The common cold is one of the most frequent viral infections in humans. Although benign, its symptoms result in economic burden and can lead to severe or even fatal complications in children, elderly and groups with comorbidities. The main purpose of the treatment is the relief of symptoms; however, the medication is often associated with adverse effects. Iota-carrageenan is a polysaccharide that reveals antiviral activity by binding to viruses, inhibiting its replications and, consequently, its viral propagation. This systematic review of the literature aims to compare the effectiveness of an iota-carrageenan nasal spray to placebo. This systematic review was conducted through research in Cochrane Database, PubMed, Science Direct, SpringerLink, Oxford Journals, Elsevier, ClinicalKey, Wiley Online Library, Embase databases, in order to collect randomized and controlled clinical trials. In total, the research provided four articles regarding clinical trials for comparing iota-carrageenan nasal spray with placebo. The results show it has potent antiviral activity compared to placebo and  a favorable safety profile. Although further research is needed, the concept of a physical barrier capable of reducing viral penetration of epithelial cells in the nasal mucosa is appealing, and could lead to alternative approaches, with positive impact on global health.


carrageenan, iota-carrageenan, common cold, safe treatment, antiviral