Does Zinc Help With Colds?

Most people will do anything to get over a cold more quickly. Since there’s no treatment or cure for a cold, your options are usually limited to taking over-the-counter (OTC) medications and supplements to help find some relief. For some people, zinc supplements are a part of their cold treatment routine. 

Studies have shown that zinc can reduce your symptoms — and help you feel better faster. But it helps to know a few basics about zinc before you give it a try. 

Can zinc help a cold?

Researchers have looked into whether zinc can help fight off a cold. And they’ve seen some positive results. In some studies, zinc has been shown to:

• Prevent colds

• Shorten colds

• Ease cold symptoms

This hasn’t been true across the board though. Other studies haven’t found zinc to be that helpful. This may be related to the form and dose of zinc included in the study.

But while the research is mixed, zinc is unlikely to hurt when you’re feeling sick. It’s best to take zinc as soon as you have the first sign of a cold. It may not be as helpful if you’ve already had symptoms for several days.

How much zinc should you take for a cold?

The recommended daily allowance of zinc for adults is 8 mg to 11 mg per day. Most people who’re eating a regular, balanced diet are likely getting enough zinc. But if you’re feeling sick, you can give yourself an extra boost. The best dose of zinc for colds is still unclear though. 

Some researchers think an extra 15 mg of zinc a day is enough to help with a cold. Others think the optimal dose of zinc for a cold is around 80 mg daily. But most agree that more than 100 mg a day provides no added benefit. 

To be safe, aim for 15 mg to 30 mg daily, in addition to what you get from your diet. This way, you know that you won’t go above the upper recommended limit of zinc per day (between both food intake and supplements). 

When trying to figure out how much zinc is in a particular supplement, pay attention to the amount of “elemental zinc” listed on the label. Different supplements have different types and amounts of zinc in them. But the listed amount of elemental zinc will tell you how much zinc you’re getting in each dose.

EXPERT PICKS: WHAT TO READ NEXT

• What’s the best thing to eat when you have a cold? Many helpful nutrients can come from your diet rather than a supplement. Here are some of the best foods when you have a cold.

• Vitamin C and colds: Many people swear by high doses of vitamin C when they start to get sick. But does it help?

• Ways to get rid of a cold: People share their favorite home remedies to help get over a cold as fast as possible.

What happens if you take too much zinc? 

If you take too much zinc, it can lead to unwanted side effects. These include:

• Nausea

• Vomiting

• Diarrhea

• Stomach pain

• Loss of appetite

• Headaches

• Dizziness

And this isn’t all. When you take too much zinc, it interferes with the absorption of copper. This is another important mineral for your body. Low levels of copper can lower your red and white blood cell counts. You need both of these to keep your immune system — and the rest of your body — running strong.

How does zinc help your immune system?

Zinc is a nutrient that is found throughout many cells in the body. It plays a role in:

• Growth and development, especially during pregnancy, infancy, childhood, and puberty

• Wound healing

• Your sense of smell and taste

• Immune system function

It isn’t fully understood how zinc helps the immune system. Scientists believe that zinc may help prevent certain viruses in the body from replicating. When viruses can’t replicate, the body is able to fight them off and eliminate them faster.

What kind of zinc is best for a cold?

There are many different kinds of zinc available, including:

• Lozenges: This is the most common form for colds.

• Pills: Zinc supplements come in both capsule and tablet form. 

• Liquids and powders: These forms can be mixed into water or juice.

• Nasal sprays: There’s some concern that this type may lead to permanent loss of smell.

When it comes to treating colds, lozenges have been studied the most. It isn’t clear if other forms of zinc have the same effect on colds. It can be tempting to just keep opening a new lozenge. But it’s important to keep track of how much zinc you’re taking so that you don’t overdo it.

Who shouldn’t take zinc for a cold?

You should avoid taking zinc supplements if you take certain medications. These include:

• Quinolone and tetracycline antibiotics: Zinc may decrease the amount of antibiotic that your body absorbs, causing it to be less effective.

• Amiloride (Midamor): This is a diuretic that can cause increased levels of zinc in the body.

Other medications can increase how much zinc you lose in your urine. If you’re taking any of the medications listed below, talk to a healthcare professional before taking a zinc supplement:

• ACE inhibitors and thiazide diuretics: common medications for high blood pressure

• Cisplatin: a chemotherapy medication

• Deferoxamine: a medication used to remove excess iron from the blood

• Penicillamine: used to treat Wilson’s disease (a condition that leads to too much copper in the body)

Even if you don’t take any of these medications, it’s always a good idea to talk to your primary care provider before starting any supplement. They can help determine if it's safe for you.

Frequently asked questions

Why trust our experts?

Written by:

Cherilyn Davis, MD

Cherilyn Davis, MD, is a board-certified pediatrician in New York City. She has held local and national roles at the American Medical Women’s Association including board member of the physician division and physician chair of social media.

Edited by:

Katie E. Golden, MD

Katie E. Golden, MD, is a board-certified emergency medicine physician and a medical editor at GoodRx.

Our editorial standards

Meet our experts