The calendar might not acknowledge it, but we're deep into cold and flu season. If you've been feeling the wrath of the common cold, you've probably reached for that old standby: cough syrup. A quick glance at cough syrup's claims lead you to believe that after a teaspoon or two, you'll be feeling some sweet relief, but according to the American Chemical Society, these medications might not be doing much for your cough. There are a few types of cough syrup and they work in different ways. Antitussive drugs (dextromethorphan, a.k.a. DM or DXM) block the cough reflex. Expectorants thin mucus, making it easier to cough. Decongestants open your airways by narrowing the blood vessels. Antihistamines can reduce nose-and-throat swelling. Sounds good, right? In studies performed by the ACS, these drugs actually didn't perform any better than a placebo. In a video , the ACS explains that "this is one of those more-research-is-needed type situations." What the studied do conclude, however, is that over-the-counter cough medication can make you drowsy, which can help you sleep if that persistent cough is keeping you up. In fact, rest is the one thing that really can help your cough. In addition to taking it easy and catching those ZZZs, the ACM suggests staying hydrated with plenty of fluids, using a humidifier, or popping some sort of hard candy. That's right, cough drops don't do much, either. What's next? Are they going to tell us that unicorns aren't real? (Spoiler: They're not, but they sure are fun .)