Though pharmaceutical companies contacted by PopSci wouldn't share their marketing secrets, you can still derive a drug's molecular and popular heritage just by studying its name. Like, for example, Tylenol. Its chemical name is N-acetyl-p-aminophenol--see the tyl and -ol in there? Then there's Viagra. It doesn't sound like sildenafil, but it certainly suggests vigor and virility--exactly what Pfizer wants you to think. Xeljanz, which was approved earlier this year after almost 20 years of research, targets a protein called Janus kinase. It works in a different cellular pathway from other arthritis drugs. That's where you get the -jan part of that name, which, to someone with a drug decoder, connotes its uniqueness.