Advil Liqui-Gels is a nonsteroidal anti-inflammatory drug (NSAID) used to relieve pain and reduce fever. According to Drugs.com [2], Advil Liqui-Gels can be taken with or without food. However, WebMD [3] suggests taking it with food or milk if it upsets your stomach. NSAIDs can cause stomach irritation and bleeding, especially if taken on an empty stomach or for a long time. Therefore, it is advisable to follow the dosage instructions on the package and consult a doctor before taking Advil Liqui-Gels on an empty stomach if you have a history of stomach problems. Additionally, Drug Patent Watch [1] shows that the patent for Advil expired in 2001, and there are now generic versions available. It is important to read the label and verify the active ingredient before taking any medication.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/ADVIL
[2] https://www.drugs.com/cdi/advil-liqui-gels.html
[3] https://www.webmd.com/drugs/2/drug-94173/advil-liqui-gel-oral/details