The white willow was introduced into the United States form Europe and can be found next to rivers and streams throughout the country. The bark is the part of the willow used, and is easily removed in the spring when the sap begins to flow.
White Willow Bark contains salicin, which the body converts to salicylic acid and has the same effect on the body as aspirin without any of the side effects. In fact, White Willow Bark was the basis for the synthesis of aspirin. History of usage of White Willow Bark goes back as far as 500 BC when ancient Chinese healers began using it to control pain.
Today, white willow bark is often used as a natural alternative to aspirin - one of the most common uses in dietary supplements is as an adjunct for weight loss.
As a weight loss aid, white willow bark extract offers little to no benefits by itself. In combination with other dietary supplements, however, white willow is thought to extend or increase the activity of several thermogenic ingredients in elevating energy expenditure and promoting fat metabolism.
There are no known dietary sources of white willow. Use must come through supplementation of oral capsules or topical creams. It is possible to consume white willow by chewing on the bark of the Salix Alba tree, thereby leaching the glycosides from the bark and ingesting them sublingually.
Although white willow is the species of willow tree most commonly used for medicinal purposes, other salicin-rich species are employed as well, including crack willow (Salix fragilis), purple willow (Salix purpurea), and violet willow (Salix daphnoides). These all may be sold under the label of willow bark.
White willow bark should not be taken with aspirin or NSAIDs (nonsteroidal anti-inflammatory drugs) such as ibuprofen and naproxen; in combination, the herb and these drugs increase the chance of side effects such as stomach bleeding.