The Effect of Zinc Acetate Lozenges on the Rate of Recovery From the Common Cold (HelZinki)
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ClinicalTrials.gov Identifier: NCT03309995 |
Recruitment Status :
Completed
First Posted : October 16, 2017
Last Update Posted : February 5, 2020
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A randomized parallel-group two arm superiority trial with an allocation ratio 1:1, both participants and investigators blinded.
The zinc lozenge that will be used in the study is a commercial product available from the University Pharmacy, Helsinki, Finland. The product is classified as a "medical device" and it is not regulated according to the jurisdiction for medicines.
Each lozenge contains 13 mg elemental zinc as zinc acetate. The instruction in the commercial package for common cold patients is to dissolve slowly 6 lozenges per day in their mouth, which totals to 78 mg/day of elemental zinc, at most for 5 days. The same instruction will be used in this trial.
The University Pharmacy prepared 200 placebo lozenge packages so that the placebo lozenges contain sucrose octaacetate, and they are similar with the zinc lozenges in visual appearance and in taste. 200 packages of zinc lozenges will be used as the active intervention. The packages will contain 30 lozenges (6 lozenges/day × 5 days).
The packages of lozenges will be distributed to the enrolled participants in November 2017. The participants will be instructed to keep the package readily available so that, when they catch the common cold, they will find the package and they can start to take the lozenges according to the instructions.
The participants will be instructed to start taking zinc lozenges as soon as they start to suffer from the first symptoms of the common cold. The participants will be instructed to take 6 lozenges daily over the time awake, evenly distributed, allowing the lozenge to dissolve in the mouth as slowly as possible. The duration of intervention is for the maximum of 5 days. If the symptoms disappear before 5 days, the participant may stop the usage of the lozenges.
There will be no limitations for other treatments that participants wish to use for treating their colds.
Participants will be requested to respond to a web-based symptom questionnaire daily from the first day of the treatment to the recovery from the common cold, or to a maximum of 2 weeks.
Condition or disease | Intervention/treatment | Phase |
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Common Cold Respiratory Tract Infections | Device: Lozenges Device: Placebo lozenges | Not Applicable |
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 87 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor) |
Primary Purpose: | Treatment |
Official Title: | The Effect of Zinc Acetate Lozenges on the Rate of Recovery From the Common Cold: a Randomized Trial |
Actual Study Start Date : | December 1, 2017 |
Actual Primary Completion Date : | April 24, 2018 |
Actual Study Completion Date : | September 24, 2018 |
Arm | Intervention/treatment |
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Experimental: Zinc lozenges
Each lozenge contains 13 mg elemental zinc as zinc acetate. The instruction for common cold patients is to dissolve slowly 6 lozenges per day in their mouth, which totals to 78 mg/day of elemental zinc, at most for 5 days, as early as possible from the start of the cold symptoms.
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Device: Lozenges
The participants will be instructed to take 6 lozenges daily over the time awake, evenly distributed, allowing the lozenge to dissolve in the mouth as slowly as possible. |
Placebo Comparator: Placebo lozenges
The placebo lozenges contain sucrose octaacetate, and they are similar with the zinc lozenges in visual appearance and in taste.
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Device: Placebo lozenges
Placebo lozenges |
- The duration of the common cold (time to recovery) [ Time Frame: 2 weeks after the start of the intervention ]Data of 12 common cold symptoms will be recorded by patients to web-based system, with scale 0: Absent, 1: Mild, 2: Moderately severe, 3: Very severe symptom. The symptom score is calculated as a sum over all the symptoms which means that the maximum of the symptom score scale is 3×12 = 36 points. Recovery from the cold is defined as the day when the symptom score is 0 or 1.
- Objective fever [ Time Frame: 2 weeks after the start of the intervention ]Measured fever (≥37.5°C any time during the day) (Yes / No)
- Sickness absence [ Time Frame: About 1 month after the start of the intervention ]Data will be collected of the absence from work after the start of intervention
- Usage of antibiotics and/or asthma medication [ Time Frame: About 1 month after the start of the intervention ]Data will be collected of the usage of antibiotics and/or asthma medication after the start of intervention
- Complications such as sinusitis, bronchitis, otitis. [ Time Frame: About 1 month after the start of the intervention ]Data will be collected of the occurrence of sinusitis, bronchitis, otitis after the start of intervention

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Ages Eligible for Study: | 18 Years to 70 Years (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
- ≥18 years, recollecting that they usually have had ≥1 colds per winter.
Exclusion Criteria:
- pregnancy or lactation; chronic runny nose or chronic cough.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT03309995
Finland | |
City of Helsinki | |
Helsinki, Finland |
Principal Investigator: | Harri Hemilä, MD, PhD | University of Helsinki |
Publications of Results:
Responsible Party: | Harri Hemilä, MD, PhD, Senior researcher, docent, University of Helsinki |
ClinicalTrials.gov Identifier: | NCT03309995 |
Other Study ID Numbers: |
HelZinki Study |
First Posted: | October 16, 2017 Key Record Dates |
Last Update Posted: | February 5, 2020 |
Last Verified: | January 2020 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | Yes |
Plan Description: | IPD reported with the trial report (2020) |
Time Frame: | Upon the publication of trial report indefinitely |
Access Criteria: | IPD reported with the trial report (2020) is freely available |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
Cough Laryngitis Pharyngitis |
Rhinitis Zinc Acetate Zinc Lozenge |
Respiratory Tract Infections Common Cold Infections Respiratory Tract Diseases |
Picornaviridae Infections RNA Virus Infections Virus Diseases |