The Study
Povidone-iodine nasal spray (Nasodine®) for the common cold: a randomized, controlled, double-blind, Phase III clinical trial
This study is like a fair test where some people got the real nose spray and some got a fake one, and no one knew which they had. It shows the spray might help reduce cold symptoms in adults, but we can't be 100% sure because the main thing they were testing didn't clearly work better than the fake spray.
Analysis score
Maximum 90 for a randomized controlled trial.
Where the score came from
A special nose spray made some people with colds feel better faster, especially if they used it right when they got sick.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 572 / 100
Quality score
Participants are randomly assigned to treatment or control groups, minimizing bias. The gold standard for testing whether an intervention causes an effect.
Key takeaways
Summary
Based on the study abstract and findings.
- 1People felt noticeably better and could go about their day more easily.
- 2Spray reduced how bad colds felt by 12.6% and helped people do normal things 16.1% better.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Frontiers in Medicine
Year
2025
Authors
Thomas M. Polasek, Peter L. Friedland
Related Content
Claims (5)
This says that a nasal spray called Nasodine helps people with colds feel better in their daily lives. It claims that using Nasodine makes people 16% more comfortable compared to using a simple saltwater spray.
Nasodine is a medicine that's easy for adults to use. Some people get a little bit of nose discomfort that goes away quickly, but it doesn't cause any serious problems.
Using a povidone-iodine nose spray four times a day for 5 days might help reduce how bad a common cold feels by about 12.6% compared to a saltwater spray, but the results weren't quite strong enough to be sure.
If you take Nasodine medicine soon after you start feeling sick with a cold, it can make your symptoms much less severe. Getting treated early is really important for it to work well.
Using Nasodine spray doesn't really shorten how long a common cold lasts—it takes about 10 days to get better, just like using a simple saltwater spray.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.