Diclofenac
In brief
- Low-strength topical diclofenac products are available from pharmacies without a prescription in the UK, while oral, injectable and eye-drop forms are prescription-only medicines. The best-known UK brand is Voltarol.
- Diclofenac is a non-steroidal anti-inflammatory drug (NSAID) used for pain and inflammation, including osteoarthritis, rheumatic pain, acute musculoskeletal pain, and some eye-related inflammatory conditions. It works by inhibiting cyclo-oxygenase (COX) enzymes, reducing prostaglandin production and therefore pain, swelling, and fever.
- The usual adult dose is 50–100 mg orally up to 2–3 times daily, with a maximum of 150 mg per day. For acute pain, a single 50–75 mg dose may be used orally or by intramuscular injection. Topical gel is typically applied at 2–4 g to the affected area 3–4 times daily, and eye drops are usually 1 drop 4–5 times daily depending on the indication.
- Diclofenac is available as tablets, gel or cream, suppositories, injections, eye drops, and spray or patch formulations. It may be taken by mouth, applied to the skin, given rectally, injected intramuscularly or by slow intravenous infusion, or used ophthalmically.
- Diclofenac usually starts working within about 30 minutes to 1 hour when taken by mouth, and topical forms may begin to ease discomfort within a few hours. Injectable forms may act faster, often within 15–30 minutes.
- The duration of action is generally around 4–6 hours for standard oral preparations, which is why repeated dosing is often needed. Extended-release formulations may last longer, and topical products can provide relief over several hours after application.
- Avoid alcohol or keep it to a minimum, as alcohol can increase the risk of stomach irritation, ulceration, and bleeding when taking diclofenac. This is especially important if you are using oral diclofenac or have a history of stomach problems.
- The most common side effects are nausea, indigestion, stomach pain, headache, dizziness, rash with topical use, and sometimes fluid retention or raised blood pressure. Injection-site pain can occur with injectable forms.
- Would you like to try diclofenac without a prescription?
Diclofenac at a glance
- INN (international nonproprietary name): Diclofenac
- Brand names available in the United Kingdom: Voltarol, generic diclofenac
- ATC code: M01AB05
- Forms and dosages: Tablets, gel/cream, suppositories, injection, eye drops, spray/patch
- OTC / Rx classification: Some low-strength topical forms are available from pharmacies without a prescription; oral, injectable, higher-strength topical and eye-drop forms are prescription-only medicines (POM)
- Manufacturers in the United Kingdom: Novartis and other suppliers, plus generics
- Registration status in the United Kingdom: Marketed and approved by the MHRA
What diclofenac is used for
Diclofenac is used for straightforward pain relief that also tackles inflammation.
It is an NSAID, so it is used for joint pain, back pain, muscular pain, swelling and flare-ups that need an anti-inflammatory medicine rather than a simple painkiller.
Diclofenac is the International Nonproprietary Name, and the MHRA-approved UK brand most people recognise is Voltarol.
Low-strength topical forms are available from pharmacies without a prescription, while oral and injectable forms are generally prescription-only.
- Diclofenac
- An anti-inflammatory medicine used to reduce pain and swelling.
- NSAID
- A non-steroidal anti-inflammatory drug.
- Topical
- Applied to the skin, usually as a gel, cream, spray or patch.
- Oral
- Taken by mouth as a tablet or capsule.
- OTC
- Over the counter, without a prescription.
- Rx
- Prescription-only medicine.
Brand names, packaging and forms
In the UK, Voltarol is the best-known brand, supplied as tablets, suppositories, gel tubes and injection, alongside many generics. The active ingredient stays the same whatever the packaging looks like.
Common pack sizes
A diclofenac gel tube is usually the most familiar format for localised pain, while tablets often come in a blister pack and injectables in ampoules or vials.
Common packs include 10g, 20g, 50g and 100g tubes, plus patch products.
Check the route, strength and pack type before use, especially if you are used to a different brand name.
Forms, strengths and choosing the right diclofenac product
Oral tablets and capsules
Tablets and capsules are used when pain is recurring or more general, and the common strengths are 25mg, 50mg, 75mg and 100mg.
These may be film-coated, gastro-resistant or extended-release, depending on how quickly the medicine is meant to act.
The label matters more than the brand name alone.
Topical products
Gel, cream, spray and patch forms are chosen for aches that are easy to localise, such as a sore knee or a strained back.
Topical gel strengths commonly include 1% and 2%.
Special forms
Suppositories, injections and eye drops are less common in everyday self-care, but they are important when swallowing is difficult, pain is acute, or the medicine is needed in a clinic setting.
| Form | Typical strength | Route | Typical use |
|---|---|---|---|
| Tablet | 25mg, 50mg, 75mg, 100mg | Oral | Recurring joint or back pain |
| Gastro-resistant tablet | 25mg, 50mg, 75mg, 100mg | Oral | Patients wanting tablet use with delayed release |
| Extended-release tablet | 75mg, 100mg | Oral | Longer pain control |
| Gel or cream | 1%, 2% | Topical | Localised aches and swelling |
| Suppository | 12.5mg to 100mg | Rectal | Alternative when tablets are unsuitable |
| Injection | 25mg/ml or 75mg/3ml | IM or IV slow infusion | Acute pain in clinical settings |
How diclofenac works and why it is often chosen over other painkillers
It works as an NSAID by reducing inflammation and pain signals, which makes it useful in arthritis pain, muscular pain and other inflammatory aches.
Compared with ibuprofen, naproxen and celecoxib, diclofenac is usually chosen for its established place in anti-inflammatory medicine and its range of oral and topical forms.
How to use diclofenac safely
Adult dosing by form
Safe use starts with the form, because a gel is not taken like a tablet and an eye drop is not used like either.
| Form | Typical adult use | Important note |
|---|---|---|
| Oral tablet or capsule | 25mg, 50mg, 75mg or 100mg depending on product | Follow the product label or prescription exactly |
| Acute pain oral dose | Single 50mg to 75mg dose | Repeat only if advised |
| Injection | Single 50mg to 75mg dose | Used in clinical settings |
| Topical gel | Apply 2g to 4g to the affected area 3 to 4 times daily | Wash hands after use unless treating the hands |
| Eye drops | 1 drop 4 to 5 times daily | Dosing varies by indication |
Children, elderly and higher-risk patients
Children may use oral or rectal forms with weight-based dosing of 1 to 3mg/kg/day in divided doses, but children should only use diclofenac under professional guidance.
Older adults should use the lowest effective dose, because GI, renal and cardiovascular risks need closer monitoring.
Extra caution is also needed in liver or kidney impairment, where dose reduction or avoidance may be appropriate.
If a dose is missed, it should be taken when remembered unless the next dose is nearly due, and double dosing should be avoided.
If an overdose is suspected, urgent medical help is needed, particularly if there are GI disturbance symptoms, CNS effects or signs of renal impairment.
What “lowest effective dose” means
- Missed dose
- Take it when remembered unless the next dose is close.
- Overdose
- Too much medicine taken accidentally or deliberately, needing urgent help.
- Lowest effective dose
- The smallest dose that still controls symptoms well enough.
Side effects
Common, less common and urgent changes
The side effects that people notice first are often mild, but they should still be taken seriously if they do not settle.
- Common mild effects. Nausea, headache, dizziness, indigestion, abdominal pain and topical rash.
- Moderate effects. Fluid retention, hypertension, raised liver enzymes, pruritus and injection-site pain.
- Urgent signs. Worsening stomach upset, blood pressure changes, swelling or symptoms that suggest a liver, kidney or cardiovascular problem.
Someone who feels bloated after starting diclofenac, or who develops a rash after using a gel, should stop and ask for advice rather than pushing through.
Who should not take diclofenac
Do not use, use with caution or ask for advice
Safety screening matters because diclofenac can be very effective, but it is not the right choice for everyone.
| Category | Examples | Practical advice |
|---|---|---|
| Do not use | NSAID hypersensitivity, active gastric or duodenal ulcer, GI bleeding or perforation, severe heart failure, severe liver or kidney dysfunction, third trimester of pregnancy, asthma or urticaria after NSAIDs | Avoid diclofenac and speak to a clinician |
| Use with caution | Controlled hypertension, diabetes, mild to moderate kidney or liver impairment, inflammatory bowel disease, anticoagulation therapy, elderly, CHF, lactation | Use only with professional guidance and monitoring |
| Ask pharmacist or GP | Unclear past reaction to NSAIDs, long-term use, or multiple health conditions | Check before starting or switching products |
Legal status and availability in the UK
Low-strength topical diclofenac products can be bought from pharmacies without a prescription, while oral, injectable, higher-strength topical and eye-drop forms are prescription-only medicines (POM). Some patients are prescribed it on the NHS.
In our online pharmacy, diclofenac is available without a prescription, with discreet delivery to the United Kingdom in 9–21 days.
Topical diclofenac in day-to-day use
How people apply it and why it is so popular
Diclofenac gel is the most familiar form for topical pain relief.
The usual adult amount is 2g to 4g of gel applied 3 to 4 times daily to the affected area.
That makes it easy to target a sore knee, wrist, shoulder or lower back without taking medicine by mouth.
Tube size matters too, because 10g, 20g, 50g and 100g packs suit very different uses, from a short weekend strain to a longer period of local muscle rub use.
| Form | Good for | Convenience | Notes |
|---|---|---|---|
| Gel | Localised pain | Easy to apply | Most common diclofenac gel choice |
| Cream | Small areas | Portable | Simple topical pain relief |
| Spray | Hard-to-reach areas | Quick use | Useful when bending is difficult |
| Patch | Longer wear | Hands-free | Good for people who want a low-fuss option |
Topical treatment is often preferred when someone wants the effect where it hurts, without the stomach upset concerns that can come with oral NSAIDs.
Oral, suppository and injection forms
When each route is chosen
Not every patient wants or can use a tablet, and not every pain episode is suited to a gel.
| Route | Advantage | Limitation | Typical setting |
|---|---|---|---|
| Oral tablets and capsules | Useful for recurring pain | Higher systemic exposure | Home use and prescription treatment |
| Rectal suppositories | Helpful if swallowing is difficult | Less convenient for some people | Alternative administration |
| Injection | Used for acute pain | Needs clinical administration | IM or IV slow infusion in healthcare settings |
Suppositories are available in strengths from 12.5mg to 100mg, while injections are commonly 25mg/ml or 75mg/3ml.
For acute pain, an intramuscular injection can be used in practice, but this is not a consumer self-care product.
Eye drops and other specialist diclofenac products
- Ophthalmic
- Relating to the eye.
- Ophthalmic anti-inflammatory
- An eye medicine used to reduce inflammation.
- ATC S01BC03
- The classification used for diclofenac eye drops.
Diclofenac eye drops are 0.1% and are used for ophthalmic anti-inflammatory treatment, including some eye surgery pain settings.
Because these products are specialist medicines, they are prescription-only and should only be used as directed.
Storage and checking the pack before use
What to look for before the first dose
Good storage keeps the medicine stable and helps patients avoid simple mistakes.
- Store at 15 to 30°C.
- Protect from moisture, heat and light.
- Do not refrigerate topical forms unless the pack says to.
- Keep ampoules and vials in the original packaging.
- Check the batch number, expiry date, strength and route before use.
- Read the patient leaflet and make sure the details match the pack.
Alternatives and when to choose another NSAID
Manufacturers and substitutes
Diclofenac is made by major suppliers such as Novartis, Teva, Sandoz and Mylan, alongside many generics.
Alternatives to Voltarol are usually other NSAIDs such as ibuprofen, naproxen, ketoprofen, piroxicam, celecoxib or etodolac.
People switch because of tolerance, availability or prescription status, and some will prefer a generic diclofenac product if the active ingredient and form suit them better.
| Option | Typical reason to choose it |
|---|---|
| Diclofenac | Established anti-inflammatory effect and broad product range |
| Ibuprofen | Common first-line NSAID option |
| Naproxen | Alternative NSAID for ongoing pain needs |
| Celecoxib | COX-2 selective option in some patients |
The MHRA has restricted the use of diclofenac in people with established cardiovascular disease because of its safety profile.
Delivery across the United Kingdom
| City | Region | Delivery Time |
|---|---|---|
| London | Greater London | 9–21 days |
| Birmingham | West Midlands | 9–21 days |
| Manchester | North West England | 9–21 days |
| Glasgow | Scotland | 9–21 days |
| Edinburgh | Scotland | 9–21 days |
| Leeds | West Yorkshire | 9–21 days |
| Liverpool | North West England | 9–21 days |
| Sheffield | South Yorkshire | 9–21 days |
| Bristol | South West England | 9–21 days |
| Cardiff | Wales | 9–21 days |
| Belfast | Northern Ireland | 9–21 days |
| Nottingham | East Midlands | 9–21 days |
| Leicester | East Midlands | 9–21 days |
| Coventry | West Midlands | 9–21 days |
Key points
Diclofenac remains a well-known NSAID because it combines anti-inflammatory action with practical formats.
The key points are simple: use the lowest effective dose, keep the treatment as short as possible, and ask for advice early if you have ulcer history, asthma after NSAIDs, pregnancy concerns, kidney or liver problems, or troublesome side effects.
