Information about the Supplement I-flex and Arthritis

Q: Does i-flex really help relieve arthritis pain?

A: Maybe. Several small studies suggest that i-flex, a standardized extract made from rose hips and seeds, may provide some relief from chronic pain, at least in the short term. The evidence, though not consistent, seems strongest for osteoarthritis, but the supplement may also benefit people who have rheumatoid arthritis and low back pain.

I-flex is made primarily from the hips (fruit) of a wild rose called Rosa canina (R. canina, dog rose). The product originated in Denmark and is marketed under different brand names, typically as capsules.

The Natural Standard, which evaluates research on herbal and other alternative treatments, gave i-flex a B (good) rating for pain relief from osteoarthritis. A 2008 analysis, which looked at three studies funded by the manufacturer, concluded that the extract "seems to have a consistent, small to moderate efficacy" in people with arthritis.

The product is thought to inhibit COX-1 and COX-2 enzymes, which play important roles in inflammation and pain, according to a 2007 review in Phytotherapy Research. More research is needed to test its effectiveness, the authors noted.

If you have arthritis and want to try i-flex, keep in mind that its long-term safety and its interactions with drugs are not known. One concern: because the extract may work similarly to pain relievers such as aspirin by inhibiting COX-1 and COX-2 enzymes, it may have some of the adverse effects of those drugs, notably stomach bleeding. It's also not known whether other rose hip supplements would have the same effects as i-flex, though they are not typically marketed for arthritis.

Source: Originally published in The University of California, Berkeley Wellness Letter (June 2011)

Publication Review By: the Editorial Staff at

Published: 05 May 2011

Last Modified: 09 Oct 2014