There is not enough evidence to support using gels and creams containing rubefacients for chronic and acute pain, according to a systematic review by Cochrane Researchers. Rubefacients cause irritation and reddening of the skin, due to increased blood flow. The review focused on formulations containing salicylates, which are widely prescribed or sold over the counter as topical treatments for sports injuries and muscle pain.
"At present, due to a lack of high quality evidence, we can't say exactly how effective rubefacients are for acute injuries and there are certainly other more effective treatments which could be prescribed for use in chronic conditions like osteoarthritis," says lead researcher Andrew Moore, of the Nuffield Department of Anaesthetics at the University of Oxford in the UK.
There are over a million prescriptions each year for rubefacient gels and creams such as Movelat. As with Movelat, the rubefacient compounds in many of these products are salicylates, which, while they are related to aspirin, may not work in the same way, especially when applied to the skin. They are referred to as "counter-irritants" because it is thought that they offset localised pain through local skin irritation.