The market for over-the-counter medicines to treat cold and cough was valued at over $9.5 billion in 2015 in the United States alone, with several more billions spent on treating this common ailment around the world. And this, despite the fact that a report compiled by Drug Store News in February 2016 said the incidence of flu across the country was down 10.7 percent in the last three months of 2015.

Given the large size of the industry, referred to by Drug Store News as “one of the most strategically important categories in retail pharmacy,” it is only natural to ask: Does cough medication actually work?

The American Chemical Society (ACS), a nonprofit chartered by the U.S. Congress, analyzed both the chemistry behind cough medicines and data from previous research into the efficacy of those medicines, and published its findings in video format Tuesday.

In the video, part of its “Reactions” series, ACS said it looked at a few systematic reviews which themselves analyze the evidence from multiple studies asking the same question.

And the conclusion ACS reached was: “There is very little evidence that cough syrup is effective at treating coughs. And carefully performed clinical trials show that these medications are generally no better than a placebo. In one review, 15 out of 19 studies analyzed either showed no benefits or the results were conflicting. Other reviews had similar findings.”

Cough medication has come a long way since the 19th century, when it often included alcohol, cannabis, chloroform, morphine and even heroin. ACS called the active ingredients in today’s cough medicines “more reasonable.” These ingredients include chemicals that are designed for specific tasks: blocking the cough reflex, loosening and thinning the mucus in the lungs, decongesting the lungs and the nose, reducing the swelling of the throat and the nose, and so on.

According to the Drug News Store report, cough syrup sales were worth almost $580 million in 2015. While there is no guarantee the active ingredients in the syrups will cure your cough, some of them will help you get a good night’s sleep though. But large doses can lead to serious health complications, and even death. Cough medication is especially dangerous for young children, ACS warned, citing the evidence of thousands of children aged 12 or less being taken to emergency rooms every year because of cough medicine overdoses.

ACS suggests some other non-medical remedies that could help deal with a cough. Drink plenty of fluids, and suck on cough drops or any other hard candy. And if nothing helps, don’t worry, because a regular cough will go away on its own in a week or two.