Zinc for Colds: Does It Work + How Much to Take

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Zinc may not act as a cure-all when you’re sick, but studies show it can shorten the duration of your cold and the severity of symptoms. It’s even more effective when you act quickly. Those same studies report shorter colds with the use of zinc at the first sign of illness.

What Does Research Say About Zinc for Colds?

Studies show the sneezing, runny nose, and sore throat symptoms commonly experienced with colds are much less severe with zinc supplements as part of your home remedies.

Zinc may also get you get back on your feet faster. A meta-analysis found that zinc taken within 24 hours of the onset of a cold reduced the duration of symptoms by about 33%. Another found that zinc supplementation may shorten colds by about 2.25 days over a placebo. 

Self-reporting can make these kinds of studies more limiting than others, but the research is clear: A zinc supplement can get you feeling better faster, especially at the onset of symptoms.

What’s less clear is how zinc works. It seems to inhibit the replication of rhinovirus, the main cause of colds. This means it may prevent the virus from binding to cells and preventing the worst symptoms of the common cold.

It may also help calm your trigeminal nerve. This is the part of the nervous system responsible for function in your face, including any pain and temperature changes. 

When you have a cold, this nerve triggers what you feel when you sneeze. The thinking here is that anything that numbs the nerve can reduce the severity of symptoms related to sneezing and a runny, stuffy nose.

Finally, zinc may have a positive effect on immune cells. Studies show people with a zinc deficiency are more susceptible to infectious diseases, fatigue, mental health concerns, and inflammation. Women with low zinc levels may have a higher risk of urinary tract infections.

This doesn’t mean zinc prevents illness or cures colds, but getting enough zinc does support a healthy immune system.

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Recommended Dosage

Your body doesn’t need much zinc to properly function, but you do need this trace mineral for a healthy immune system and cell growth. The amount of zinc you need daily depends on your age, overall health, and whether you’re using it as a cold remedy.

The Office of Dietary Supplements from the National Institutes of Health (NIH) recommends this amount of zinc in order to avoid deficiency:

  • Adult men: 11 mg/day
  • Adult women: 8 mg/day
  • When pregnant or breastfeeding: 11-12 mg/day

The recommended upper limit for healthy adults is 40 mg of zinc per day. That includes zinc in all of its forms, including diet-based sources, zinc supplements, and multivitamins that contain zinc. 

Most adults need around 15-30mg of supplemental zinc in order to have optimal levels for body function. At PrimeHealth, we check zinc levels in many of our patients in order to properly direct the amount of zinc they should be supplementing with for optimal function. 

If you’re using zinc to shorten the duration of cold symptoms, studies show 80-92 mg at the onset of illness is a good benchmark. It’s important to return to recommended limits once you’re feeling better to prevent side effects from too much zinc.

Zinc Supplements and How to Choose

Zinc supplement formulations can include a few different types of zinc. Zinc gluconate, zinc acetate, zinc glycinate, and zinc citrate are the most widely available. 

Choosing the right supplement for you may require some trial and error. You may tolerate one over another. Studies show zinc glycinate offers the best bioavailability, meaning your body can likely absorb it better than other forms of zinc. 

It’s more important to read labels and look for products with minimal additives that meet your needs. Those with a zinc deficiency may need a different supplement than those seeking to beat a cold. 

If you have other nutritional needs, you may benefit from supplements that include nutrients or antioxidants like vitamin C, n-acetylcysteine (NAC), and magnesium.

There are also different delivery methods of zinc. You can find it as:

  • Capsules/tablets
  • Lozenges
  • Liquid drops
  • Syrup
  • Nose swabs

Zinc lozenges are the most researched form of zinc for colds, thanks to their astringent effect on your throat. Start zinc within the first 24 hours of a cold for the best results. Avoid taking more than directed, and don’t go beyond the upper limits once you feel better.

Exercise extra caution with zinc nasal sprays, which have been linked to a reduced sense of smell in some. Some popular brands have removed zinc from their sprays because of incidences of a temporary or even permanent loss of smell.

Talk to your healthcare provider before starting any new supplement regimen, especially if you’re worried about interactions with medications or any preexisting health conditions.

Food Sources of Zinc

Most well-balanced diets include sources of zinc. There is evidence to suggest that zinc levels in soil may be decreasing in some regions due to factors such as soil erosion, depletion from intensive agricultural practices, and changes in land use. A decrease in minerals like zinc in our soil is also leading to decreasing levels in our food.

Oysters and mussels are at the top of the list of zinc food sources, but red meat, chicken, eggs, cheese, and milk all contain healthy amounts of zinc. 

If you don’t eat meat, seafood, or dairy, legumes like chickpeas, beans, nuts, whole grains, and potatoes are good alternatives.

A true zinc deficiency in the United States is rare but can happen with a poor diet. The elderly and anyone with malabsorption syndrome or other digestive issues are at risk. In those cases, supplementation may help you get your zinc levels back on track until those other factors are addressed. 

A boost in zinc outside of food sources is also a good idea when you’re feeling the first signs of a cold.

Potential Side Effects and Considerations

The efficacy of zinc does not continue increasing past a certain dose threshold, meaning that you won’t necessarily get extra benefits by taking way more zinc than you need. Stay within recommended limits for maximum benefits when feeling sick.

Excessive zinc can cause adverse effects like nausea, diarrhea, and a metallic or bad taste in the mouth. Long-term zinc use can affect how your body absorbs minerals like iron and copper.

If you’re worried that you have a true zinc deficiency, talk to your healthcare provider. We can perform blood tests for zinc to spot a deficiency. They can provide you with dosage recommendations for a zinc supplement to see if any reported symptoms improve.

Talk to your doctor if you’re taking antibiotics, too, as zinc can interfere with certain medications.


Does Zicam actually shorten colds?

Zicam can shorten colds, but the same is true of other zinc-based products under different brand names. Note that Zicam nasal sprays no longer include zinc due to concerns over loss of smell.

How do you shorten a cold fast?

You can shorten a cold fast by supplementing with the recommended amount of zinc, getting plenty of rest, and staying hydrated. Supplementing with vitamin C when you’re sick can also boost your immune system and help your body absorb the extra zinc. 

How does zinc help your immune system?

Zinc helps your immune system by supporting the development and function of immune cells. You don’t need high doses of it for proper immune function, but a deficiency can make you more susceptible to infections.

What form of zinc is best for colds?

You can take zinc in any oral form for colds. There have been more studies done on zinc lozenges, and they can help to soothe the throat, but they’re not necessarily more effective than another type of oral zinc. You just need to take zinc that absorbs well enough to raise your serum levels of zinc.

Zinc gluconate, zinc acetate, zinc glycinate, and zinc citrate are common types of zinc found in supplements that boost zinc in the body when you’re sick. Again, all of these forms are about the same level of effectiveness.

How much zinc should I take at the first sign of a cold?

You should take anywhere from 75-100 mg of zinc throughout the day at the first sign of a cold. (Clinical trials show 80-92 mg is ideal.)

When to See a Doctor

Most colds go away within 7-10 days with home remedies that include zinc supplementation. If you’re still sick after 10 days, or if your symptoms are worsening, you develop a high fever or chest pain, or have difficulty breathing, call your healthcare provider.

Looking for high-quality supplements to support optimal wellness? Check out PrimeHealth’s marketplace! Each supplement is medical grade, third-party tested, and hand-picked from our expert team of medical providers based on science and real-life patient experience.


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