Saline nose drops may shorten colds and cut transmission, trial hints

For centuries, the common cold has eluded effective treatments — but now, a study hints that simple nose drops may help subdue the virus, shortening symptoms by days and reducing the likelihood of spread to others.

The nose drops contain just two ingredients: water and salt. The solution is known as "hypertonic saline," meaning it contains a higher concentration of salt than is typically found in bodily fluids.

"We presume that the impact of the hypertonic saline drops was to reduce viral loads," or the amount of virus in the body, said study co-author Dr. Steve Cunningham, a professor of pediatric respiratory medicine at the University of Edinburgh.

The team didn't test this idea directly, but "it is commonly understood that higher viral loads have a greater capacity for transmission," he said.

Related: When did humans start getting the common cold?

Cutting the length and transmission of colds by even a little could have big impacts, Cunningham added. The average adult experiences two to four colds per year, but these numbers are about twice as high in children, in part because they have yet to build immunity to the more than 200 cold-causing viruses. These illnesses are typically mild but can sometimes lead to severe complications.

And even mild colds come at a cost — doctor visits can be inconvenient and costs of treatments add up, especially if the illness results in missed work or school time.