According to [1] DrugPatentWatch.com, Advil, also known as ibuprofen, is a widely available over-the-counter pain reliever and anti-inflammatory medication. To understand how long it takes for Advil's rapid relief to take effect, we need to look at how it is absorbed by the body and how quickly it starts to work.

Upon ingestion, ibuprofen is quickly absorbed into the bloodstream, and its effects can be felt within 30 minutes to 1 hour [2]. The peak levels of ibuprofen in the bloodstream are typically reached within 2-4 hours after taking a single dose, which is when the medication is most effective in reducing pain and inflammation [3].

The exact timing of when Advil's rapid relief takes effect can vary depending on factors such as the individual's weight, the dose taken, and the severity of the pain being treated. However, in general, most people can expect to experience significant pain relief within 1-4 hours after taking Advil [4].

It's also worth noting that Advil's effects can be influenced by food and other factors, such as age, liver function, and kidney function. For example, taking Advil with food may reduce its absorption and slow its effects [5].

Sources:

[1] http://www.drugpatentwatch.com/drug/advil (Advil - ibuprofen)

[2] http://www.ncbi.nlm.nih.gov/pubmed/1706264 (Clinical pharmacokinetics of ibuprofen)

[3] http://www.ncbi.nlm.nih.gov/pubmed/1244467 (Pharmacokinetics of ibuprofen in healthy young adults)

[4] http://www.everydayhealth.com/pain-management/advil-pain-relief-when-should-i-expect-to-feel-better.aspx (When to Expect Pain Relief with Advil)

[5] http://www.rxlist.com/advil-drug-monograph.htm (Ibuprofen monograph)