Does Cold-Eeze Work?
Yes, Cold-Eeze (zinc gluconate lozenges) is effective for reducing the duration of cold symptoms, but only when taken at doses ≥75 mg/day within 24 hours of symptom onset and continued throughout the illness. 1, 2
Evidence-Based Recommendation
Zinc lozenges containing zinc acetate or zinc gluconate at ≥75 mg/day significantly reduce the duration of the common cold when started within 24 hours of symptom onset. 1, 2 This recommendation comes from Level Ia evidence (highest quality systematic reviews) in the European Position Paper on Rhinosinusitis and Nasal Polyps 2020. 1
Critical Dosing Requirements
- Minimum effective dose: ≥75 mg of elemental zinc per day 1, 2
- Timing: Must begin within 24 hours of symptom onset 1, 2
- Duration: Continue throughout the entire cold (not just 1-2 days) 1
- Formulation: Zinc acetate or zinc gluconate lozenges specifically 1, 2
Expected Benefits vs. Side Effects
Benefits: Zinc reduces cold duration by approximately 3-4 days (from median 7-9 days to 4-5 days in clinical trials). 3, 4 The treatment specifically shortens cough duration (median 3.1 vs 6.3 days), nasal discharge (4.1 vs 5.8 days), and overall symptom severity. 3, 4
Side effects to counsel patients about: 1, 4
- Bad taste reactions occur in 60-80% of users 4
- Nausea affects 20-30% 4, 5
- Mouth/tongue/throat discomfort in approximately 37% 5
- Overall adverse effects in 88-90% of users 4, 5
The number needed to treat is favorable, but patients must weigh the high likelihood of taste disturbances and nausea against 3-4 days of symptom reduction. 2, 4
Common Pitfalls to Avoid
Underdosing is the most common mistake. Many over-the-counter zinc products contain insufficient elemental zinc per lozenge or recommend inadequate daily totals. 2 Doses below 75 mg/day have not shown consistent benefit. 2
Starting too late eliminates effectiveness. The 24-hour window from symptom onset is critical—zinc does not work if started after this period. 1, 2
Stopping too early reduces benefit. Patients must continue zinc throughout the entire cold duration, not just for 1-2 days. 1
Confusing prophylaxis with treatment. Currently, no firm recommendation can be made for prophylactic zinc supplementation due to insufficient data. 1 Zinc is for active treatment only, not prevention.
Special Populations
Children and adolescents: One randomized controlled trial in 249 school-aged children (grades 1-12) found no significant benefit from zinc gluconate glycine lozenges, though adverse effects were common. 5 However, a retrospective chart review showed benefit in school-aged subjects. 6 The evidence is mixed in pediatric populations.
Patients with diabetes: Sugar-free zinc gluconate glycine lozenges can be administered safely without deleterious effects on glycemic control. 7
Clinical Context
While zinc is effective, the American College of Physicians and European guidelines emphasize that the common cold is self-limited and symptomatic therapy is the primary management strategy. 1 Other proven symptomatic treatments include: 1
- Combination antihistamine-analgesic-decongestant products (1 in 4 patients achieve significant relief) 1
- Ipratropium bromide for rhinorrhea 1
- NSAIDs or acetaminophen for pain/fever 1
- Short-term decongestants for nasal congestion 1
Antibiotics should never be prescribed for the common cold, as they are ineffective and increase adverse effects. 1