Muscle rubs may not offer any relief from aches and pains
There is no convincing evidence that liniments and balms work on sore muscles and joints, say experts.
There are unlimited over-the-counter purchases and more than a million prescriptions a year for rubefacient rubs, giving a blood rush to the skin.
Cochrane researchers who looked at data from 16 studies looking at creams containing painkiller salicylate found no proven benefits.
They said other analgesic gels may well work, and recommended more research.
Strains and sprains
They looked at 16 studies involving nearly 1,300 patients using creams containing salicylate - a close drug relative of aspirin.
Results from four of the studies showed topical salicylates performed better than dummy creams against acute pain, but when lower quality studies were excluded, the results were not statistically significant.
Again, when used for chronic conditions, salicylates performed better than placebos.
But only one in six patients with chronic pain from conditions like osteoarthritis benefited substantially from using the muscle rubs compared with one in three using non-steroidal anti-inflammatory painkiller gels like ibuprofen or diclofenac.
Recently published guidance on osteoarthritis from the National Institute for Health and Clinical Excellence concluded that rubefacients should not be recommended for the treatment of this joint disease.
Lack of evidence
Lead researcher Dr Andrew Moore, of the Nuffield Department of Anaesthetics at the University of Oxford, said:"When it comes to rubefacients they do not work well enough to take any notice of them.
Rubefacients irritate the skin, causing redness
The review focused on creams containing salicylates
"What we know does work is topical non-steroidal anti-inflammatory gels like ibuprofen. There is pretty good evidence that they work well and are pretty safe.
"Larger and higher quality controlled trials of topical rubefacients are needed to establish whether these treatments really work.
"We also need more studies on other rubefacients as we were only able to assess the effectiveness of the salicylate formulations in this review.
"But it is important to remember that not all analgesic gels or creams are the same, and for others there is very good evidence of effectiveness."
Peter Gladwell, a clinical specialist physiotherapist working in pain management, said some patients might want to try rubefacients alongside other treatments, including exercise and relaxation techniques.
"A patient with chronic pain, considering the possible use of a rubefacient, will learn from this review that they have a one in six chance of achieving 50% pain relief.
"They have a one in three chance of achieving 50% pain relief using a non-steroidal anti-inflammatory gel."
He suggests, after weighing the risks and benefits and having talked with a health professional, a patient may want to try the anti-inflammatory gel first, and move on to try a rubefacient if the anti-inflammatory gel is unhelpful.