Advil is a brand name for ibuprofen, a nonsteroidal anti-inflammatory drug (NSAID) used to treat pain, fever, and inflammation. The dosage of Advil depends on the individual's age, weight, and medical condition. According to the Advil website [2], the recommended dosage for adults and children over 12 years of age is 200-400 mg every 4-6 hours, not to exceed 1200 mg in 24 hours. Children under 12 years of age should consult a doctor before taking Advil. It is important to follow the recommended dosage and not exceed the maximum daily dose to avoid potential side effects such as stomach bleeding, liver damage, and kidney problems [3]. Additionally, patients should consult their doctor or pharmacist before taking Advil if they have a history of heart disease, high blood pressure, asthma, or stomach ulcers, or if they are taking other medications that may interact with Advil [3].

Sources:
[2] https://www.advil.com/faqs-en/advil-pain/
[3] https://www.drugs.com/advil.html