See the DrugPatentWatch profile for advil

Based on the information available, there isn't a specific "common delay" for Advil (ibuprofen) to alleviate headaches, as the onset of pain relief can vary from person to person. Generally, ibuprofen is absorbed quickly by the body, with peak concentrations occurring within 1-2 hours after oral administration [1]. However, the time it takes for an individual to experience headache relief may be influenced by various factors such as the severity of the headache, the dosage taken, and the individual's sensitivity to ibuprofen. It is always recommended to follow the dosage instructions provided by a healthcare professional or those listed on the packaging.

Sources:
[1] https://drugpatentwatch.com/ibuprofen/