The funniest ad currently running on TV features a woman who claims to have discovered an all-natural remedy for arthritis -- namely, goat tears. The woman collects the precious material by singing "Danny Boy" to her goat herd and leading one goat to a grave site. "That's your mama," the woman says plaintively.
Like all good spoofs, the ad -- which actually promotes an arthritis cream called Thera-Gesic -- draws from reality. Over the centuries, people have been willing to rub all sorts of things into their sore joints. Today, arthritis sufferers can choose from a wide range of over-the-counter creams with different approaches to relief.
Bengay Ultra Strength contains 30% methyl salicylate, an aspirin-like compound, along with the cooling ingredients menthol and camphor. Users are directed to rub the cream on sore joints as needed, but no more than three or four times per day. A 2-ounce tube costs about $5.
Thera-Gesic contains 15% methyl salicylate and a little menthol. Users are instructed to spread a thin layer of the cream over sore spots no more than three or four times a day. According to the label, they can apply one or two extra layers at a time for more serious relief. A 3-ounce tube costs about $5.
Zostrix contains .075% capsaicin, a compound that gives chili peppers their heat. According to the directions, users should apply the product three to four times a day, every day. The website cautions that users might feel a burning sensation at first and that it might take a week or two to notice any results. A 2-ounce tube costs about $16.
The Bengay website says that the Ultra Strength cream -- "the strongest Bengay formula ever" -- offers "deep penetrating pain relief" for "minor arthritis, backache, and joint pain." The Thera-Gesic site claims that the cream "provides safe and effective pain relief without the worry." The Zostrix site says it has "proven clinical effectiveness in treating arthritis pain" and is the "#1 brand of topical analgesic recommended by doctors."
The bottom line
Rubbing any sort of cream or lotion into a sore joint can feel good, says Dr. Roy Altman, a rheumatologist at the Ronald Reagan UCLA Medical Center and a professor emeritus of rheumatology at UCLA. If the cream smells nice or feels cool, warm or tingly, all the better. "There's a sensation that it's doing something, and people believe in it," he says.
Still, there's no good evidence that any over-the-counter rub or cream offers real relief for arthritis, Altman says. Very few high-quality studies have ever investigated the products, he says, and the results that do exist have been far from convincing
As Altman noted in a March 2009 issue of the journal Postgraduate Medicine, the only placebo-controlled study of a salicylate cream applied directly to arthritic joints -- published 37 years ago -- found that the cream worked no better than the placebo.
Altman was the lead author of a 1994 study that found that a .025% capsaicin cream worked better than a placebo cream, but the relief was minor and didn't show up until four weeks of treatment.
Still, Altman says, capsaicin creams might be worth a try, especially for older people who may not be able to tolerate aspirin or other oral arthritis medications. Some patients notice relief, he says, though "the burning sensation is often intolerable." Because there's so little evidence behind salicylate creams, he doesn't recommend them, but he also doesn't tell patients who are already trying the products to stop.
Both salicylates and capsaicin supposedly relieve pain by irritating nerve endings in the skin. (Although salicylates are similar to aspirin, they don't have aspirin's power to ease inflammation.) In theory, the nerves become too distracted to notice arthritis pain. In reality, Altman says, the effect is usually either too fleeting or too mild to notice.
Menthol and camphor may add fragrance and zing to a cream, but there's no known pathway they could take to ease arthritis pain, Altman says.
Although the scientific evidence is admittedly sketchy, creams containing salicylates or capsaicin do seem to help some people, adds Dr. Scott Zashin, a clinical assistant professor of internal medicine in the rheumatology department of the University of Texas Southwestern Medical School in Dallas and a fellow of the American College of Rheumatology. It's not a cure, he says, but it can give you temporary relief.
And thinking back to his days as a high school soccer player, Zashin says he personally used enough Bengay to stink up the entire locker room. Why? "It made me feel better," he says.