Is it safe to take expired Adderall?

Although there are no severe health issues with expired aspirin, it may cause stomach irritation or pain, and have a reduced potency. If possible, you should discard any expired aspirin and buy a new bottle.

Aspirin is a relatively stable compound that does not break down readily in dry air, but over time contact with moisture will break it down into acetic and salicylic acids. A purported chemist on Epinions.com mentions that aspirin was inspired by the traditional use of salicylic acid extracted from willow bark to reduce pain and inflammation, but this often damaged the mucous membranes of the mouth and esophagus, and caused hemorrhaging of the stomach lining.

Pharmaceutical scientists discovered that by modifying the compound slightly, they could produce a safer form of the acid called acetylsalicylic acid that did not cause any damage. However, very old aspirin can break down into salicylic acid and thus cause irritation of the stomach. This is normally accompanied by a vinegar-like odour from the bottle when you open it.