White Willow Bark
Salix alba
Also known as: Willow Bark, European Willow
Overview
The original aspirin: salicin was isolated from willow bark in 1828 and set chemists on the path to acetylsalicylic acid. Willow bark delivers far less salicylate than an aspirin tablet, and in trials the benefit builds over days rather than in a single dose. That lower dose is likely why it seems gentler on the stomach — but it has never been tested head-to-head against aspirin for stomach injury in people, so treat that as plausible, not proven. It is still a salicylate: avoid it if you are allergic to aspirin, and check with your doctor if you take a blood thinner.
Proposed mechanism
Salicin is converted to salicylate in the gut and liver, inhibiting COX-1 and COX-2 prostaglandin synthesis. Polyphenol fraction provides additional anti-inflammatory mechanisms independent of salicylates.
Mechanisms describe how researchers think a compound may act, often from laboratory work — a proposed mechanism is not proof of a clinical effect in people.