Aspirin and Advil are both pain relievers, but they are not interchangeable. Aspirin is a nonsteroidal anti-inflammatory drug (NSAID) that is used to reduce pain, inflammation, and fever. Advil is the brand name for ibuprofen, another NSAID that is used for the same purposes as aspirin [3].

However, there are some differences between the two medications. Aspirin is more effective at reducing inflammation, while ibuprofen is better at relieving pain [2]. Aspirin can also cause stomach irritation and bleeding, especially when taken in high doses or for long periods of time [1]. In contrast, ibuprofen is less likely to cause stomach problems, but it can cause other side effects such as headaches, dizziness, and allergic reactions [3].

It is important to note that aspirin should not be used in place of Advil without consulting a healthcare provider. Aspirin can interact with other medications and medical conditions, and it is not recommended for everyone [1]. Advil may be a better choice for some people, especially those with stomach problems or allergies to aspirin [2].

In conclusion, while aspirin and Advil are both NSAIDs that can be used to relieve pain, inflammation, and fever, they are not interchangeable. Aspirin is more effective at reducing inflammation but can cause stomach irritation and bleeding, while ibuprofen is better at relieving pain and is less likely to cause stomach problems. It is important to consult a healthcare provider before switching from one medication to another [1][2][3].

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/ASPIRIN
[2] https://blog.walgreens.com/health/pain-management/acetaminophen-vs-aspirin-vs-ibuprofen.html
[3] https://www.drugs.com/medical-answers/difference-between-aspirin-ibuprofen-3508521/