Aspirin and Advil are both nonsteroidal anti-inflammatory drugs (NSAIDs) used to relieve pain, fever, and inflammation [2]. However, they work differently in the body. Aspirin is a salicylate that blocks the production of prostaglandins, which are responsible for pain and inflammation [1]. Advil, on the other hand, is a brand name for ibuprofen, which blocks the production of both prostaglandins and leukotrienes, which also contribute to pain and inflammation [2].

There is no evidence to suggest that aspirin counteracts the effects of Advil. However, taking both drugs together may increase the risk of side effects, such as stomach bleeding, ulcers, and kidney damage [2]. It is generally not recommended to take two NSAIDs together unless directed by a doctor [3].

It is important to follow the recommended dosage and duration of use for both aspirin and Advil. Aspirin should not be given to children under the age of 18 due to the risk of Reye's syndrome, a rare but serious condition that can affect the brain and liver [1]. Advil should not be taken by individuals with a history of stomach bleeding or ulcers, heart disease, or kidney disease, and should be used with caution in individuals over the age of 65 [2].

In conclusion, aspirin and Advil are both NSAIDs used to relieve pain, fever, and inflammation, but they work differently in the body. While there is no evidence to suggest that aspirin counteracts the effects of Advil, taking both drugs together may increase the risk of side effects. It is important to follow the recommended dosage and duration of use for both drugs and to consult a doctor before taking two NSAIDs together [1][2][3].

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/ASPIRIN
[2] https://my.clevelandclinic.org/health/drugs/11086-non-steroidal-anti-inflammatory-medicines-nsaids
[3] https://www.fda.gov/media/76636/download