Zinc Spray Shortens Colds
Duration Slashed Up to Half in Those Who Began Treatment Within 48 Hours
WebMD News Archive
Jan. 7, 2003 -- New research suggests that the length and severity of a cold may be cut in half when treatment with a zinc nasal spray is started within two days of the onset of symptoms.
In previous studies that showed relief from the use of such zinc sprays, significant relief was achieved only when these products were used within the first 24 hours of the first signs of sniffling, congestion, hoarseness, and sore throat, says study researcher Sherif B. Mossad, MD, FACP, FIDSA, of The Cleveland Clinic.
"No one really knows why zinc works, but there are several theories," he tells WebMD. "My feeling, and the leading theory, is that the zinc blocks the cold virus from combining with surface proteins that trigger symptoms."
In his study, published in the January issue of the medical journal QJM: An International Journal of Medicine, patients using Zicam, an over-the-counter nasal spray, cut the length of their colds an average of 1.5 days compared with those treated with a placebo. However, some patients slashed their cold duration in half -- from six days to only three.
The study was paid for by the makers of Zicam, a spray that sells for about $10 and is available at most drug stores.
This study, which involved 80 patients who were in their first two days of a new cold, is now the sixth to show that colds could be shorter and less severe when using over-the-counter products containing zinc, says Mossad, an infectious diseases specialist. But eight other published studies showed no benefit from using these products. Three of those trials showing relief involved the use of nasal sprays, and one has shown use of the spray could halve a cold's duration, but only when taken in the first day of illness.
"The spray contains the same type of zinc gluconate that is in lozenges [such as Cold Ease], but I cannot say whether there is an advantage of using a spray administered in the nose over something that is put in the mouth," he tells WebMD. "I think it's a matter of personal preference. I've tried both and think that people could probably consider one of them to shorten the length of a cold. But theoretically, a spray might be better because colds originate in the nose and eyes, so if you take action at the point of entry, I would think that might be an advantage."
His study did not compare the benefit of sprays vs. lozenges.
The finding did not surprise Sabrina Sobel, PhD, of Hofstra University, a researcher who co-authored several papers examining how zinc lozenges affect cold symptoms and duration.
"In our studies, the best benefit came when the lozenges were taken within 24 hours of the first sign of symptoms, cutting colds by almost in half," she tells WebMD. "If you take zinc lozenges within 48 hours, there was some relief, but not as dramatic -- it cut cold duration by only about one-third."