Most adults experience an average of 2-3 colds yearly. Cold symptoms can be uncomfortable and may include a stuffy nose, sore throat, headache, mild body aches, sneezing, and coughing. While there is no cure for the common cold, evidence suggests that zinc may help reduce the severity and duration of colds.
Zinc is an essential trace mineral the body needs for immune function. It plays a key role in healing wounds and fighting bacteria and viruses. It also helps your body build proteins, produce DNA, and maintain good vision and a sense of taste. Adequate zinc levels are especially important during periods of growth, including infancy, childhood, adolescence, and pregnancy.
Research suggests that zinc may shorten a common cold by about two days and reduce the severity of symptoms. While experts don’t know precisely how zinc protects against colds, evidence suggests it may help in the following ways:
- Reduces viral replication: Zinc blocks rhinoviruses (the leading cause of colds) and other cold viruses from binding to cells in the respiratory tract (e.g., nose, throat) and multiplying. This may reduce symptom severity.
- Boosts immune function: Zinc regulates immune cell activity, helping to 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.
- May reduce respiratory tract inflammation: Zinc has anti-inflammatory properties that may help relieve symptoms like sore throat and nasal congestion (stuffy nose).
- Supports mucosal defense: The mucosal barrier that lines the inside of the respiratory tract helps trap bacteria and viruses, blocking them from entering the body. Research suggests that taking zinc daily may lower the risk of a cold by 5% by strengthening this barrier, making it harder for viruses to infect cells.
Study highlight: One review found that people with colds who took zinc saw improved symptoms by day three—right around the time symptoms usually peak.
Zinc is most effective at fighting colds if taken within 24 hours of symptoms developing. Supplements are available in several forms, including:
- Lozenges
- Nasal sprays
- Syrups
- Pills
Note: Lozenges (dissolving tablets) are the most common form of zinc for colds. They dissolve slowly, 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 (mg) of zinc daily in smaller doses throughout the day may help shorten the duration of a cold. Over-the-counter zinc lozenges often come in doses of 5-13.3 milligrams per tablet. Be cautious not to exceed 100 milligrams daily. There is no evidence that taking higher amounts improves its effectiveness.
What Foods Are the Best Sources of Zinc?
The body can’t produce or store zinc, so eating foods high in zinc is important for preventing zinc deficiency. These 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
Taking high amounts of zinc can cause side effects such as:
- Nausea
- Upset stomach
- Dizziness
- Headaches
- Vomiting
- Loss of appetite
Other complications: Taking high doses for prolonged periods can lead to more serious issues, such as copper deficiency or iron-deficiency anemia (low red blood cells or hemoglobin). Zinc nasal sprays and gels may cause loss of smell.
Tip: Taking some supplements on an empty stomach may increase your risk of nausea. Consider taking zinc after eating.
High doses of zinc (more than 40 milligrams daily) may not be safe for pregnant or breastfeeding people.
Zinc can also interact with certain drugs. 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 can help your body fight the cold virus.
- A cool mist humidifier can help break up mucus and relieve nasal congestion, making breathing easier.
- Warm water or herbal tea sweetened with honey can soothe a sore throat and ease coughs.
- Vitamin C is known for its immune-boosting properties. Taking 1,000-2,000 milligrams daily during a cold may help shorten symptom duration.
- 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 like Advil (ibuprofen) or Tylenol (acetaminophen) can help relieve headaches, body aches, and fever.
