their claims. Radioactivity A number of wearable products marketed as "negative ion generators" have actually been found to contain radioactive thorium or uranium, apparently to generate negative ions as a result of radioactive decay. While the activity is typically low, adverse affects from cumulative exposure to the radioactivity in these products cannot be ruled out. Research A placebo controlled randomized trial study published in the journal Mayo Clinic Proceedings compared the effect of ionized bracelet produced by Q-ray to an identically appearing placebo bracelet. The study found no difference between the ionized bracelet and control with respect to musculoskeletal pain, suggesting the effects of Q-ray bracelet was due to the placebo effect. See also List of topics characterized as pseudoscience Quackery Negative air ionization therapy Power Balance Hologram bracelet Magnet therapy Energy medicine References Energy therapies Pseudoscience Consumer fraud