What's in cold and flu tablets, and which ingredients are worth paying for
A cold usually starts to ease within one to two weeks, and no tablet makes it go faster. What cold and flu tablets can do is ease the symptoms while you wait: the aches, the temperature and the blocked nose. This article reads a typical label ingredient by ingredient, so you can see which part of the price pays for a symptom you have.
The medicine rules quoted here are the UK's (NHS and the medicines regulator MHRA). This blog also serves readers in South Africa; where a rule is specific to one country, we name it.
Is there a best cold and flu medicine?
No single product suits every cold, because every cold brings a different mix of symptoms. A tablet with a decongestant does nothing for you if your nose is clear, and a night-time product with a drowsy antihistamine is the wrong choice before a drive. Start from your symptoms, then read the label to see whether the product covers those and nothing you do not need. A pharmacist can help you match the two; that is part of the job at the counter.
What is inside a cold and flu tablet
Most cold and flu tablets, capsules and hot drinks combine two to four of these ingredients.
| Ingredient | What it is for | What to watch |
|---|---|---|
| Paracetamol | Aches, headache, high temperature | It is in most combination products; never add a separate paracetamol tablet on top |
| Ibuprofen | Aches, headache, high temperature | An anti-inflammatory; ask first if you have a stomach ulcer, asthma that reacts to it, or take blood thinners |
| Pseudoephedrine (decongestant) | Blocked nose | Not for everyone with high blood pressure or heart disease; the pharmacist will ask |
| Phenylephrine (decongestant) | Blocked nose | The US regulator questions whether the oral form works (see below) |
| Caffeine | A stimulant added to some daytime products | Count it with your coffee and tea |
| Drowsy antihistamine | Night-time products, to help you sleep | Do not drive or drink alcohol after taking it |
| Vitamin C | Added to many hot drinks | Research shows little effect once a cold has started (see below) |
Paracetamol and the double-dose trap
Paracetamol eases aches and brings a temperature down. It does not unblock a nose or stop a cough. Because it sits in so many cold products, the most common mistake of the season is taking it twice: a cold and flu capsule in the morning, a hot drink at lunchtime and a paracetamol tablet for the headache in the evening. The NHS puts it plainly: do not use other cough and cold medicines if you are also taking paracetamol and ibuprofen tablets. Before you take anything, add up the paracetamol from every product on the kitchen table and compare it with the daily maximum on the leaflet.
Decongestants by mouth
Pseudoephedrine narrows swollen blood vessels in the nose. In the UK it is sold only from the pharmacy counter, and no more than 720 mg can be supplied in one sale without a prescription. In South Africa, ask your pharmacist which products are available. It can raise blood pressure and keep you awake, which is why the pharmacist asks about your health before selling it.
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Compare pricesPhenylephrine is the decongestant in many other products. In November 2024 the US Food and Drug Administration proposed removing oral phenylephrine from its list of approved nasal decongestants, after its review found that the oral form does not work at the usual dose. The proposal does not cover nasal sprays, and it is a US decision: in the UK and South Africa, their own regulators decide what stays on sale. If a blocked nose is your main problem, ask the pharmacist about the options.
Nasal sprays and saline
A decongestant nasal spray (xylometazoline or oxymetazoline) works on the spot, but only for the few days printed on the pack. Used longer, it can leave the nose more blocked than before. A saline spray or rinse has no such limit and is a gentle option for most of the family. The NHS adds that decongestants should not be used by children under 6. Our article on a blocked and runny nose covers sprays in more detail.
Vitamin C and other extras
A large Cochrane review of the trials found that taking vitamin C regularly did not lower the number of colds in the general population and shortened them only slightly. Taken after a cold had started, it showed no consistent effect. If a hot drink with vitamin C costs more than the same drink without it, you are paying for the vitamin, not for relief.
Day and night packs
Many brands sell a combined pack: daytime tablets with paracetamol and a decongestant, night-time tablets with paracetamol and a drowsy antihistamine. Both halves usually contain paracetamol, so the daily maximum covers the day and night tablets together. If you only need help to sleep through a blocked nose, read the night-time label before you buy the whole pack.
Children and colds
Children need medicines made for their age and weight. The NHS sets three rules for the UK: no aspirin for children under 16, no honey for babies under 12 months, and no decongestants for children under 6. Some cough and cold medicines are not suitable for babies and young children at all, so check the age on the pack or ask a pharmacist. For coughs, see our guide to cough syrups for children.
Cold or flu?
Flu tends to start suddenly, with a high temperature, aching muscles and exhaustion, while a cold builds up over a couple of days. The tablets above ease the symptoms of both, but neither antibiotics nor cold remedies treat the flu virus. If you belong to a group at higher risk from flu, contact a doctor early. Our article on flu and cold differences goes through the signs.
Antibiotics do not help a cold
Colds are caused by viruses and antibiotics work only on bacteria. The NHS says GPs do not recommend antibiotics for colds because they will not relieve the symptoms.
When to see a doctor
The NHS advises seeing a GP if:
- you have had a high temperature for more than 3 days;
- your cold symptoms have not improved after 10 days;
- you have had a cough for more than 3 weeks;
- your symptoms are getting worse, or you feel short of breath or have chest pain;
- you have a long-term condition or a weakened immune system.
In South Africa the same signs mean it is time to see your doctor.
How to pay less for cold and flu tablets
The price of a cold comes from three places: the brand on the box, the number of products in the basket and the delivery charge.
- Compare by ingredient, not by brand. A branded combination and a pharmacy own-brand with the same active substances, the same strengths and the same number of tablets can differ in price. The label tells you whether they match.
- Buy only the ingredients for your symptoms. If you only need something for aches and temperature, a plain paracetamol or ibuprofen pack is part of the comparison too.
- Compare the whole basket with delivery. Each online pharmacy sets its own prices and delivery charge. The one with the cheapest tablets is not always the cheapest once the saline spray, the lozenges and the delivery are added.
Bigger packs are not the way to save on painkillers in the UK. Paracetamol tablets are sold in packs of up to 16 in shops and up to 32 in pharmacies, and the MHRA discourages offers that push buyers towards more than one pack.
Our cheap cold medicine page shows how a cold-season basket adds up across online pharmacies. CheaperForDrug is a price comparison, not a pharmacy: comparing is free, with no account and no limit, and prices are checked at the moment you compare. To see why the cheapest pharmacy changes from one basket to the next, read about the cheapest online pharmacy for your basket.
Put your cold-season basket together and compare the total with delivery.
Sources
- NHS: Common cold (page reviewed 22 March 2024)
- MHRA Drug Safety Update: pseudoephedrine and ephedrine, sale restrictions
- MHRA: Best practice guidance on the sale of medicines for pain relief (March 2025)
- Healio: FDA proposes removing oral phenylephrine from nasal decongestants (7 November 2024)
- Cochrane review: Vitamin C for preventing and treating the common cold (2013)
Updated 10 October 2026. This article is general information, not medical advice. Ask a pharmacist or doctor about your own symptoms and the medicines you take, especially if you are pregnant, breastfeeding or have a long-term condition.