Effective treatment for the common cold have been difficult to develop because so many different types of virus are responsible for this condition. Oral zinc has been studied as a possible means of preventing or alleviating symptoms, with mixed results. We studied a new approach to zinc therapy--an over-the-counter nasal gel formulation (Zicam)--to independently evaluate its efficacy as a treatment for the common cold. Our study was conducted at four sites over a 5-month period. The study group consisted of 213 patients with recent-onset(< or = 24) cold symptoms; 108 patients received zinc therapy, and 105 reviewed placebo. Symptom charts were used to track the duration and severity of each patient's symptoms. At study's end, the duration of symptoms was 2.3 days (+/-0.9)in the zinc group and 9.0 days (+/-2.5)in the control group--a statistically significant difference (p <0.05). These results provide evidence that zinc nasal gel is effective in shortening the duration of common cold symptoms off when taken within 24 hours of their onset.