Advil does not contain aspirin; rather, it contains ibuprofen, according to Drugs.com. It is a nonsteroidal anti-inflammatory drug that combats pain by reducing inflammation anywhere present in the body.
Those with an allergy to aspirin or other nonsteroidal anti-inflammatory drugs should not take ibuprofen, as cautioned by Drugs.com. Heavy or long-term use of ibuprofen can result in stomach issues and liver damage. Seek immediate medical attention in the event of any symptoms indicative of damage to the stomach or liver. Less serious side effects include lethargy, headaches and stomach upset. Women in the last trimester of pregnancy should not take ibuprofen, and breastfeeding women should consult a physician before taking ibuprofen.