The Claim

In euthyroid adults with cold symptoms, a 0.5% povidone-iodine nasal spray (Nasodine) administered four times daily for 5 days reduces overall common cold severity by 12.6% compared to saline nasal spray, as measured by the Global Severity Score (GSS), though this did not reach statistical significance (p=0.054) in the intention-to-treat population.

Source: Povidone-iodine nasal spray (Nasodine®) for the common cold: a randomized, controlled, double-blind, Phase III clinical trial

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
72score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Cause and effect
1 study reviewed
In plain English

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.

See the scientific wording

A 0.5% povidone-iodine nasal spray (Nasodine) administered four times daily for 5 days reduces overall common cold severity by 12.6% compared to saline nasal spray in euthyroid adults with cold symptoms, as measured by the Global Severity Score (GSS), though this did not reach statistical significance (p=0.054) in the intention-to-treat population.

What the research says

1 study
  1. Study: Povidone-iodine nasal spray (Nasodine®) for the common cold: a randomized, controlled, double-blind, Phase III clinical trial

    The study tested the exact same nose spray and found it reduced cold symptoms by 12.6% compared to saltwater spray, just like the claim said, though it wasn't quite strong enough proof to be sure it wasn't just chance.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

Fit Body Science verdict — we translate health claims into clear verdicts backed by peer-reviewed research.

Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.

Does povidone-iodine nasal spray reduce common cold severity compared to saline spray? | Scientific Fact Check | Fit Body Science