Aspirin works by blocking the production of prostaglandins, the on-off switch in cells that regulate pain and inflammation, among other things. That's why aspirin stops mild inflammation and pain.

How does aspirin work in the body?

Aspirin works to prevent the platelets in your blood from clumping and clotting in your arteries, thereby reducing these risks by improving blood flow to your heart and brain. Aspirin is the only OTC pain reliever known to have these lifesaving benefits.

How does aspirin work as blood thinner?

Aspirin slows the blood's clotting action by making platelets less sticky. Platelets are blood cells that stick together and block cuts and breaks in blood vessels, so they're important in normal health.