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Best Over The Counter Sleeping Pills UK


Insomnia is a common sleep disorder characterized by difficulty getting to sleep or maintaining sleep (waking up at night or early in the morning). Sedative antihistamines can be used as a temporary aid to help with sleeping problems.

I will review all over-the-counter sleeping pills (OTC) available in the UK in this post. All of the non-prescription sleeping pills available in the UK contain sedative antihistamines.

Here you can also check out prescription sleeping UK.


What Causes Insomnia?

Many factors can cause insomnia. Some common include stress and anxiety. Changing your sleeping habits should always be considered before trying sleeping pills. There are plenty of online resources, including NHS and Mind websites which offer some excellent tips on improving your sleep.

Quick FAQ

Is it safe to take diphenhydramine every night?
When purchased over the counter, diphenhydramine is used to aid sleeping problems, restricted to 14 days temporarily. Long term effect of diphenhydramine is not fully known.

Over The Counter Sleeping Pills UK: Active Ingredients

All products available over the counter ‘for sleeping’ contain sedative antihistamines as the main active ingredient. Two sedative antihistamines used in the formulation of sleeping pills in the UK are diphenhydramine and promethazine.

Both diphenhydramine and promethazine belong to a group of first-generation antihistamines. The main side effects associated with the use of 1st generation antihistamines are drowsiness and sedation, which is mainly due to the ability f this group of drugs to cross the blood-brain barrier (BBB) and has its effect. BBB typically stops harmful toxins, pathogens, and drugs from reaching the brain.

The second generation of antihistamines, such as loratadine and cetirizine, which can also be purchased over the counter for the treatment of allergies, cross the blood-brain barrier in significantly smaller amounts compared to the first generation of antihistamines.

Dizziness is, therefore, an infrequent side effect of those antihistamines. Generally, the second generation of antihistamines is classified as non-drowsy antihistamines.

Sedative Antihistamines: Common Side Effects

People who take sedative antihistamines may experience side effects.

The table below lists common side effects that may be experienced when taking over-the-counter sleeping pills containing sedative antihistamine. No frequency information is given for promethazine (common / very common / rare).



Fatigue Drowsiness, confusion, dizziness, headaches
Sedation, drowsiness, dizziness Dry mouth and throat, stomach upset
Dry mouth and throat

Tolerance And Addiction

Are over-the-counter sleeping pills addictive?

There is no evidence suggesting that over-the-counter sedative antihistamines such as diphenhydramine and promethazine are addictive. It is fairly safe to buy diphenhydramine and promethazine.

Tolerance of sleeping products

Tolerance to sleeping products
Over-the-counter sleeping pills containing diphenhydramine and promethazine have some role in the short-term management of sleeping difficulties.

However, it has been documented that when used regularly, tolerance develops rapidly

(Vande Griend, Anderson, 2003), Within a few days of starting the treatment.

In simple words, this means that you are less likely to get benefit from the treatment, for example, help in falling asleep when antihistamines are taken regularly.

Over The Counter Sleeping Pills UK: Differences Between Drugs

From the patient’s choice perspective, the main difference between both drugs is the duration of action. There is no strictly defined duration of action for each antihistamine; however, it is estimated that:

  • Sleeping products containing diphenhydramine last between 4-8 hours
  • Sleeping products containing promethazine last between 8-12 hours

The above figures are just an estimate. Patients are usually advised that they may feel sleepy and tired in the morning after taking any of the sedative antihistamines.

Who Should Not Have Over-The-Counter Sleeping Tablets?

The following patients should not take sedative antihistamines:

  • Patients outside of the licensed age group (see details for each specific product)
  • Patients who take monoamine oxidase inhibitors (MOI) or recently stopped taking MOI (in the last 14 days)

Additionally, several ‘cautions’ on the use are related to different conditions, such as asthma, narrow-angle glaucoma, epilepsy, or medication taken, for example, tricyclic antidepressants, like amitriptyline. Please read the product information leaflet or speak to the pharmacist before use for more information.

Where To Buy Over-The-Counter Sleeping Pills UK?

All diphenhydramine and promethazine products are classified as pharmacy-only medicines (P). P products can only be sold from registered pharmacies, including online chemists. P medicines need to be requested from the pharmacy counter as they are not available for self-selection by customers.

What Is The Best Over-The-Counter Sleeping Pill In The UK?

There is no evidence to suggest promethazine is superior to diphenhydramine and vice versa. Both drugs get quickly into the body and cause sedation and drowsiness. Promethazine stays in the body for longer, giving possibly longer sedation time.

With this in mind, Phenergan Night-Time and Phenergan 25mg (each tablet contains 25mg of promethazine) may be the best over-the-counter sleeping pill UK.

The Best Over The Counter Sleeping Pills UK Options

Diphenhydramine contains the best sleeping pills in the UK.

1. Nytol Original and Nytol One a Night

Nytol Original and Nytol One a Night

Nytol is probably the most known brand of over-the-counter sleeping aids. Nytol contains diphenhydramine hydrochloride as an active ingredient.

Nytol Original and One a Night are available only from pharmacies.

Nytol is available in two forms:

  • Nytol Original: each tablet contains 25mg of diphenhydramine hydrochloride.
  • Nytol One a Night: each tablet contains 50mg of diphenhydramine hydrochloride.

Nytol: restrictions on age and duration of the use

Children and adults can use Nytol Original and Nytol One Night over 16 years. Nytol should not be used for more than two weeks without getting advice from a doctor.

Can you use Nytol in pregnancy or when breastfeeding?

Nytol is not recommended during pregnancy. Diphenhydramine is excreted in the breastmilk; however, the effect on infants is unknown. Customers who breastfeed and want to use Nytol need to speak to their GP before using Nytol.

Quick FAQ

What happens if you take more than 1 nytol?
Rhabdomyolysis, convulsions, insanity, toxic psychosis, arrhythmias, coma, and circulatory collapse are possible side effects of large dosage.

2. Nytol One a Night alternative products

Over the counter sleeping - diphenhydramine products

Customers can purchase several equivalent products from different pharmacies which contain 50mg of diphenhydramine. The products listed below are made by the same company (Omega Pharma Ltd), whmakingytol One A Night. Essentially, it is the same drug, packed and marketed for different pharmacies and sold at a considerably lower price:

  • Galpharm One a Night Sleep Aid 50mg Tablets
  • Numark Sleep Aid 50mg Tablets
  • Superdrug One-A-Night Sleep Aid 50mg Tablets
  • Sleepeaze 50mg Tablets
  • Morrisons One-a-Night Sleep Aid 50mg Tablets
  • Tesco Health Sleep Aid 50mg Tablets

The same restriction on the use applies to all products listed above.

3. Nytol Original alternative products

It may be no surprise that the same producer also makes some Nytol Original alternative products. The exact age restrictions and limits on the use apply to all products listed below.

  • Numark Sleep Aid 25mg Tablets
  • Superdrug Sleep Aid 25mg Tablets
  • Sleepeaze 25mg Tablets
  • Asda Night Time Sleep Aid 25mg Tablets
  • Morrisons Sleep Aid 25mg Tablets
  • Tesco Sleep Aid 25mg Tablets

4. Over the counter sleeping aids: Nytol liquid

Although I am reviewing the availability of over-the-counter sleeping pills, I wanted to mention that Nytol, which contains diphenhydramine, is also available as a temporary aid for sleeping problems in the form of liquid. Learn more about Nytol liquid.

5. Panadol Night (Panadol NightPain)

Panadol Night contains two active ingredients: paracetamol and diphenhydramine. It is a pharmacy-only medication licensed for ‘short-term’ treatment of pain experienced at bedtime. A wide range of conditions that cause difficulty in getting to sleep can be managed with Panadol Night, for example:

Panadol Night (Panadol NightPain)

  • Toothache
  • Backache
  • Muscle pain
  • Headache
  • Period pains

There is nothing unusual about this product. Each tablet contains 500mg of paracetamol and 25mg of diphenhydramine (equivalent amount of diphenhydramine to Nytol Original). A maximum of two tablets can be taken at night.

Who can use Panadol Night?

Children and adults can use panadol Night over 16 years of age for the maximum duration of 7 days.

6. Cold and flu products containing diphenhydramine

Several cold and flu cough products contain diphenhydramine to manage cold and flu symptoms to help sleep. These come in the form of tablets or liquid. A familiar brand of cold and flu tablets containing diphenhydramine:

  • Benylin Day & Night Tablets: paracetamol with pseudoephedrine hydrochloride (day tablets) or diphenhydramine hydrochloride (night tablets.
  • Benylin Four Flu tablets: the same combination of drugs as the above product.

Promethazine-Containing, The Best Over The Counter Sleeping Pills UK

Two brands of promethazine for sleep aid products available in the UK are:

  • Sominex
  • Phenergan Night-Time
  • Phenergan (10mg and 25mg)

1. Sominex sleeping tablets

Sominex sleeping tablets

Sominex is a pharmacy-only medication used temporarily as a sleeping aid.

Each Sominex tablet contains 20mg of Promethazine hydrochloride.

Who should not use Sominex?

Patient groups who should not use Sominex (promethazine) include:

  • Patients taking an antidepressant Monoamine oxidase inhibitor (MAOIs) or who recently stopped the treatment with MOI (in the last 14 days)
  • Patients with Central Nervous System (CNS) Depression
  • A patient is allergic to promethazine and any ingredients found in the formulation of Sominex tablets.

Sominex: restrictions on age and duration of the treatment

Sominex is licensed for children and adults who are 16 years or older.

The maximum recommended duration of the treatment is seven days. Patients should seek medical advice if more prolonged use is required.

Can you use Sominex in pregnancy or when breastfeeding?

Women who are pregnant or breastfeeding should speak to their doctor before using Sominex.

2. Phenergan Night-Time sleeping tablets

Phenergan Night-Time sleeping tablets

Phenergan Night Time is another pharmacy-only medication used as a sleeping drug. Phenergan Night Time contains 25mg of promethazine per pill (slightly more than Sominex).

Children and adults can use Phenergan Night Time over 16 years of age.

Children and adults can use Phenergan Night Time over 16 years of age. The same restrictions on the use apply to Phenergan Night-Time as with previously reviewed Sominex. Like Sominex, patients who want to use Phenergan Night time for more than seven days should contact their GP to discuss the treatment.

Can you use Phenergan Night Time during pregnancy or when breastfeeding?

Don’t hesitate to get in touch with your GP for more advice. Generally, Phenergan should not be used in pregnancy unless a GP decides that the treatment is essential.

Quick FAQ

Is Phenergan good for anxiety?
Before or after surgery or other operations, it may be used to assist people in sleeping and regulating their pain or anxiety.

3. Phenergan 10mg and Phenergan 25mg

Phenergan 10mg and Phenergan 25mg

Promethazine is also available as Phenergan 10mg and 25mg tablets. The main active ingredient in both products is promethazine, 10mg per tablet and 25mg per tablet.

Both products are pharmacy-only medicines.

Not all pharmacies may display Phenergan 10mg or 25m on display. You may need to ask a pharmacy team member to get it from the dispensary should you wish to purchase this product.

Phenergan vs Phenergan Night-Time

The first question that can come to your mind is: What is the difference between Phenergan Night and Phenergan? since both products contain the same active ingredient.

Differences in both products related to:

  • Licensed use (what conditions can be treated)
  • Age restrictions on the use
  • Restrictions on the use duration
  • Number of tablets per box
  • Price

The table below highlights the differences between Phenergan Night-Time and Phenergan tablets.

Phenergan Night Time Phenergan tablets
Active ingredient



Amount of active ingredient per tablet


25mg or 10mg

Licensed treatment

Insomnia only

Allergic conditions, antiemetic (to stop nausea), insomnia in children and adults
Age restrictions on the use 16 years and above For insomnia: from 5 years of age*.
Maximum treatment duration 7 days. Seek medical advice after. 7 days. Seek medical advice after.
Number of tablets per box

14 tablets

56 tablets




Price per tablet



* Phenergan Elixir is licensed for children aged 2-5 years.

** Recommended retail price (RRP) taken from C&D (09/2020)

I discussed Phenergan liquid as an antihistamine for children in one of my previous posts.

4. Phenergan alternative products

Generic promethazine 10mg tablets

Generic promethazine 10mg tablets

Promethazine 10mg tablets are available as pharmacy-only medication in a 'generic' form (Genesis Pharmaceuticals). Genesis promethazine has the same licensed use (allergies, anti-sickness, and sleeping aid) age restrictions.

And maximum recommended duration of use as Phenergan tablets.

5. Cold and flu products containing promethazine

Promethazine is used as one of the main active ingredients in a combination of products used to relieve the ‘cold and flu symptoms. ‘Cold and flu’ products containing promethazine come in capsules and liquid.

The most popular brand of promethazine-containing product is Day & Night Nurse Capsules, available as a combination pack (Day Night capsules), Night Nurse Capsules, or Nigh Nurse liquid.

When used as a ‘cold and flu’ product, the ‘night’ capsule contains a combination of promethazine, dextromethorphan (to stop the cough), and paracetamol (reduce temperature, helps with fever symptoms and aches).

Night Nurse equivalent brands, which contain the same active ingredient, include:

  • Fedril Night Cold and Flu, Oral Solution
  • Lloyds Pharmacy Night Cold and Flu Relief, Oral Solution
  • Numark Night Cold and Flu, Oral Solution
  • Boots Night Cold & Flu Relief Oral Solution

Over-The-Counter Chlorphenamine (Piriton) For Sleeping

Can you use chlorpheniramine (brand name: Piriton) as a sleeping aid product? 

Can you use chlorpheniramine (brand name: Piriton) as a sleeping aid product?

Similarly, to promethazine and diphenhydramine, chlorphenamine is classified as 1st generation antihistamine.

As we established earlier, 1st generation antihistamine causes drowsiness and sedation.

Sedation is listed as a very common side effect of chlorphenamine tablets.

In the UK, chlorphenamine is a pharmacy-only medication that can be purchased for the symptomatic management of allergic conditions, such as hayfever, insect bites, or food allergies.

Although chlorphenamine may be of some use to help with insomnia, this use is outside of the product license.

Can You Get Melatonin Over The Counter In The UK?

Melatonin is the most popular sleeping aid product in the USA, available without a prescription. Melatonin is a hormone which is secreted at night in the brain. Melatonin causes fewer side effects (compared to sedative antihistamines) and has been shown to improve insomnia (Costello et al., 2014).

In the UK, melatonin is a prescription-only medication (POM). The most common brand used in the UK is Circadin, which comes in prolonged-release tablets (2mg of melatonin per tablet). The newest POM melatonin to enter the UK market is Slenyto, which also comes in prolonged-release tablets (1mg and 5mg of melatonin per tablet).

Circadin is licensed for short term-management of insomnia in adults over 55 years of age. So far, it has been prescribed (unlicensed use) to treat insomnia in children.

Newly launched Slenyto tablets are licensed for the treatment of insomnia in children and adolescents aged 2-18 with Autism Spectrum Disorder (ASD) and Smith-Magenis syndrome.

Read more about over-the-counter melatonin in the UK.

Are Sleeping Pills For Me?

Sleeping aids may be suitable for some as a temporary solution to their sleeping problem. Long term safety of sleeping products has not been evaluated, hence the restrictions on their use. Few important points to consider before using over the counter sleeping pills:

  • What causes your sleeping problems?
  • Have you tried changing your sleeping habits?
  • Do you have insomnia often?
  • Are you taking any other medication?
  • Do you have any other underlying conditions?
  • Are you aware of other side effects caused by sleeping pills?
  • Are you using sleeping pills regularly?

Always read the product information leaflet before using any over-the-counter medication and speak to your doctor if you have insomnia regularly.

Over The Counter Sleeping Pills: Herbal Products

Customers have an excellent choice of herbal products, which can help with sleeping problems. Herbal remedies are based on traditional use. The most common herb used is valerian. The effectiveness and availability of herbal products in the management of insomnia will be subject to an independent review.

  • Costello RB, Lentino CV, Boyd CC, et al. The effectiveness of melatonin for promoting healthy sleep: a rapid evidence assessment of the literature. Nutr J. 2014;13:106. Published 2014 Nov 7. doi:10.1186/1475-2891-13-106 Available at: https://dx.doi.org/10.1186%2F1475-2891-13-106 Accessed on 05/09/2020
  • Daneman R, Prat A. The blood-brain barrier. Cold Spring Harb Perspect Biol. 2015;7(1):a020412. Published 2015 Jan 5. doi:10.1101/Csh Perspect.a020412 Available at: https://dx.doi.org/10.1101%2Fcshperspect.a020412 Accessed on 03/09/202
  • Vande Griend, Anderson (2003). Histamine-1 receptor antagonism for treatment of insomnia. Available at: https://www.ncbi.nlm.nih.gov/pubmed/23229983 Accessed on 30/03/2019