From the Guidelines
Zinc supplementation can reduce the duration of the common cold when taken within 24 hours of symptom onset, with lozenges or syrup containing zinc acetate or zinc gluconate at doses of >=75 mg/day being effective. According to the most recent and highest quality study 1, zinc administered as zinc acetate or zinc gluconate lozenges at a dose of >=75 mg/day and taken within 24 hours of onset of symptoms significantly reduces the duration of common cold.
Key Points to Consider
- The optimal dosage is >=75 mg/day, with common formulations including Cold-Eeze or Zicam lozenges 1.
- Zinc works by inhibiting rhinovirus replication and may reduce inflammation in the nasal passages.
- Side effects can include nausea, bad taste, and mouth irritation, and patients should be aware of these potential adverse effects when using zinc lozenges 1.
- It is essential to weigh the potential benefits of zinc supplementation against the risk of adverse effects, particularly in patients with certain medical conditions or taking specific medications 1.
- Patients should also be advised to separate dosing of zinc and other medications, such as antibiotics and penicillamine, by at least 2 hours to minimize potential interactions.
Administration and Precautions
- Allow lozenges to dissolve slowly in the mouth rather than chewing them.
- Avoid zinc nasal sprays, which have been linked to permanent loss of smell.
- Be aware that zinc can interfere with certain medications, including antibiotics and penicillamine, so separate dosing by at least 2 hours if taking these medications. By considering these key points and taking the necessary precautions, patients can effectively use zinc supplementation to reduce the duration of the common cold.
From the FDA Drug Label
Uses reduce the duration of nasal congestion and shorten the length of the common cold Zinc supplementation reduces the duration of the common cold (upper respiratory tract infection) 2.
- The duration of nasal congestion is also reduced.
- Key benefit: Shortens the length of the common cold.
From the Research
Zinc Supplementation and Common Cold Duration
- The effect of zinc supplementation on the duration of the common cold has been investigated in several studies 3, 4, 5, 6, 7.
- A randomized, double-blind, placebo-controlled study found that zinc gluconate lozenges significantly reduced the duration of symptoms of the common cold, with a median duration of 4.4 days in the zinc group compared to 7.6 days in the placebo group 3.
- A systematic review of randomized controlled trials found that zinc supplementation was associated with a significant reduction in the duration of common cold symptoms, with a standardized mean difference of -0.97 4.
- Another systematic review found that zinc supplementation reduced the duration of the common cold by 2.25 days when provided singly 5.
- A double-blind, placebo-controlled trial found that zinc nasal gel shortened the duration of common cold symptoms by 6.7 days when taken within 24 hours of onset 6.
- A Cochrane review of 34 studies found that zinc supplementation may reduce the duration of ongoing colds, but the evidence was of low certainty due to the high risk of bias and heterogeneity between studies 7.
Adverse Events
- The studies found that zinc supplementation was associated with an increased risk of adverse events, including bad taste, nausea, and unpleasant taste 3, 4, 7.
- The Cochrane review found that there was probably an increase in the risk of non-serious adverse events when zinc was used for cold treatment, but the evidence was of moderate certainty 7.