Video: Does cough syrup really work?

What do you do when you have a bad cough? If you reach for the yummy, cherry-flavored cough medicine, you're not alone. Every year, people spend billions of dollars on these over-the-counter remedies. But do any of them work?

In this week's Reactions video, we explain the chemistry behind cough medicine, and dig into the evidence to find out which remedies actually work.