Advil, which contains ibuprofen, generally takes about 20 to 30 minutes to start working for pain relief. The maximum pain relief effect typically occurs within 1 to 2 hours after taking it. The effects of Advil usually last for 4 to 6 hours. Taking it on an empty stomach may lead to faster relief, but it can increase the risk of stomach irritation. The timing can vary depending on factors like the dosage, individual health, and whether it is taken with food.