Advil is a brand name for the drug ibuprofen, which is a nonsteroidal anti-inflammatory drug (NSAID) used to relieve pain, fever, and inflammation. According to Drugs.com [3], the recommended dosage for adults is 200 to 400 milligrams of ibuprofen every four to six hours as needed. However, the maximum daily dose should not exceed 1,200 milligrams. It is important to follow the recommended dosage and not exceed the maximum daily dose to avoid potential side effects such as stomach bleeding, kidney problems, and liver damage.

The Advil website [2] advises that users should wait at least four hours before taking another dose of Advil. This is consistent with the recommended dosage mentioned above. However, it is important to note that the frequency of taking Advil should not exceed the maximum daily dose.

DrugPatentWatch [1] provides information on the patent status of Advil and its generic versions. This information is not directly related to the question of how long to wait before taking another dose of Advil.

In summary, based on the provided sources, it is recommended to wait at least four hours before taking another dose of Advil. However, it is important to follow the recommended dosage and not exceed the maximum daily dose to avoid potential side effects.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/ADVIL
[2] https://www.advil.com/faqs-en/advil-pain/
[3] https://www.drugs.com/medical-answers/how-often-can-you-take-ibuprofen-3016181/