The therapeutic properties of white willow bark have been known throughout Europe and Asia for millennia. Willow bark tincture is mentioned in ancient Middle Eastern and Greek texts and legend has it Hippocrates recommended it for relieving headaches. He might smile to know modern research supports what he knew all those centuries ago: white willow bark extract has analgesic antipyretic and anti-inflammatory properties.

The active compound in white willow bark is salicin a purified metabolite of which is acetylsalicylic acid the active ingredient in aspirin. In fact the name salicylic acid as well as the word salicylates come from the botanical name for white willow Salix alba. White willow bark also contains various flavonoids and polyphenols which may work in concert with salicin to potentiate the beneficial effects. Salicin is actually a prodrug and the salicylic acid metabolite is responsible for the analgesia.

In modern times the beneficial effects of willow bark were first noted by a British researcher in the mid-1700s and salicylic acid was first isolated by a German chemist in 1827. (This study provides a succinct but fascinating history of the discoveries behind the medicinal properties of willow bark and the development of aspirin.)

There is reliable evidence to support willow bark’s efficacy for many of the same ailments for which people frequently rely on aspirin. However owing to its other constituent compounds willow bark has therapeutic properties beyond those of aspirin and it is not known to cause the gastrointestinal damage that may result from aspirin. One paper explained that salicylic acid concentrations in the body after ingesting an analgesic dose of aspirin are orders of magnitude higher than what could reasonably be obtained from willow bark so the noted potency of the natural substance is likely due to interactions and synergies between the salicin and multiple other compounds.

With the FDA strengthening its warnings about harmful side-effects of aspirin and other NSAIDs patients and medical practitioners alike may be looking for a safer but still efficacious alternative. Willow bark may be helpful for headaches low back pain osteoarthritis fever menstrual cramps tendonitis and more. Although willow bark brings far fewer side-effects than aspirin individuals who are allergic or sensitive to salicylates should avoid willow bark and caution should be used when recommending willow bark to patients who are already taking NSAIDs diuretics beta-blockers and anticoagulants. According to a Cochrane review willow bark reduces low back pain more than placebo although the authors reported that the evidence was “of moderate quality at best.” 

Beyond its aspirin-like effects willow bark—the salicin specifically—has been shown to have some interesting properties related to angiogenesis and tumor progression. First salicin has antioxidant effects which may be helpful for any condition associated with oxidative stress. (Is there a condition that isn’t?) Additionally salicin decreased expression of vascular endothelial growth factor and inhibited angiogenesis and tumor growth in mice. One study’s authors concluded that salicin may be “a potent therapeutic agent for hypervascularized tumors.”

Salicyclic acid is an ingredient in many over-the-counter topical products for acne and overall skin health. Research indicates salicin administered topically may be helpful for improving the visible signs of aging. In a study involving 30 female subjects (ages 35-70) showing mild to moderate signs of aging twice daily facial application of a serum containing 0.5% salicin for twelve weeks resulted in improvements in wrinkles tactile roughness pore size radiance and overall appearance after just one week. By week four improvements were noted in mottled pigmentation global firmness and jaw-line contour. There were no adverse incidents or tolerability issues reported. So perhaps beauty products containing salicin salicylic acid and other compounds from willow bark might earn their keep in the medicine chest from the teenage years on through the golden years.