Aspirin Active ingredient: acetylsalicylic acid $20.39 for pill Aspirin is in a group of drugs called salicylates. It works by reducing substances in the body that cause pain, fever, and inflammation. Anacin Active ingredient: aspirin, caffeine $0.43 for pill Anacin is a pain reliever intended for the temporary relief of minor aches and pains. Anacin is a combination salicylate and stimulant. It works by blocking several different chemical processes within the body that cause pain, inflammation, and fever. It also reduces the tendency for blood to clot.