--- title: "Evidence: catalytic/structural cofactor, immunity" description: "Zinc may shorten the duration of common cold symptoms if taken early at a dose of ≥ 75 mg/day, but it can cause side effects like bad taste and nausea." url: "https://magellanlongevity.com/study/s133.md" canonical: "https://magellanlongevity.com/study/s133.html" html: "https://magellanlongevity.com/study/s133.html" type: "study" study_key: "s133" journal: "Cochrane Database Syst Rev" year: 2013 pmid: "23775705" doi: "10.1002/14651858.CD001364.pub4" citations: 1 updated: 2026-09-02 author: "Gabriel Radu, DO" author_credentials: "Physiatrist (PM&R). NY medical license 275110. NPI 1376861765." publisher: "Magellan Longevity" content_format: "markdown" --- # Evidence: catalytic/structural cofactor, immunity [Home](https://magellanlongevity.com/) › [Research map](https://magellanlongevity.com/longevity-research-map.html) › Evidence: catalytic/structural cofactor, immunity **HTML version:** https://magellanlongevity.com/study/s133.html · **In the Magellan app:** https://magellanlongevity.com/#/study/s133 ## Citation | Field | Value | | --- | --- | | Journal | Cochrane Database Syst Rev | | Year | 2013 | | PMID | [23775705](https://pubmed.ncbi.nlm.nih.gov/23775705/) | | DOI | [10.1002/14651858.CD001364.pub4](https://doi.org/10.1002/14651858.CD001364.pub4) | | Study key | s133 | ## Takeaway Zinc may shorten the duration of common cold symptoms if taken early at a dose of ≥ 75 mg/day, but it can cause side effects like bad taste and nausea. ## The question Is zinc effective in reducing the incidence, severity, and duration of common cold symptoms, and what are the potential sources of heterogeneity in study results? ## Hypothesis The study aims to assess the efficacy of zinc in reducing common cold symptoms and identify factors influencing study outcomes. ## Methods This updated systematic review searched multiple databases for randomized, double-blind, placebo-controlled trials. Trials included used zinc for at least five consecutive days for treatment or five months for prevention of the common cold. Two authors independently extracted data and assessed trial quality. ## Results The review included 16 therapeutic trials (1387 participants) and two preventive trials (394 participants). Zinc intake was associated with a significant reduction in the duration of common cold symptoms (mean difference -1.03 days) and a smaller proportion of participants symptomatic after seven days (odds ratio 0.45). The incidence rate of developing a cold (IRR 0.64), school absence, and antibiotic prescriptions were lower in the zinc group. However, zinc was not associated with a significant reduction in symptom severity. Adverse events, including bad taste (OR 2.31) and nausea (OR 2.15), were higher in the zinc group. High heterogeneity was observed across results. ## Conclusion Zinc administered within 24 hours of symptom onset reduces the duration of common cold symptoms in healthy individuals, but data heterogeneity requires caution. For treatment, zinc lozenges at a dose of ≥ 75 mg/day are suggested. No firm recommendation can be made for prophylactic zinc due to insufficient data. The benefits of zinc lozenges must be weighed against side effects like bad taste and nausea. ## Limitations The very high heterogeneity across the included studies means that the averaged estimates should be viewed with caution. Insufficient data prevented a firm recommendation for prophylactic zinc supplementation. ## Verbatim from the abstract > zinc was associated with a significant reduction in the duration of common cold symptoms ## Impact of Zinc on Common Cold Symptoms and Side Effects | Measure | Mean Difference or Odds Ratio | | --- | --- | | Duration of Cold (days) | -1.03 | | Symptomatic after 7 days (OR) | 0.45 | | Incidence of Cold (IRR) | 0.64 | | Overall Adverse Events (OR) | 1.58 | | Bad Taste (OR) | 2.31 | | Nausea (OR) | 2.15 | *Zinc significantly reduced the duration of common cold symptoms and the proportion of symptomatic individuals after 7 days, as well as the incidence of colds. However, it also increased the occurrence of overall adverse events, bad taste, and nausea.* ## Where this study is used on Magellan This paper is one of the citations behind the evidence grade on the pages below. Grades are assigned from the published research and are independent of affiliate commissions. | Compound or device | Evidence grade | Graded pages | | --- | --- | --- | | Zinc Picolinate | Moderate evidence | [Zinc Picolinate](https://magellanlongevity.com/p/133.md) | ## Reference 1. **Evidence: catalytic/structural cofactor, immunity** Cochrane Database Syst Rev 2013 · [PMID 23775705](https://pubmed.ncbi.nlm.nih.gov/23775705/) · [DOI 10.1002/14651858.CD001364.pub4](https://doi.org/10.1002/14651858.CD001364.pub4) > zinc was associated with a significant reduction in the duration of common cold symptoms ## Structured data ```json {"@context":"https://schema.org","@graph":[{"@type":"MedicalWebPage","@id":"https://magellanlongevity.com/study/s133.html#page","url":"https://magellanlongevity.com/study/s133.html","name":"Evidence: catalytic/structural cofactor, immunity","description":"Zinc may shorten the duration of common cold symptoms if taken early at a dose of ≥ 75 mg/day, but it can cause side effects like bad taste and nausea.","inLanguage":"en","isPartOf":{"@type":"WebSite","name":"Magellan Longevity","url":"https://magellanlongevity.com/"},"author":{"@type":"Person","name":"Gabriel Radu, DO","jobTitle":"Physiatrist (PM&R)","identifier":[{"@type":"PropertyValue","name":"NPI","value":"1376861765"},{"@type":"PropertyValue","name":"NY medical license","value":"275110"}]},"publisher":{"@type":"Organization","name":"Magellan Longevity","url":"https://magellanlongevity.com/"},"encoding":{"@type":"MediaObject","encodingFormat":"text/markdown","contentUrl":"https://magellanlongevity.com/study/s133.md"},"dateModified":"2026-09-02"},{"@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://magellanlongevity.com/"},{"@type":"ListItem","position":2,"name":"Research map","item":"https://magellanlongevity.com/longevity-research-map.html"},{"@type":"ListItem","position":3,"name":"Evidence: catalytic/structural cofactor, immunity","item":"https://magellanlongevity.com/study/s133.html"}]},{"@type":"ScholarlyArticle","@id":"https://magellanlongevity.com/study/s133.html#study","name":"Evidence: catalytic/structural cofactor, immunity","headline":"Evidence: catalytic/structural cofactor, immunity","datePublished":"2013","isPartOf":{"@type":"Periodical","name":"Cochrane Database Syst Rev"},"identifier":"PMID:23775705","url":"https://pubmed.ncbi.nlm.nih.gov/23775705/","sameAs":"https://doi.org/10.1002/14651858.CD001364.pub4","abstract":"Zinc may shorten the duration of common cold symptoms if taken early at a dose of ≥ 75 mg/day, but it can cause side effects like bad taste and nausea."}]} ``` ## Related on Magellan Longevity - [Zinc Picolinate](https://magellanlongevity.com/p/133.md) — product graded on this and related evidence - [The Effect of a Multivitamin and Mineral Supplement on Immune Function in Healthy Older…](https://magellanlongevity.com/study/d32823974.md) - [Effect of Zinc Supplementation in Children on Diarrhea Attacks: A Randomized Controlled…](https://magellanlongevity.com/study/d35747897.md) - [Longevity research map](https://magellanlongevity.com/longevity-research-map.html) - [Evidence-based longevity supplements](https://magellanlongevity.com/longevity-supplements.md) ## Scope and disclosures Educational information, not medical advice. Nothing here is intended to diagnose, treat, cure, or prevent any disease. Talk to your physician before starting any supplement or device, especially if you are pregnant, nursing, or taking medication. Editorial firewall: evidence grades are assigned from the published research and are independent of any affiliate commission. As an Amazon Associate, Magellan Longevity earns from qualifying purchases. Reviewed for accuracy by a board-certified physician (DO).