Dating back to about 400 B.C., white willow bark is a pain reliever and fever reducer, very similar to aspirin. White willow bark comes from a tree native to Asia and Europe. In the 1800's, European scientists discovered the active ingredient in white willow bark, salicin. Soon, scientists found out that a synthetic salicylic acid was easier to mass produce in pain killers, but synthetic salicylic acid is harder on the stomach. Those who take white willow bark for pain and fever do so because it appears that white willow bark is not as irritating to the stomach lining as aspirin. White willow bark may also have other beneficial compounds in addition salicin.

This particular bark has historically been used as an herb to relieve discomfort. Lately, it has been found to contain the natural pharmaceutically active compound salicin, or salicylic acid, the chemical forerunner of acetylsalicylic acid (modern aspirin) from which it is derived. Like its modern derivative aspirin, the natural chemical salicin from White Willow Bark is known to complement the body's ability to relieve discomfort, but without the possible complications and/or discomfort caused by aspirin. Thus where aspirin cannot be used, white willow bark has generally demonstrated effectiveness without aspirin-like side effects. Modern research has shown that its mechanism of actions is probably affected by inhibiting the neural transfer of pain signals.

Its pharmacological action is antipyretic, antiphlogistic and analgesic. It is often used for diseases accompanied by fever, rheumatic ailments, and headaches. Salicylic acid is known to block certain prostaglandin production, binding with them so as to inhibit adenosine, Prostaglandin E2 and phosphodiesterase that interfere with thermogenic action at beta-3 cell receptor sites. It can, therefore, also effectively increases or potentiate beta-3 cell receptor sites, allowing certain thermogenic amines (such as those found in Advantra-Z) to elicit thermogenic responses from brown fat cells (brown adipose tissue). Thus when used in combination with these amines and the theophyllines and related compounds found in green tea, weight loss, via thermogenesis, can occur!