Opinion: Which cold and flu remedies work?

Find out which cold and flu remedies are proven to work and which are a placebo.


You can’t escape the jingles at this time of year for cold and flu remedies promising to “fight back at the first sign of sick”. Yet when you visit a doctor for the flu, why don't you leave with a prescription for Codral or Lemsip?

Whenever I’ve had a particularly nasty winter ill, my GPs have all advised a few basics: ibuprofen or paracetamol for aches and pains, nasal sprays for congestion, time off work and bed rest.

If, as the famous jingle goes, with Codral I could “soldier on”, why were my docs holding out on me?

When we've looked at the evidence for these products, we've found most are little more than expensive placebos.

Oral medications such as Codral contain a decongestant called phenylephrine. It’s been studied for more than 50 years, but only half of all trials show it’s effective. There’s better evidence for nasal sprays (such as Otrivin Plus, containing ipratropium bromide). They’re often cheaper too. The downside is you can only use the sprays for three to five days or risk “rebound congestion”, where symptoms return after you stop using the medication.

With the exception of bromhexine (found in chesty cough formulations), the evidence for common ingredients in cough medicines is similarly less than convincing.

The other major ingredient in many cold and flu tablets is paracetamol – but it’s much cheaper bought separately. If you’re like me, you’ll already have a stock in your cupboard.

With the exception of bromhexine (found in chesty cough formulations), the evidence for common ingredients in cough medicines is similarly less than convincing.

Annoying as it can be, there’s not much you can do for a dry cough – and it’s not unheard of for them to linger for up to a month. Sucking a cough drop can soothe your throat, though keep in mind any sugary lolly will do just as good a job as an expensive lozenge.

Despite all the assurances their products work, many pharmaceutical companies have spent big bucks in recent years on clinical trials testing the effectiveness of their cold and flu formulations. None produced any conclusive evidence for the effectiveness of phenylephrine or the cough remedies dextromethorphan and guaifenesin.

So why are these products still moneymakers if there’s questionable evidence they work? Enormous advertising budgets have a lot to do with it. And then there’s the placebo effect, which can do wonders. Your body is also actively fighting the bugs, so you’ll eventually notice improvement whether or not you swallow any pricey potions.

I understand why some people – especially those faced with a house of bunged-up, miserable kids – happily pay for expensive remedies, even if all they get is a figurative sugar pill or syrup. I’d rather save money with a DIY approach, and tell my loved ones that the recommended dose of paracetamol is a “special cold medicine”.

Since that’s unlikely to work on myself, my medicine cabinet’s now stocked with those age-old recommendations: ibuprofen, nasal spray and paracetamol. And for the sake of my Consumer colleagues, I’ll keep any germs I pick up at home.

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24 Jun 2018

Fantastic article and I concur with your findings. The one other element that is scientifically proven to assist with a cold is the use of zinc. It certainly won't help with symptoms, but evidence suggests it will reduce the duration (average of 4 days instead of 5 days) of a cold.

Otherwise like most viral diseases, your best defence is your immune system and getting rest and other stresses on your body while it gets to work such as keeping hydrated (although there's no need to drink excessive water only when thirsty), warmth and rest.

Linda C.
23 Jun 2018
For dry coughs - Fennel or Ginger

For years I have had severe cough problems as a result of sinus/allergy as well as colds occasionally. Unable to sleep for coughing, I sat up with a hot water bottle clutched to my chest as warmth seems to help. Then I accidentally discovered that Fennel works every time - either using fresh plant material to make a hot drink, or chewing on the seeds or leaves. Also, you can buy Fennel seed capsules at health shops, which are easier to use when travelling, or if you don't have a Fennel plant. Ginger tea helps with coughing, but also just chewing on a couple of cubes of crystallised ginger - again discovered by accident, as I use this for indigestion and found I also stopped coughing!

Funnily enough, chewing gum also helps as it keeps your throat lubricated, which I find helps when going on long walks/tramps as it is easy to carry, and lasts longer than a lozenge.

John S.
23 Jun 2018
What about echinacea?

Not for everybody, but it works for us. The secret is to take two tablets the moment you are aware of the early symptoms, then continue with the recommended dose. I find I just need a total of two doses and the cold is usually defeated. We buy the Echinacea with garlic pills from the supermarket.