White Willow Overview

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.

In a 4-week, double-blind, placebo-controlled study of 210 individuals with back pain , two doses of willow bark extract were compared against placebo. ¹ The higher-dose group received extract supplying 240 mg of salicin daily; in this group, 39% were pain-free for at least 5 days of the last week of the study. In the lower-dose group (120 mg salicin daily), 21% became pain free. In contrast, only 6% of those given placebo became pain-free. Stomach distress did not occur in this study. The only significant side effect seen was an allergic reaction in one participant given willow.

Benefits were also seen in a double-blind, placebo-controlled trial of 78 individuals with osteoarthritis of the knee or hip. ² However, two subsequent double-blind, placebo-controlled studies performed by a single research group failed to find white willow more effective than placebo. ³ One enrolled 127 people with osteoarthritis (OA) of the hip or knee, the other 26 outpatients with active rheumatoid arthritis (RA). In the OA trial, participants received either willow bark extract (240 mg of salicin per day), the standard drug diclofenac (100 mg per day), or placebo. In the RA trial, participants received either willow bark extract at the same dose or placebo. While diclofenac proved significantly more effective than placebo in the OA trial, willow bark did not. It also failed to prove more effective than placebo in the RA study.

The most likely interpretation of these conflicting findings is that willow provides at best no more than a modest level of pain relief.

Standardized willow bark extracts should provide 120 to 240 mg of salicin daily.

1. Chrubasik S, Eisenberg E, Balan E, Weinberger T, Luzzati R, Conradt C. Treatment of low back pain exacerbations with willow bark extract: a randomized double-blind study. Am J Med. 109(1):9-14.
2. 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.
3. Biegert C, Wagner I, Lüdtke R, Kötter I, Lohmüller C, Günaydin I, Taxis K, Heide L. 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. 31(11):2121-30.