Every cold and flu season, zinc lozenges fly off pharmacy shelves. Some people swear they knock a cold out fast. Others take zinc every day all winter hoping never to catch one at all. So which is it?
The honest answer is somewhere in the middle. Zinc may help a cold go away a little sooner if you start it early, but it doesn’t seem to keep colds away. And more zinc isn’t better: taking too much for too long can cause real problems. Here’s what the research says, how to get zinc from food, and who might actually need a supplement.
What Does Zinc Do?
Zinc is a mineral found in cells throughout your body. It helps your immune system fight off bacteria and viruses, and your body uses it to make proteins and DNA. It also helps wounds heal, supports normal growth in pregnancy and childhood, and plays a part in your sense of taste.
Zinc is one of several minerals that work quietly in the background. For a broader look at how they fit together, see our article on mineral nutrition and the big jobs small nutrients do.
How Much Do You Need?
Not a lot. The recommended amounts for adults are 11 milligrams (mg) a day for men and 8 mg for women. Needs rise to 11 mg during pregnancy and 12 mg while breastfeeding. Children need less, depending on age.
Most people in the U.S. get enough zinc from food. Survey data summarized by the NIH show average food intakes of about 13 mg a day for men and 9.2 mg for women. That said, the same data suggest about 15% of U.S. adults fall below the average requirement, and older adults are more likely to have marginal intakes.
Food First: Where Zinc Comes From
Zinc shows up in a lot of everyday foods. Here are some easy sources, with amounts from the NIH Office of Dietary Supplements:
- Oysters, 3 ounces cooked (Pacific): about 28 mg, more than any other food
- Beef sirloin, 3 ounces roasted: about 3.8 mg
- Blue crab, 3 ounces cooked: about 3.2 mg
- Fortified breakfast cereal, 1 serving: about 2.8 mg (varies, so check the label)
- Oatmeal, 1 cup cooked: about 2.3 mg
- Pumpkin seeds, 1 ounce roasted: about 2.2 mg
- Pork chop, 3 ounces: about 1.9 mg
- Cheddar cheese, 1.5 ounces: about 1.5 mg
- Lentils, ½ cup boiled: about 1.3 mg
- Plain Greek yogurt, 6 ounces: about 1.0 mg
Fruits and vegetables contain very little zinc, so a produce-heavy plate still needs some of the foods above.
A Note for Plant-Based Eaters
Beans, nuts and whole grains contain zinc, but they also contain phytates, natural compounds that bind zinc and reduce how much you absorb. That’s why vegetarians and vegans tend to have lower zinc intakes and levels. A few kitchen habits can help: soaking beans, grains and seeds for several hours before cooking, using canned beans, and eating fermented foods like sourdough bread. Some vegetarians and vegans may also benefit from a supplement. Our guide to vitamin absorption factors covers more of what affects how well your body takes in nutrients.
Zinc and Colds: What the Research Shows
This is the big one, so let’s be clear about what’s known and what isn’t.
Treating a cold. A 2024 Cochrane review of 34 trials found that zinc, mostly as lozenges, may shorten a cold by about two days when people take it after symptoms start. It’s unclear whether it makes symptoms any less severe. The reviewers rated their confidence in the evidence as low to very low, partly because the studies used very different products, doses and schedules.
Preventing a cold. The same review found that taking zinc regularly may make little to no difference in whether you catch a cold. So a daily zinc pill all winter is unlikely to keep you from getting sick.
Timing seems to matter. In studies where zinc helped, people usually started lozenges or syrup right at the start of a cold. Lozenges dissolve slowly in the mouth and throat, which researchers think may be part of how they work. Scientists still don’t agree on the best dose, form or length of use.
Side effects are common. The Cochrane reviewers found people taking zinc for a cold were more likely to report side effects, mostly a bad or odd taste and an upset stomach.
If you’re building a cold-season routine, our articles on vitamin C and immune support and the best vitamins for immune resilience look at the other nutrients people often reach for this time of year.
Skip Zinc in the Nose
Zinc lozenges are one thing. Zinc nasal gels and swabs are another. In 2009 the FDA told consumers to stop using three zinc nasal cold products after more than 130 reports of lost sense of smell, which may be long-lasting or permanent. Given that warning, it makes sense to skip zinc products that go in your nose and stick with food, or with lozenges if you choose to try them.
Who May Need More Attention
The NIH lists several groups who may have trouble getting enough zinc:
- People with digestive conditions such as Crohn’s disease or ulcerative colitis, or who have had weight-loss or other gastrointestinal surgery
- Vegetarians and vegans, because of lower intake and lower absorption
- People who are pregnant or breastfeeding, because needs go up
- Breastfed babies older than 6 months, who need zinc-rich foods like pureed meats
- Children with sickle cell disease
- People with alcohol use disorder, because alcohol lowers absorption and raises losses
Signs of low zinc can include loss of taste or smell, slow wound healing, frequent infections and hair loss. But many of these have other causes too, so it’s worth talking with your doctor rather than guessing. Blood tests for zinc also have limits, so doctors usually look at your diet, health conditions and symptoms together.
A Special Case: Macular Degeneration
Zinc has one well-studied, specific use. In the large AREDS trials, older adults at high risk of advanced age-related macular degeneration (AMD), an eye disease that causes vision loss, who took a daily supplement with zinc, copper and certain antioxidants had slower progression to the advanced stage. These formulas contain far more zinc than the daily upper limit, so they’re meant for people with AMD under an eye doctor’s care, not as a general supplement.
Can You Get Too Much Zinc?
Yes, and this is where zinc differs from some other nutrients. The upper limit for adults is 40 mg a day from all sources, including food, supplements, lozenges and multivitamins combined. That limit doesn’t apply when a doctor prescribes zinc for a medical reason.
- Short-term: too much zinc can cause nausea, vomiting, stomach upset, headaches, dizziness and loss of appetite.
- Over weeks: doses of 50 mg or more can block copper absorption, weaken immune function and lower HDL (“good”) cholesterol. Low copper can eventually cause anemia and nerve problems.
- Hidden sources add up: cold lozenges, multivitamins and some denture creams all contain zinc. Heavy, long-term overuse of zinc-containing denture cream has been linked to copper deficiency and nerve damage.
Here’s the catch with lozenges: many cold studies used daily totals well above 40 mg. That’s one reason to use them only for a few days at the first sign of a cold, follow the label, and not stack them on top of a high-dose zinc supplement.
Medication Interactions
Zinc can interact with some common medicines, according to the NIH Office of Dietary Supplements:
- Certain antibiotics. Quinolones (such as ciprofloxacin) and tetracyclines can bind with zinc, so both are absorbed less. Take the antibiotic at least 2 hours before, or 4 to 6 hours after, zinc.
- Penicillamine. Zinc can lower absorption of this drug used for rheumatoid arthritis and Wilson disease. Take them at least 1 hour apart.
- Thiazide diuretics. Water pills such as hydrochlorothiazide and chlorthalidone increase zinc lost in urine, which may lower zinc levels over time.
Also, iron supplements of 25 mg or more taken at the same time can reduce zinc absorption, and very high zinc doses can interfere with magnesium. If you take several minerals, ask your pharmacist about spacing them out. Our magnesium supplement guide has more on that mineral.
If You Do Take a Supplement
- Check your multivitamin first. Almost all multivitamin/mineral products already contain zinc, so you may not need a separate pill.
- Form matters less than you’d think. Zinc gluconate, sulfate, acetate and citrate are common, and the NIH says it’s not clear one form is better than the others.
- Read the label for elemental zinc. The Supplement Facts panel lists the amount of actual zinc, not the weight of the whole compound. Add up every product you take.
- Take it with food if it upsets your stomach. Nausea is one of the most common complaints.
Our guide on how to choose a multivitamin walks through reading a label, and how to improve mineral intake has more food-first ideas.
Simple Steps to Take This Week
- Look at a typical week of meals. Do you regularly eat seafood, meat, dairy, eggs, beans, seeds or whole grains?
- If you eat plant-based, try soaking beans and grains, and add pumpkin seeds or fortified cereal.
- Add up the zinc in every supplement you take, including your multivitamin, and keep the total under 40 mg unless your doctor says otherwise.
- If you want to try lozenges, keep them for the first day or two of a cold, follow the label, and stop after a few days.
- Toss any zinc nasal sprays, gels or swabs.
- If you take antibiotics, penicillamine or a water pill, ask your pharmacist how to time zinc.
If You Shop With Us
Disclosure: Info Health News is run by an independent Youngevity distributor, and we may earn a commission when you purchase through our links. Product information below comes from the company and is not independent evidence of any health benefit.
If you’d rather get zinc as part of a broader multivitamin than as a stand-alone pill, Youngevity’s ingredient list for Beyond Tangy Tangerine® 2.5 includes zinc along with copper, selenium and other vitamins and minerals. We cover what’s in it in our Beyond Tangy Tangerine 2.5 overview. Check the Supplement Facts label for the exact amount and count it toward your daily zinc total. A multivitamin isn’t a cold treatment. To browse or order, visit our Youngevity products page, which links to the online store.
The Bottom Line
Most people get enough zinc from a varied diet, and a daily zinc pill probably won’t stop you from catching colds. Zinc lozenges started at the first sign of a cold may shorten it by a day or two, though the evidence isn’t strong and side effects like a bad taste and nausea are common. Keep your total under 40 mg a day unless your doctor advises more, skip zinc in the nose, and pay closer attention if you’re plant-based, pregnant, have a digestive condition, or take medicines that interact with zinc.
This article is for educational purposes only and isn’t medical advice. Talk with your doctor or pharmacist before starting a supplement, especially if you’re pregnant, take medication or have a health condition. See our medical disclaimer.