Preventing and treating the common cold: what’s the evidence?

Dr Lynda Ware looks at the Cochrane evidence behind 14 possible interventions for treating or preventing the common cold – is there anything that might help and what are the possible risks?

Originally published: 19 January 2017, republished 21 March 2022 with updated evidence.

Take-home points Vitamin supplements: Vitamin D supplements help prevent upper respiratory tract infections, especially in people who are deficient in vitamin D. Among the general population, vitamin C may have little or no effect on reducing the chance of getting a cold. Medicines: Antihistamine-analgesic-decongestant combinations, available over-the-counter, may help relieve symptoms. On their own, antihistamines probably have limited short‐term benefits, and multiple doses of nasal decongestant may only help a little with congestion. Paracetamol may help relieve some, but not all, symptoms. There is little evidence on steroids, but they may have little to no benefit. Antibiotics are associated with side effects and antibiotic resistance and there is no reliable evidence that they are helpful for colds Home and herbal remedies: Honey probably helps relieve cough in children older than 12 months. There is little evidence about steam inhalation, garlic or echinacea. Vaccines: there is very limited evidence about vaccines for preventing the common cold, but they may have little to no benefit

The common cold is characterized by a runny nose, sore throat, congestion, cough, feeling unwell, and sometimes mild fever. If you have symptoms like these, there is a chance it could be COVID instead. If you’re unsure, you can find out how to access COVID tests in the UK.

Common colds usually go away by themselves, with symptoms typically lasting one to two weeks. Nonetheless, colds can lead to significant time off work and school, as well as using up doctors’ appointments.

On average, adults may get 2-4 colds per year and young children as many as 6-8. Yet despite its prevalence, a cure for the common cold has eluded medical science and treatment is aimed at relieving symptoms. There is also no foolproof way of preventing it either.

In this blog, we look at the evidence behind interventions in four categories:

  • Vitamin supplements
  • Medicines
  • Home and herbal remedies
  • Vaccines

Vitamin supplements

Vitamin D

There is reliable evidence that vitamin D supplements help prevent upper respiratory tract infections, especially in those who have a deficiency.

This comes from the review vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data (February 2017). While vitamin D is best known for its effect on calcium metabolism and for keeping our bones healthy, it appears to have benefits in preventing the common cold as well.

The NHS advises that everyone should consider taking a daily supplement containing 10 micrograms of vitamin D during the autumn and winter.

Skiing
Only people doing extreme exercise, like skiers, seemed to benefit from vitamin C.

Vitamin C

Vitamin C supplementation may have little or no effect on reducing the chance of getting a cold in the general population, though it may be useful for people who do brief periods of extreme physical exercise.

There was great excitement in the 1970s when Linus Pauling, (a Nobel laureate twice over), concluded from placebo-controlled trials that vitamin C could prevent and alleviate the common cold. Further research followed and a Cochrane Review Vitamin C for preventing and treating the common cold (January 2013). Unfortunately, the review did not confirm Pauling’s findings.

Taking regular Vitamin C did not seem to reduce the incidence of colds in the general population, although there was a modest reduction in the duration and severity of symptoms. The only people who appeared to benefit were those who undertook short bursts of extreme exercise, such as marathon runners and skiers. In this group, the risk of getting a cold was halved.

Studies looking at taking high-dose vitamin C at the onset of cold symptoms suggest there may be little to no consistent effect on the duration and severity of symptoms. More research is needed to clarify these findings.

Find out more:

Medicines

Oral antihistamine / decongestant / analgesic combinations

These appear to have some benefit in relieving symptoms, but this must be weighed against side effects.

These combination preparations are widely available over-the-counter (OTC) in pharmacies and supermarkets. A Cochrane Review Oral antihistaminedecongestantanalgesic combinations for the common cold (January 2022) concluded that they have some general benefit in relieving symptoms and aiding recovery in adults and older children.

The most effective combination seems to be an antihistamine/decongestant combo but the benefits must be weighed against side effects such as drowsiness, dry mouth, sleep disturbance and dizziness.

Sinus problems
Nasal decongestants may help a little with nasal congestion – but it’s unclear how much.

Nasal decongestants used alone

Multiple doses of nasal decongestant may help a little with nasal congestion – but it is unclear how helpful this feels to the patient.

This is the conclusion of the Cochrane Review Nasal decongestants in monotherapy for the common cold (October 2016).

As with any medicine, it is important not to exceed the recommended doses.

Paracetamol

Paracetamol may relieve nasal obstruction and runny nose, but it does not appear to help other symptoms such as sneezing, sore throat, cough and feeling unwell.

This is what the authors of a Cochrane Review Acetaminophen (paracetamol) for the common cold in adults (July 2013) conclude. They also note the need for better research to clarify just how effective paracetamol really is in providing symptom relief.

Non-steroidal anti-inflammatory drugs (NSAIDs)

NSAIDs probably help pain associated with colds (such as headache) but not other cold symptoms.

This was the conclusion of the Cochrane Review Nonsteroidal antiinflammatory drugs for the common cold (September 2015). They are associated with side-effects such as irritation of the stomach lining.

Find out more: Is there randomized controlled trial evidence to support the use of non-steroidal anti-inflammatory drugs in people with the common cold? (Cochrane Clinical Answer).

Antihistamines

For adults, antihistamines probably have a limited short‐term (days one and two of treatment) beneficial effect on severity of overall cold symptoms, but not in the mid- to long term.

The Cochrane Review Antihistamines for the common cold (November 2015) found that the severity of cold symptoms probably improved on day 1 or day 2 in more people taking antihistamines than those taking placebo (a dummy tablet). This was no longer the case from day 3 onwards and there was an increased risk of side-effects such as sleepiness.

The review authors found no evidence on antihistamines for children with colds.

Find out more: What are the benefits and harms of antihistamines for people with the common cold? (Cochrane Clinical Answer).

Pill choice for common colds
Antibiotics aren’t helpful for colds and can cause side-effects.

Antibiotics

Antibiotics have not been shown to be helpful for the common cold and are associated with side effects and antibiotic resistance.

Common colds are caused by viruses, which are unaffected by antibiotics. The Cochrane Review Antibiotics for the common cold and acute purulent rhinitis (June 2013) looked at the use of antibiotics in the treatment of colds and purulent rhinitis (coloured mucus from the nose). Perhaps not surprisingly, antibiotics were not shown to be effective and were associated with side-effects.

Find out more: What are the benefits and harms of antibiotics for people with the common cold and/or acute purulent rhinitis? (Cochrane Clinical Answer).

Corticosteroids

There is little evidence about the effects of steroids on the common cold and, so far, it seems they may have little to no benefit.

These drugs act as powerful anti-inflammatory agents in other upper respiratory infections but the little evidence available to include in the Cochrane Review Corticosteroids for the common cold (October 2015) suggests that intranasal corticosteroids may have little to no effect on cold symptoms.

Steam inhalation
Inhaling steam may have little or no effect on symptoms of the common.

Home and herbal remedies

Steam inhalation

There is little evidence available and there may be no clear improvement or worsening of cold symptoms.

Inhaled steam has been used for decades, the thinking being that it helps drain away mucus more effectively and possibly destroys the cold virus.

The Cochrane Review Heated, humidified air for the common cold (August 2017) concluded that the little evidence available shows that there may be little to no benefit or harm of inhaling heated humified air.

Honey

Honey is probably effective in relieving cough symptoms in children over 12 months old and may be as effective as over-the-counter preparations.

The evidence for this is in the Cochrane Review Honey for acute cough in children (April 2018). A simple remedy our grandmothers would endorse. You can read more in my blog Honey for cough in children: can it help?

Garlic

There is a lack of research evidence on the effects of garlic in people with colds.

The Cochrane Review Garlic for the common cold (November 2014) includes only one trial with 146 participants, so we can’t be sure about the potential benefits or harms of garlic for treating or preventing the common cold.

Echinacea

“Echinacea products have not been shown to provide benefits for treating colds, although, it is possible there is a weak benefit from some Echinacea products”.

This was the conclusion of the Cochrane Review Echinacea for preventing and treating the common cold (February 2014). Despite the limited evidence, echinacea is widely used in Europe and North America for common colds.

Find out more: Echinacea for preventing and treating the common cold (Cochrane podcast).

Vaccines

There is currently very limited evidence on the effects of vaccines for preventing the common cold.

The Cochrane Review Vaccines for the common cold (May 2017) which looked at the evidence for potential vaccines found only one study comparing an adenovirus vaccine against placebo. There may be little or no difference between the vaccine and placebo in preventing the common cold, but further research is needed.

References (pdf)

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Lynda Ware has nothing to disclose.



Preventing and treating the common cold: what’s the evidence? by Lynda Ware

is licensed under a Creative Commons Attribution-NoDerivatives 4.0 International

6 Comments on this post

  1. To tell the truth, we can treat and perceive a common cold unseriously, neglecting effective methods of treatment, but this is not a reasonable strategy. You are right that colds can lead to significant time off work and school, as well as other consequences. From my point of view, it is reasonable and important to use some of these methods in aggregate in order to achieve the maximum effect. It is so cool that you mentioned Echinacea because this product is not so widespread, but it can benefit you to a great extent. It is important to apply Echinacea correctly because this product can have a beneficial effect on the immune system, strengthening the body’s defenses. A number of studies have found that Echinacea helps to reduce the severity and duration of colds if it is used immediately after the onset of symptoms. Also, honey is a universal remedy because It includes a maximum of useful components and you are right that it may be as effective as over-the-counter preparations.

    Marina Teramond / Reply
  2. You forgot zinc gluconate which I thought science found the closest thing to a cure so far, allegedly halving symptom intensity and duration. Fact or fiction?

    Daniel / Reply
    • Thanks for your comment. I’ve checked in the Cochrane Library and unfortunately the Cochrane Review on zinc for the common cold has been withdrawn, while some issues that have been raised are addressed. I’m afraid I don’t know when, or whether, this will be available again.
      Best wishes,
      Sarah Chapman [Editor].

      Sarah Chapman / (in reply to Daniel) Reply
  3. There is a therapy: rinse the nose with warm water every 4-6 hours (~49°C). It will kill the viruses – all of them. You can avoid a flu this way or get rid of it within 24-48 hours. It won’t help against cough thoigh. In that case pls. visit the doctor (bit rinse the nose).

    It’s my method. Just add what’s known: Flu viruses die at 40°C – that’s why fever helps. They are deep under the skin, so you need to heat up your nose in the deep. That will not work with air/steam: the blood circulation can carry the heat away, it will not reach the viruses. Water persists staying in the nose, it will transfer the heat and the blood circulation is not fast enough to bring it away. This willmhe heat will kill the Viruses. As long as you stay under 50°C you won’t get hurt – but the viruses can’t survive. That’s it. No business for the pharma industry though…

    Andreas / Reply
    • There’s evidence to suggest that those who took homoeopathic remedies during the Spanish Flu Pandemic of 1919 had higher survival rates than those prescribed the “new” miracle drug of aspirin. One potential explanation is that the homoeopathic remedy did nothing at all….but did at least mean patients stayed off aspirin and its antipyretic effect, which undermined the body’s own defence against viral infection.

      Robert Matthews / (in reply to Andreas) Reply
  4. Just suffered a cold few days ago and yes I must agree that tissue is the best aid during the time. It is really a hassle especially I have tasks to finish. I tried several medicine and steam to make myself feel better – still lasted for couple of days. Just stay hydrated through drinking lots of water, and sipping a warm soup. Hoping that one day, a most effective way to prevent cold will come. Thanks for the information Lynda!

    Will Henss / Reply

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