Revealed: The IDENTICAL cold and flu medicines which cost a third of the price

Our investigation looked at the prices of a series of medications at 11 major stores, on the high street and online. We found:

• Shoppers can save up to 71% on IDENTICAL drugs by buying them in a different packet.

• In some cases 'own-brand' products of leading pharmacies Boots and Lloyds cost MORE than identical branded medicines bought elsewhere.

• Shoppers can also save up to 68% on drugs with the same 'active ingredient', by switching from a branded medicine to a generic equivalent.

The findings follow our Branded vs Generic: Cutting the cost of buying over-the-counter medicines report earlier this year, which found major savings were possible across a different range of drugs. For more information on how to cut medicine costs, see our 20 Medicine Savings guide.

IDENTICAL meds, a third of the price

To find identical meds you need to find the 'PL number' – a unique licence number given exclusively to a particular drug made by a particular manufacturer (eg, PL 12063/0104 is a cold and flu remedy). The medicine is sometimes put in different packaging, but if the PL numbers match, it's the SAME drug.

Earlier this month, we compared four sets of identical cold and flu products to see how prices vary depending on which company sells them. We looked for the cheapest price we could find for each drug, in store and online where possible, at Asda, Boots, Home Bargains, Lloyds, Poundland, Poundstretcher, Sainsbury's, Savers, Superdrug, Tesco and Wilko.

We excluded independent pharmacies from the research as pricing can vary widely, and internet pharmacies due to the cost of delivery if you're not bulk-buying – though these are worth factoring in if you're buying, as they can be competitive.

Here are the prices we found for brands and identical own-brand equivalents at four major chains – these include the cheapest and most expensive overall in each case:

How the identical medicines compare by price

Shockingly, in most cases we found Boots' and Lloyds' 'own brands' were more expensive than identical branded products we found sold in different stores.

A spokesperson for Boots insisted it offers "competitive pricing on both branded and own label products". And a Lloyds spokesperson said: "We are are unable to control the pricing of branded products in other retailers but endeavour to maintain our competitiveness versus the market".

Both said they also have trained healthcare staff.

Revealed: The IDENTICAL cold and flu medicines which cost a third of the price

Pay up to 70% less for the same active ingredient

Even if there's not an identical medicine that's cheaper, it's often possible to save by swapping branded products for a generic – unbranded or own-brand – equivalent.

It's a medicine's 'active' ingredient that matters – the rest is largely irrelevant (unless you've certain allergies), though liquid capsules work quicker and some taste different. Professor Jayne Lawrence, chief scientist at the Royal Pharmaceutical Society, said: "If the active ingredients, the dose and the formulation are the same, then medicines will have the same effect, whether they are a well-known brand or an unknown generic".

To see how much you can save on drugs with the same active ingredient, we looked at the same set of stores and compared five cold, flu and fever branded products (at the cheapest price we could find) with their cheapest generic counterparts we could find:

Branded vs generic medicines

While generic equivalents usually beat branded medicines on price and have the same active pharmaceutical ingredient, it's important to note other ingredients can differ. Make sure you're aware of any possible allergic reactions and ensure the medication you choose is correct for you – if in doubt, check with the pharmacist or your GP.

A spokesman for Reckitt Benckiser, which includes the Nurofen and Lemsip brands, said: "Even if formulations and formats of products seem to be the same, the finished product can still have differences. This is due to additions to the active ingredient which can influence factors such as taste, feel and ease of use of the overall product.

"Brands can also be more expensive due to investment in research and product innovation. Unlike manufacturers of generic medicines, Nurofen for Children and Lemsip continue to invest significantly in research and development and proprietary manufacturing processes to bring new products to market to satisfy consumer needs."

The Proprietary Association of Great Britain, which represents the branded over-the-counter medicine industry, argued that branded medicines are often first to the market and so their producers carry higher development costs than those that follow.