White WillowSalix alba
Willow bark has been used as a treatment for pain and fever in China since 500 BC. In Europe, it was primarily used for altogether different purposes, such as stopping vomiting, removing warts, and suppressing sexual desire. However, in 1828, European chemists made a discovery that would bring together some of these different uses. They extracted the substance salicin from white willow, which was soon purified to salicylic acid. Salicylic acid is an effective treatment for pain and fever, but it is also sufficiently irritating to do a good job of burning off warts.
Chemists later modified salicylic acid (this time from the herb meadowsweet) to create acetylsalicylic acid, or aspirin.
What Is White Willow Used for Today?
As interest in natural medicine has grown, many people have begun to turn back to white willow as an alternative to aspirin. One double-blind, placebo-controlled
Aspirin and related anti-inflammatory drugs are notorious for irritating or damaging the stomach. However, when taken in typical doses, willow does not appear to produce this side effect to the same extent.
This latter finding raises an interesting question: If willow provides only a small amount of salicylic acid, how can it work? The most likely answer seems to be that other constituents besides salicin play a role. Another possibility may be that the studies finding benefit were flawed, and that it actually does not work.
What Is the Scientific Evidence for Willow?
In a 4-week, double-blind, placebo-controlled study
However, two subsequent double-blind, placebo-controlled studies performed by a single research group failed to find white willow more effective than placebo.
The most likely interpretation of these conflicting findings is that willow provides at best no more than a modest level of pain relief.
Evidence suggests that willow, taken at standard doses, is the equivalent of 50 mg of aspirin, a very small dose.
Willow doesn't impair blood coagulation to the same extent as aspirin,
For this reason, white willow should not be given to children, due to the risk of Reye's syndrome. It should also not be used by people with aspirin allergies, bleeding disorders, or kidney disease. In addition, it may interact adversely with "blood thinners," other anti-inflammatory drugs, methotrexate, metoclopramide, phenytoin, probenecid, spironolactone, and valproate.
Safety in pregnant or nursing women, or those with severe liver or kidney disease, has not been established.
Interactions You Should Know About
Avoid combining white willow with the following medications:
- Blood-thinning medications, such as:
6. Schmid B, Ludtke R, Selbmann HK, et al. Efficacy and tolerability of a standardized willow bark extract in patients with osteoarthritis: randomized, placebo-controlled, double blind clinical trial [translated from German]. Z Rheumatol . 2000;59:314-320.
10. Biegert C, Wagner I, Ludtke R, et al. Efficacy and safety of willow bark extract in the treatment of osteoarthritis and rheumatoid arthritis: results of 2 randomized double-blind controlled trials. J Rheumatol . 2004;31:2121-2130.
Last reviewed April 2009 by EBSCO CAM Review Board
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