Zinc for Colds: How Does It Work?

The common cold is, well, common. Most adults experience an average of 2-3 colds yearly. When experiencing uncomfortable cold symptoms like stuffy nose, sore throat, headache, mild body aches, sneezing, and coughing, you may turn to over-the-counter (OTC) medications and natural remedies for much-needed relief. 

While there is no cure for the common cold, evidence suggests that zinc—an essential mineral the body needs for immune function—may help reduce the severity and duration of colds.

Zinc is an essential trace mineral your body needs to help the immune system fight bacteria and viruses, heal wounds, and maintain good vision and a sense of taste. It also helps your body produce DNA (genetic material in cells) and build proteins. Adequate zinc levels are essential during periods of growth, such as infancy, childhood, adolescence, and pregnancy. 

The body can’t produce or store zinc, so eating foods containing zinc is important for preventing zinc deficiency. Zinc-rich foods include: 

• Shellfish, such as oysters and crabs 
• Meats, including beef, pork, and turkey 
• Beans and nuts, such as pumpkin seeds, sesame seeds, and kidney beans
• Whole grains, like oats and rice
• Eggs
• Fortified breakfast cereals
• Dairy products, including milk and cheese

Research suggests that zinc may shorten the duration of the common cold by about two days and reduce the severity of symptoms. How zinc protects against colds is not fully understood, though evidence suggests it may help in the following ways: 

• Reduces viral replication: Zinc inhibits the replication of viruses that cause the common cold, such as rhinoviruses (the most common cause). It blocks the virus’s ability to bind to cells in the respiratory tract and multiply, possibly helping reduce symptom severity. In one study, people with colds who took zinc experienced improvements in symptoms by day three—right around the time symptoms usually peak.
• Boosts immune function: Zinc helps keep your immune system strong. It regulates immune cell activity, helping fight off bacteria and viruses. This may be why taking zinc at the start of a cold can help it resolve up to three times faster.
• Reduces inflammation: Zinc has anti-inflammatory properties that may help reduce respiratory tract inflammation, helping relieve uncomfortable symptoms like sore throat and nasal congestion (stuffy nose). 
• Supports mucosal defense: The mucosal barrier lines the inside of the respiratory tract (e.g., nose, throat) and traps and blocks bacteria and viruses from entering the body. Research suggests that daily zinc supplementation may lower the risk of developing a cold by 5% by strengthening the mucosal barrier, making it harder for cold viruses to infect cells. 

Zinc is most effective at fighting colds if taken within 24 hours of cold symptoms developing. It is available in several forms, including lozenges, nasal sprays, syrups, and pills.

Lozenges are the most common form of zinc for colds; they dissolve slowly in the mouth, allowing zinc to coat the mouth, nasal passages, and throat. This may make them more efficient than pills at stopping cold viruses from replicating.

Recommended Dosage

For adults, taking 75–100 milligrams of zinc per day, divided into smaller doses throughout the day, may help shorten the duration of a cold. Zinc lozenges available over the counter come in doses ranging from 5-13.3 milligrams per lozenge.

Sucking on a zinc lozenge every few hours until you reach 75-100 milligrams may help fight a cold. Be cautious not to exceed 100 milligrams daily, there is no evidence that taking higher amounts improves its effectiveness. 

While zinc may help manage cold symptoms and help you feel better sooner, there are some potential side effects and risks to consider before adding it to your cold-fighting regimen. 

Taking high amounts of zinc can cause side effects such as: 

• Nausea
• Upset stomach
• Dizziness
• Headaches
• Vomiting
• Loss of appetite 

Taking high doses of zinc for prolonged periods can lead to more serious issues, such as copper deficiency or iron-deficiency anemia (low red blood cells or hemoglobin). Some evidence suggests that zinc nasal sprays and gels can cause loss of smell.

High doses of zinc (more than 40 milligrams daily) may not be safe for pregnant or breastfeeding people. Zinc can interact with certain medications, so talk to a healthcare provider before using zinc if you take any of the following medications:

• Antibiotics 
• Penicillamine (rheumatoid arthritis treatment) 
• Diuretics (water pills)

A variety of other remedies may help soothe cold symptoms and support quicker recovery:

• Rest and hydration: Getting enough rest and drinking fluids can help your body fight the cold virus.
• Cool mist humidifier: A cool mist humidifier can help break up mucus and relieve nasal congestion, making breathing easier. 
• Warm beverages with honey: Warm herbal tea sweetened with honey can soothe a sore throat and ease coughs. 
• Vitamin C: Vitamin C is known for its immune-boosting properties. Taking 1,000-2,000 milligrams daily during a cold may help shorten the duration of symptoms.
• Hot shower or steam bowl: Taking a hot shower or inhaling steam from a bowl of hot water can help relieve nasal congestion and open up blocked sinuses. 
• Over-the-counter (OTC) pain relievers: OTC pain relievers like Advil (ibuprofen) or Tylenol (acetaminophen) can help relieve headaches, body aches, and fever. 

Zinc is an essential mineral that helps support several body processes, including a strong immune system. When taken at the first signs of a cold, zinc lozenges or supplements may help reduce the duration and severity of cold symptoms.

While zinc may be effective, other remedies (e.g., rest, drinking plenty of fluids, OTC pain relievers) can help relieve symptoms and promote a speedy recovery. As with all dietary supplements, it’s a good idea to talk to a healthcare provider before taking zinc to prevent or treat a cold.