Quick answer
Research on zinc lozenges is more encouraging than for many cold products. A 2017 meta-analysis of seven placebo-controlled trials found that colds were about a third shorter on average in people who used zinc lozenges providing more than 75 mg of zinc a day. Starting them early and using them only for a short time is what the studies looked at.
Key takeaways
Zinc lozenges have more encouraging research behind them than many other cold remedies.
In the studies, people started the lozenges soon after noticing symptoms and used them only for a short time.
A bad taste or mild nausea is common, and long-term high intake of zinc can lower copper levels.
Zinc lozenges are a common item in many cold-season cabinets. Here is what the research on them actually measured and what to keep in mind before you use them.
What did the research find?
In a 2017 meta-analysis, Dr. Harri Hemilä pooled seven placebo-controlled trials in which participants used zinc lozenges providing more than 75 mg of zinc a day. On average, colds were 33 percent shorter in the zinc groups. Zinc acetate and zinc gluconate lozenges performed similarly, and doses above 100 mg a day did not show added benefit.
How were zinc lozenges used in the studies?
In these trials, people usually started the lozenges within a day of noticing cold symptoms and let them dissolve slowly in the mouth throughout the day. They used them only for the length of the cold, not as a long-term daily supplement.
Are there downsides to zinc lozenges?
Some people notice a bad taste or mild nausea. Long-term high doses of zinc can lower copper levels, which is why these studies used them only for a short time. Zinc nasal sprays are a different product and have been linked to loss of smell, so they are not the same as lozenges. Check with your provider if you are pregnant, take antibiotics, or have a health condition.
Where can I find a quality zinc lozenge?
You can find practitioner-grade options in my Fullscript store, which offers professional brands with strong quality standards.
Looking for a quality option from a professional brand? My Fullscript store has you covered.
Questions to bring to your clinician
These questions can help you get the most out of your next visit.
Would zinc lozenges be a reasonable option for me during cold season?
Could any of my current medications or supplements interact with the options discussed here?
Would any lab testing add useful information in my situation, or is it reasonable to start with daily habits?
Which one or two changes would be most worthwhile for me to focus on first?
Practitioner-grade options in my Fullscript catalog: if you and your clinician decide a supplement makes sense, my supplement guide by health goal links to the practitioner-grade products I trust.
Frequently asked questions
Do zinc lozenges shorten colds?
A 2017 meta-analysis of seven trials found that colds were on average 33 percent shorter with zinc lozenges providing more than 75 mg of zinc a day.
Is zinc acetate or zinc gluconate better?
The same analysis found no significant difference between zinc acetate and zinc gluconate lozenges.
How long should I use zinc lozenges?
The studies used them only during a cold, starting early. Long-term high doses can lower copper levels.
Sources
- Hemilä H. Zinc lozenges and the common cold: a meta-analysis comparing zinc acetate and zinc gluconate, and the role of zinc dosage. JRSM Open. 2017. https://pubmed.ncbi.nlm.nih.gov/28515951/
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This page shares general educational information and is not medical advice. These statements have not been evaluated by the Food and Drug Administration. Talk with your healthcare provider before starting a supplement, especially if you take medications, are pregnant or nursing, or have a health condition.
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