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A Guide to BENYLIN® Ingredients

BENYLIN® has been one of the UK’s most trusted brands of cough and cold remedies for half a century. Initially developed in the early 1970s, you can now find BENYLIN® products that provide effective relief against multiple cold and flu symptoms.

Here, you can learn more about the active ingredients that make BENYLIN® such a trusted brand for relieving cold and flu symptoms. Discover what each active ingredient does and how it works, along with dosage guidance and potential side effects.

In this guide:


What is guaifenesin?

Guaifenesin is an expectorant. It thins mucus , making it easier to cough up, which helps relieve chest congestion.

Guaifenesin can be used to treat symptoms of various types of coughs and congestion caused by breathing illnesses, bronchitis, and the common cold. It’s typically not used to treat long-term breathing problems such as emphysema or chronic bronchitis, unless directly specified by your doctor.

Guaifenesin side effects

Most people won’t experience side effects from products containing guaifenesin. That said, some rare potential side effects for BENYLIN® Chesty Cough & Cold Tablets , which contains guaifenesin, can include:

  • Stomach upsets.
  • Allergic reactions.
  • Change in heartbeat.
  • Insomnia.
  • Coolness or tingling of the skin.
  • Convulsions, tremors, or nervousness.
  • Raised blood pressure.
  • Raised temperature.

If you do experience any of the above side effects while taking BENYLIN® products containing guaifenesin, you should stop taking the medication immediately and seek the advice of your GP or pharmacist. You can also report any of these side effects using the Yellow Card Scheme – search the Apple App or Google Play store on your smartphone for MHRA Yellow Card or go to Reporting side effects helps to make medicines safer.

Guaifenesin dosage

Before taking any medication containing guaifenesin, you should always read the package instructions and ensure you follow the recommended dosage. You can also contact your GP or a pharmacist if you have any questions about guaifenesin products.

The specific dosage recommended will depend on your age and the product you’re using. As an example, BENYLIN® Chesty Cough & Cold Tablets can be taken at a dose of two tablets every four hours for adults and children over 12, with a maximum dosage of eight tablets every 24 hours. This medication should not be given to children under the age of 12. There are children’s cough medicines within the BENYLIN® range that are suitable for use with those under the age of 12.

BENYLIN® products with guaifenesin

Guaifenesin is used in:


How does paracetamol work?

Paracetamol is a common form of pain relief typically used to deal with mild to moderate pain, such as toothaches, headaches, and sprains. It’s an analgesic and antipyretic, helping to relieve pain and reduce fever , including those caused by a cold or flu.

Paracetamol works by blocking certain chemical messengers in the brain, such as the ones that tell you your body is in pain. It can also alter how chemical messengers work in the area of the brain which regulates body temperature to help reduce a fever. Paracetamol is widely considered safe for most people – including pregnant women and children over 2 months – and has rare side effects.

Paracetamol side effects

In the rare event that side effects from paracetamol occur, they’re usually mild and temporary. That said, you should report them to your GP or online via the Yellow Card Scheme detailed above.

Potential rare side effects from taking paracetamol can include:

  • Rash or swelling due to an allergic reaction.
  • Rapid heartbeat.
  • Rapid heartbeat.
  • Flushing.
  • Blood disorders.

An overdose of paracetamol can lead to failure of the kidney and/or liver, which in severe cases can be fatal. If you overdose or suspect someone has taken an overdose of paracetamol, you should go to your nearest emergency department immediately.

Paracetamol dosage

Always check the included leaflet before taking any medication that contains paracetamol to seek guidance on the correct dosage. For example, with BENYLN® Cold & Flu Max Strength Capsules, adults can take up to two tablets every four to six hours, up to a maximum of eight tablets in 24 hours. However, this may vary with other products depending on the strength of the paracetamol or the other active ingredients, so always read the guidance.

BENYLIN® products with paracetamol

Paracetamol is used in:


What is phenylephrine?

Phenylephrine is a decongestant that helps constrict blood vessels in the nasal passages, helping you to breathe more easily. It works by reducing swelling temporarily in the nose and ears, which can make it easier to breathe through your nose and alleviate discomfort caused by colds, flu , or allergies.

Phenylephrine side effects

As with all medication, some people will experience side effects from products containing phenylephrine, although not everyone will get them. Examples of potential side effects include:

  • Allergic reaction including rashes and hives.
  • Raised blood pressure.
  • Heart palpitations.

Anyone experiencing any side effects, including any not listed above, when taking medications containing phenylephrine should report them. Reporting side effects helps make medications safer. You can tell your doctor or pharmacist or use the Yellow Card scheme.

Phenylephrine dosage

Whenever you take any medication containing phenylephrine, always read the dosage recommendations in the patient information leaflet and follow the instructions.

As an example, for BENYLIN® Mucus Cough & Cold All-In-One Relief Tablets , which contain phenylephrine, the recommended dosage for adults and children over 12 years old is two tablets every four hours. No more than eight tablets should be taken in any 24-hour period, and each tablet should be swallowed whole without chewing. This medication is not suitable for children under the age of 12.

BENYLIN® products with phenylephrine

Phenylephrine is used in:


What is levomenthol?

Levomenthol has mild cooling and decongestant properties that helps soothe a cough and ease congestion in the nasal passages and lungs. Levomenthol can help you breathe more easily by relieving the symptoms of congestion.

Levomenthol side effects

As with all medications, some people may experience side effects from taking medication containing levomenthol. That said, levomenthol is present in products such as BENYLIN® Chesty Coughs Original Medicine in low quantities, meaning side effects and adverse reactions to it are not anticipated. Before use of any levomenthol product, please read the label.

Levomenthol dosage

The exact dosage of levomenthol will vary depending on the medication and factors, such as your age. Always read the patient information leaflet carefully before taking any medicine.

As an example, the recommended dosage for BENYLIN® Chesty Coughs Original Medicine is two 5ml spoonful for adults and children over 12. It should not be taken more than four times a day and isn’t suitable for children below the age of 12.

BENYLIN® products with levomenthol


How does pseudoephedrine work?

Pseudoephedrine is a decongestant that helps constrict blood vessels in the nasal passages, helping you to breathe more easily through your nose. Nasal congestion can be caused by swelling of the blood vessels in the sinuses, which can happen due to allergies, colds, and flu. Pseudoephedrine works by reducing this swelling, which helps air and mucus to flow more freely through the nasal cavity.

Pseudoephedrine side effects

As with all medication, some people may experience side effects from pseudoephedrine. For example, potential side effects of BENYLIN® 4 Flu Tablets , which contains pseudoephedrine, can include:

  • Drowsiness.
  • Headache.
  • Blurred vision
  • Dry mouth.
  • Nausea.
  • Nervousness, dizziness, or insomnia.
  • Thickened mucus.
  • Unusual weakness.
  • Difficulty performing tasks.

If you experience any of the above symptoms while taking this medication, you should stop taking it and consult your doctor or pharmacist. You can also use the Yellow Card online service to report side effects.

Pseudoephedrine dosage

The recommended dose of pseudoephedrine will depend on the type of medication you’re taking. Always read the packaging instructions carefully or ask your pharmacist for advice before taking products containing pseudoephedrine.

As an example, BENYLIN® 4 Flu Tablets can be taken by adults and children over the age of 10. Adults and children aged 16 or over can take up to two tablets every four hours, up to a maximum of four times in 24 hours. Children aged between 10 and 15 can take one tablet every four hours, up to a maximum of four times in 24 hours. This product is not recommended for children aged under 10 years.

BENYLIN® products with pseudoephedrine

Pseudoephedrine is used in:


What is diphenhydramine?

Diphenhydramine is an antihistamine used to treat symptoms of allergies, including sneezing, runny nose, and cough. It can cause drowsiness.

Diphenhydramine is typically combined with other active ingredients, including paracetamol, levomenthol, and pseudoephedrine, when used to treat the symptoms of coughs and colds. It can come in tablet or liquid form. As an antihistamine with drowsy properties, diphenhydramine can also be used to encourage sleep, especially for short-term issues such as sleep deprivation due to persistent cough.

Diphenhydramine side effects

Diphenhydramine can cause some side effects, just like all medication. These are most likely to occur in people over the age of 65. Potential side effects can include:

  • Dry mouth.
  • Dizziness.
  • Feeling unsteady on your feet.
  • Feeling drowsy or sleepy during the daytime.
  • Having difficulty concentrating.

If you experience any of these side effects, you can report them to your doctor or pharmacist, or by using the Yellow Card scheme online.

Diphenhydramine dosage

The recommended dosage of diphenhydramine may vary depending on the type of medication you use and what it’s being used to treat. Anyone over the age of 65 should start with the lowest dose as side effects are more likely. In tablet form, diphenhydramine usually comes in 25mg and 50mg doses. You should always check the patient information leaflet for specific dosage instructions when taking any over-the-counter medication.

BENYLIN® Mucus Cough Night products contain diphenhydramine. For adults and children over 12 years, the recommended dosage of BENYLIN® Mucus Cough Night Syrup is two 5ml spoonfuls. This dose should be taken before bed and then every six hours as required, or up to four times daily. This medicine is not suitable for those under 12 years of age.

BENYLIN® products with diphenhydramine


What is glycerol?

Glycerol acts as a demulcent, a thick substance that forms a soothing film over your throat. Cough syrups commonly contain glycerol because it acts as a thickening agent and can also make the cough medicine more effective. This is because glycerol acts as a humectant and is sweet and lubricating, which may ease sore throats associated with colds.

Glycerol side effects

Glycerol does not have major side effects, although, there could be some potential side effects such as:

  • Nausea.
  • Headaches.
  • Bloating.
  • Dizziness.
  • Diarrhoea.

You may also experience an allergic reaction to glycerol, or another ingredient in BENYLIN® products. If you suspect you’re having an allergic reaction, contact your GP immediately. You can also report any side effects through the online Yellow Card scheme, or to your doctor or pharmacist.

Glycerol dosage

When taking over-the-counter medications containing glycerol, always check the recommended dosage instructions included in the packaging or speak to your pharmacist.

BENYLIN® Dry & Tickly Cough Syrup contains glycerol and is suitable for adults and children over the age of one years old. For children aged one to five, the recommended dose is one 5ml spoonful, which can be repeated three to four times in 24 hours. For children over five and adults, the recommended dose is two 5ml spoonfuls, three to four times daily.

BENYLIN® products with glycerol

Glycerol is used in:


What is Dextromethorphan?

Dextromethorphan is a cough suppressant used to relieve cough symptoms. This ingredient can provide temporary relief from non-productive coughing (without mucus), which may be caused by infections, such as colds or sinusitis. It is not a cure for a cold and will not shorten the duration of the infection, but it can provide relief from the feeling of needing to cough.

Dextromethorphan side effects

As with all medication, products containing dextromethorphan can cause side effects. These are rare but can include:

  • Nausea.
  • Vomiting.
  • Dizziness.
  • Drowsiness.

You can report side effects such as these to your doctor or pharmacist or online using the Yellow Card scheme.

Dextromethorphan dosage

Dosage for dextromethorphan depends on a number of factors, such as your age, the reason you’re taking it, and the medication. Always follow the dosage recommendations on the packaging for any over the counter medications.

BENYLIN® Dry Coughs Syrup contains dextromethorphan. The dosage recommendation for this product is two 5ml spoonfuls up to four times per day for adults and children over the age of 12. This product should not be given to any child under the age of 12.

BENYLIN® products with dextromethorphan

Dextromethorphan is used in:

Ivy leaf dry extract

What is ivy leaf dry extract?

Ivy leaf dry extract is used in some traditional herbal cold and flu medications.

Ivy leaf dry extract side effects

While ivy leaf dry extract is an herbal medicine, it may also cause a number of potential side effects. For example, potential side effects for BENYLIN® Herbal Chesty Coughs Sugar Free Syrup can include:

  • Itchy or red skin.
  • Stomach disorders, including vomiting and diarrhoea.

If you experience these or any other side effects, you should consult a healthcare professional. You can also use the Yellow Card scheme to report side effects from ivy leaf extract online.

Ivy leaf dry extract dosage

It’s important to follow recommended dosage instructions for any medication, which will be included on the packaging. Taken orally, English ivy leaf typically comes in doses of between 300-800mg.

When using BENYLIN® Herbal Chesty Coughs Sugar Free Syrup , the recommended dosage is 4ml, taken two to three times per day. Use the measuring spoon provided.

BENYLIN® products with ivy dry leaf extract