"What the difference is between Aspirin, Acetaminophen, and Ibuprofin. What are the pros and cons of each drug and in what circumstances should I use one over the other?"
Aspirin (acetylsalicylic acid) is an NSAID (non-steroidal anti-inflammatory drug). It is more selective for the enzyme that thins your blood (COX-1) than the one that relieves pain (COX-2). Therefore, it is more often used as prevention for heart attack/stroke (but only your doctor tells you to).
Ibuprofen (Advil) is also an NSAID. However, it mostly works on COX-2, so it does less blood thinning. It is often preferred for pain relief because it has fewer side effects than other NSAIDs (it can have some stomach upset, take it with food to help this). In general, it is pretty safe, unless you take it every day, have kidney problems, or are over the age of 65.
Acetaminophen (Tylenol) is not an NSAID, but it works in a similar way. It is often used for lowering fevers, especially in children. While it is extremely safe at low doses, it can be SUPER DANGEROUS to your liver if you go above 3-4 grams (FYI tablets usually come in 325 mg, extra strength tablets are 500 mg).
DO NOT TAKE TYLENOL WHILE/AFTER DRINKING ALCOHOL. Alcohol takes away an enzyme that turns Tylenol into something safe, so it has to go through a different pathway and becomes something really dangerous to your liver. If you are hung over, use ibuprofen instead.
TL;DR Why don’t you take aspirin to pick up girls with you? Because it’s a cox blocker.
Eminem and Rihanna performing The Monster at the MTV Movie Awards 2014
(Source: eminem-era, via emineming)