Please don't take Advil before long runs. Advil is taxing on your kidneys and so is endurance running. The combination of both can lead to a trip to the ER or even death if you're unlucky.

Whether it actually helps reduce injuries and pain is also somewhat questionable according to a recent 538 article[0].

[0] http://fivethirtyeight.com/features/the-achiness-of-the-long...