From cough syrup to cold-sore cream, the mainstays of your medicine box that may not be as good as you think (and why a banana skin is a good replacement for one common cure!)

They’re the common cold remedies most of us have in our bathroom cabinets. But last week, over-the-counter products such as Lemsip, Sudafed and Beechams were at the centre of an unlikely controversy after the US Food and Drug Administration proposed removing some of the products from sale over mounting evidence that one of the main ingredients, a decongestant called phenylephrine, doesn’t work when given orally.

Professor Ron Eccles, former head of the Common Cold Centre at Cardiff University, said phenylephrine was an ‘ineffective medicine’ and products containing it should also be ‘taken off the shelves’ in the UK.

It prompted uproar on social media. Some blasted pharmaceutical companies for selling ‘snake oil’, while others who rely on the ‘miracle drug’ products said they were the ‘only thing’ which helped unblock a stuffed nose.

It’s a timely debate at the start of the nation’s cold and flu season, with scientists predicting a ‘tripledemic’ outbreak of Covid, influenza and respiratory syncytial virus (RSV).

But it also reveals a curious theme when it comes to many of the popular treatments in pharmacies or from supermarket shelves – they’re a godsend for some, while others claim they have little effect. Why is there so much disagreement?

The simple explanation is, according to experts, that many of the products we rely on to treat cold sores to coughs are only ‘minimally effective’ – and, in some cases, they’re little more than a placebo.

All such products are approved and licensed as safe and effective medicines by the medicines regulator, the MHRA.

But, as Dr Hisham Al-Obaid, a lecturer in pharmacy at the University of Reading, said: ‘There are quite a few over-the-counter treatments where [there] is not that much evidence that they work – and, quite often, there are other, much cheaper ways of treating them yourself.’

Some offer only limited relief, without tackling the underlying cause. Others target minor ailments which would disappear naturally by themselves.

Here are five other treatments that are likely to be in your home but which might not quite do what you think…

Ditch the cough syrup for honey and lemon 

What is it? Used by millions, these syrups claim to soothe sore throats and reduce coughing. The global market for cough medicines was worth more than $5billion (£3.9bn) last year. There are a variety of options available, with different ingredients.

This Benylin product contains glycerol and sucrose which, according to its ads, ‘coats your throat and helps reduce the urge to cough’, and ‘relieves irritated and sore throats’.

Expert verdict: There is very limited, good-quality evidence that cough syrups actually make your cough better.

Glycerol, a naturally occurring alcohol, and sucrose, a type of sugar, are known in science as having ‘demulcent’ properties, which means they form a protective film that can relieve inflammation or irritation. But a review in 2017 found ‘no published evidence’ on its efficacy as a cough treatment.

Other cough syrups contain active ingredients such as guaifenesin, which loosens mucus and makes it easier to cough, or dextromethorphan, which blocks the cough reflex in the brain and means you cough less.

But the evidence is contradictory, says GP Dr Philippa Kaye.

‘The evidence is very mixed for the benefits of various types of cough medicine,’ she says. ‘Some studies find they reduce the severity and frequency of coughs, while other studies find no additional benefit compared to a placebo. But there is good evidence that honey and lemon in warm water, which has both an antiseptic and lubricating effect on the throat, is effective.

‘So if you’re using a cough syrup that’s just glycerol and sucrose, honey will probably work just as well and cost less.’

Gels which don’t cure a cold sore

What is it? Cold sores are common, but painful blisters which appear on the face, often on the lips, are caused by the herpes simplex virus.

They can be hard to shift – one in five people has a recurring problem. This Bonjela gel contains choline salicylate – an anti-inflammatory pain reliever, related to aspirin – and cetalkonium chloride, an antiseptic.

Bonjela claims its gel ‘helps stamp out germs, quickly soothes, and reduces swelling’, and provides ‘effective pain relief in just three minutes’.

Expert verdict: While these gels will provide some relief by reducing inflammation and pain, they won’t cure your cold sore, says Penny Ward, visiting professor in pharmaceutical medicine at King’s College London.

Choline salicylate is commonly used as a pain reliever for other conditions including gout and rheumatoid arthritis, and cetalkonium chloride can help to treat these infections. But Professor Ward says: ‘All Bonjela is doing is dealing with the pain of a cold sore rather than killing the virus.

‘It’s soothing, but you’re better off using something containing acyclovir cream, like Zovirax, which is an anti-viral.’

Studies suggest acyclovir creams can make cold sores go away about one day sooner and may reduce the severity of symptoms.

But even these won’t prevent further outbreaks or stop the spread to others.

‘Ultimately, cold sores are uncomfortable for a few days but they will eventually disappear by themselves,’ says Dr Al-Obaidi. ‘So it’s up to you if you’re happy for nature to take its course or not. You won’t notice much difference either way.’

Soothes piles but it can’t clear them

Anusol Cream, 23g, £4.60 from Boots

What is it? They’re the painful lumps in and around the anus which affect around four out of five people at some point in their lives.

Causing irritation, inflammation, bleeding and an intense itch, haemorrhoids – known as piles – are swollen blood vessels which may form because of too much pressure from constipation, pregnancy or heavy lifting. The three-way action Anusol cream contains zinc oxide, Balsam of Peru and bismuth oxide. The product says it ‘shrinks piles, relieves discomfort and soothes itching’.

Expert verdict: The main problem with these creams is they won’t actually get rid of your haemorrhoids, according to Professor Ward.

Anusol does offer relief from symptoms. Zinc oxide acts like a barrier to protect the skin around the anus, and it has a soothing effect and may reduce some of the inflammation.

Bismuth oxide is an antiseptic which protects raw areas around the anus from infection. Balsam of Peru is also a mild antiseptic – though it can trigger an allergic response known as contact dermatitis.

Experts say there are no large, good-quality clinical studies concluding that these products can hasten the disappearance of haemorrhoids.

‘Ideally you at least want one which contains hydrocortisone, a steroid, which will definitely reduce the itch and the irritation around the anus,’ Professor Ward says. ‘Some others also contain lidocaine which is as an anaesthetic, which reduces pain.’ However, prolonged use of any creams containing steroids can also thin the skin – leading to further irritation.

AnuSol said its cream was licensed ‘for the symptomatic relief of uncomplicated internal and external haemorrhoids’.

Taking steps to prevent piles from initially developing is also crucial – the NICE guidance prioritises lifestyle advice and simple painkillers over ‘considering’ the use of over-the-counter skin creams.

‘It’s important to ensure you’re not constipated, by increasing your fibre intake with plenty of fruit and veg and wholegrains, and drinking enough fluids,’ Dr Kaye says.

‘You might need a fibre supplement, like ispaghula husk, and to get some exercise to keep things moving.’

Importantly, any bleeding from the bottom should always be checked by a GP.

Bite creams that can cause bad reactions

What is it? Anthisan is a staple for applying to bites and nettle stings. The active ingredient is mepyramine maleate, an antihistamine which blocks the body’s immune response to any allergen. Anthisan says its product provides ‘effective relief from pain, itching and inflammation caused by insect bites, insect stings and nettle rash’.

Expert verdict: A review by the Drugs and Therapeutics Bulletin in 2012 found such creams, known as topical antihistamines, are ‘generally not recommended’ and the British National Formulary says they’re only ‘marginally effective’ and sometimes cause skin reactions.

They do not specifically refer to mepyramine maleate, which is the same antihistamine used in a bite cream produced by high street pharmacy Boots – just such creams in general.

But it remains the case that there is little evidence for the effectiveness of any topical antihistamine for insect bites, and in rare cases they may themselves lead to swelling.

The latest advice to GPs is that they have ‘uncertain value’ and that the evidence was ‘lacking’ for the use of any antihistamine – including tablets – and for steroid creams.

But NICE does recommend ‘simple first aid’ if someone has a reaction to a bite, which might include painkillers, an antihistamine tablet and steroid cream.

Dr Al-Obaidi says: ‘The problem with topical antihistamines is that the active ingredient doesn’t absorb into the skin very well and, for most people, taking a tablet will work better to reduce inflammation and itching.’