Along with various polyphenols, willow bark contains salicin. Salicin is a type of alcohol that contains a compound called β-glucoside. When you consume it, your body breaks it down into two parts: glucose and salicyl alcohol. The alcohol is then converted into salicylic acid through a process called oxidation.
Salicylic acid may be effective in reducing the production of prostaglandins, which cause inflammation and pain in the body.
In fact, salicylic acid is the most basic form of a group of chemicals known as salicylates. This is why it may he properties similar to aspirin, which breaks down quickly in the body into salicylic acid.
Historically, Native Americans chewed willow bark to relieve pain. Today, people may use willow bark to treat conditions like back pain, osteoarthritis, or muscle aches. It’s often found as an ingredient in various supplements.
That said, there’s still limited scientific evidence to support its effectiveness in treating these ailments.
Here’s what the research says:
ArthritisIn a 2023 research review looking at 329 patients with different types of arthritis, researchers found that people who used willow bark had more symptom relief than those who took a placebo.
But in older research examining the effects of willow bark extract on people with osteoarthritis (OA) and rheumatoid arthritis (RA), they found inconclusive results.
Some studies found no difference in pain relief compared to a placebo or medication, while others showed minor improvements that did not reach statistical significance.
It’s worth noting that most types of arthritis are inflammatory conditions. When it came to studies on pain caused by musculoskeletal conditions like osteoarthritis or general back pain, researchers found more improvement in pain with mild to minimal side effects in most cases.
In these cases, the differences in findings may he been related to the specific formulation, the type of willow bark, or the dose.
Antimicrobial propertiesA 2021 study suggests that two willow bark extracts may he significant anti-inflammatory effects on strings of amino acids called peptides and inflammatory cells produced by COVID-19.
Yet more research is needed to understand whether this means willow bark can actually reduce viral inflammation, such as fever.
In another 2021 study, researchers examined 16 different types of northern willow trees to see how they could be used for natural products using a gentle hot water extraction technique.
The results found that all types may he antiviral effects against viruses such as coxsackievirus A9 and bacteria like Staphylococcus aureus and Escherichia coli (E. coli). They didn’t appear to be as effective against fungi.
The findings weren’t exactly the same depending on the type of bark, and more research is necessary to replicate these findings in people.
Skin agingA 2024 test-tube study looked at certain polyphenols found in a type of willow bark, Salix chaenomeloides, on human skin cells.
The results suggest the potential for reducing skin aging from sun damage and inflammation while promoting antioxidant activity, though clinical studies on human subjects are needed to verify this finding.
Weight lossWillow bark is often an ingredient in dietary supplements — which are not regulated by the FDA.
In fact, there’s very limited evidence that the plant is effective in this space. More research is needed to determine the effect of any species of willow bark on human weight.