Medicine facts explained

Do you need a prescription for it? Is it a controlled drug? Is it still supplied? For most medicines on this site you will find the answers in the box “Facts about …” under the patient leaflet. Here we explain what each row means.

Some of the same facts appear in a short status line under the name of the medicine at the top of the page. The facts come from two official sources: the NHS Dictionary of Medicines and Devices (dm+d) and the product information published by the MHRA. We do not add medical facts of our own. You can read how often we update them in About this site and our sources.

The facts describe the medicine in general. For your own treatment, follow your doctor or pharmacist and the leaflet in your pack.

The status line

Under the name of the medicine you may see, for example, “Prescription only (POM)”, “Controlled drug (Schedule 3)”, “▼ Additional monitoring”, “No longer supplied”, “Not available” or “Restricted availability”. These are short versions of the rows explained below. A medicine listed as available gets no label. The dm+d is not a record of what is in stock.

Prescription needed?

Every licensed medicine in the UK has one of three legal categories. The category is part of the medicine’s licence:

• Prescription-only medicine (POM) – must be prescribed by a doctor or another authorised health professional and is supplied by a pharmacy or another licensed place.
• Pharmacy medicine (P) – you can buy it without a prescription, but only in a pharmacy and under a pharmacist’s supervision.
• General sale list (GSL) – you can buy it without a prescription in pharmacies and also in other shops, such as supermarkets. Some general sale medicines can only be sold in small packs. For example, a pack of ordinary paracetamol tablets sold outside a pharmacy can hold at most 16 tablets.

New medicines usually start as prescription-only. Once there is enough evidence that a medicine can be used safely without a prescription, the MHRA can move it to a less strict category. Each licence has only one category. Sometimes the packs or strengths on one page have different licences, and so different categories. Then the row says “Depends on the pack or strength” and the status line says “With or without prescription” or “No prescription needed”.

Controlled drug

Controlled drugs are medicines that the law controls more strictly because they can be misused or cause dependence. The Misuse of Drugs Regulations 2001 divide them into five schedules (Northern Ireland has its own regulations). Schedule 1 has the strictest rules and schedule 5 the least strict. The row shows the schedule. Select the row to see what it means for you. For example:

• A prescription for a schedule 2, 3 or 4 medicine is valid for 28 days. Other prescriptions are usually valid for 6 months.
• Prescriptions for schedule 2, 3 and 4 medicines are usually limited to 30 days of treatment. This is good practice, not a legal limit.
• According to GOV.UK, when you leave or enter the UK you must carry medicine that contains a controlled drug in your hand luggage. Take your prescription or a letter from your doctor to show that the medicine is yours. Before you travel, ask the embassy of the country you are going to about its rules.

Active substance, strength, form and how it is taken

• Active substance – the part of the medicine that works. The name links to a page with all the medicines on this site that contain it.
• Strength – how much active substance is in one tablet, capsule or dose, for example 500 mg or 250 mg/5 ml.
• Pharmaceutical form – for example film-coated tablet, oral solution or cream. Below it there may be a description of what the medicine looks like, from the product information for health professionals (the SmPC).
• How is it taken – the route, for example oral (by mouth), cutaneous (on the skin) or intravenous (into a vein).
• Excipients – the other ingredients, for example fillers, colourings or preservatives, from the product information (SmPC). A few of them can matter for some people, for example with an intolerance to lactose. The leaflet then mentions them in section 2.

Pack sizes

These are the pack sizes listed in the dm+d, for example 28 tablets.

Is it available?

What the NHS Dictionary of Medicines and Devices (dm+d) says about the medicine:

• Listed as available – the dm+d does not mark it as discontinued.
• No, all its packs are listed as discontinued – the supplier has stopped supplying every pack.
• No, it is listed as not available – the dm+d marks the product as not available.
• Restricted availability – there are restrictions on prescribing or supplying it. For example, for clozapine the patient, the prescriber and the pharmacy must all be registered with a monitoring service.

The dm+d is not a record of current stock. A discontinued pack may still be available in the supply chain for a while. A medicine listed as available may be temporarily out of stock in your pharmacy. For a medicine listed as discontinued or not available, the row “Still supplied” above the leaflet shows other brands or manufacturers with the same active substance, strength and form. Ask your doctor or pharmacist before you change to a different brand or manufacturer.

When there is a serious shortage of a medicine, health ministers can issue a Serious Shortage Protocol. It lets pharmacists supply an alternative without a new prescription if you agree – see Brand-name and generic medicines.

Shelf life and storage

From the product information (SmPC):

• Shelf life – how long the medicine can be used if the pack is unopened, for example 3 years. The expiry date on your pack (after “EXP”) is the one that applies. For some medicines the time after opening is shorter.
• Storage – for example “Do not store above 25 °C” or “Store in a refrigerator”.

Drug group (ATC)

The group the medicine belongs to in the international ATC classification. It is shown as a tree from the main group down to the active substance. Each level links to a page with the medicines of that group. Above the tree you may also see the type of medicine as the SmPC names it (the pharmacotherapeutic group). How to read the codes is explained in How to read ATC codes.

Additional monitoring

“Yes ▼” means the medicine has the black triangle. It is being monitored even more closely for safety, usually because it contains a new active substance or is a new biological medicine. It does not mean the medicine is unsafe. Report any suspected side effect to the Yellow Card scheme.

This row comes from the dm+d. The dm+d uses the additional monitoring list of the European Medicines Agency (EMA). In the UK, the MHRA keeps its own list, and the EMA list applies in Northern Ireland. So this row can differ from the black triangle in your leaflet. The leaflet in your pack is what counts.

Marketing authorisation and holder

A marketing authorisation is the licence that allows a medicine to be sold. In the UK, the MHRA grants it. The row shows the licence number and, where we know it, when the medicine was first authorised. The letters at the start of the number tell you what kind of licence it is:

• PL – a licence for the whole of the UK.
• PLGB – an older licence for Great Britain. Since 1 January 2025 these licences are also valid for the whole of the UK.
• PLNI – a licence for Northern Ireland only.
• PLPI – a parallel import licence: the medicine was imported from another country (see parallel imports).

The marketing authorisation holder is the company that holds the licence and is responsible for the medicine. Its name and address are also in section 6 of the leaflet.

Codes: GTIN and BNF

• GTIN – the Global Trade Item Number: a number of up to 14 digits that identifies a pack of the medicine. The company that owns the product assigns it.
• BNF – a code that shows where the medicine belongs in the British National Formulary (BNF). The first pairs of digits give the chapter, section and paragraph. For example, 04080100 starts with 04 08 01: chapter 4, section 8, paragraph 1.

What a prescription costs

The box does not show prices. NHS prescriptions dispensed in Scotland, Wales and Northern Ireland are free (special rules apply to prescriptions issued in another part of the UK). In England there is a charge for each item on the prescription, unless you are exempt (you do not have to pay). For example, people who are under 16, aged 16 to 18 and in full-time education, or aged 60 or over are exempt. If you need many items, a prescription prepayment certificate (PPC) can save you money. The charges change from time to time. See NHS prescription charges on nhs.uk.

More guides: How to read a patient leaflet · Glossary · Brand-name and generic medicines · How to read ATC codes

The facts come from the dm+d and the MHRA; this page does not replace advice from a doctor or pharmacist. Last updated 4 November 2026. Found a mistake? Email us at info@patient-info.co.uk.