Topical NSAID gels are one of the most commonly sold pharmacy-only lines in UK community pharmacy. Since NICE updated its osteoarthritis guidance in NG226 (2022, reviewed and retained through 2025), topical NSAIDs have moved from "considered" to first-line pharmacological therapy for knee osteoarthritis — a shift that has visibly changed what pharmacies recommend.

But within the category, the two dominant options behave differently. Diclofenac and ibuprofen gels are both widely stocked, both available without prescription, and both sit behind the counter rather than on the open shelf. Their strengths, dosing and evidence base are not interchangeable.

What NICE NG226 actually says

For osteoarthritis in adults (the dominant reason topical NSAIDs are used), NG226 recommends topical NSAIDs as the first-line pharmacological option for knee OA, and an option for hand OA. Oral NSAIDs are a step up, not a starting point. Paracetamol — long the conventional first line — was downgraded in NG226 after evidence reviews found only modest effect.

The distinction between topical diclofenac and topical ibuprofen is not made explicit in NG226 itself. The guidance is at the category level.

Topical diclofenac — the more potent option

Topical diclofenac in the UK is available to pharmacy (P) at strengths including:

• Diclofenac diethylammonium 1.16% gel (Voltarol Emulgel and equivalents) — apply 2–4 times daily
• Diclofenac diethylammonium 2.32% gel (Voltarol 12-Hour) — apply twice daily

The 2.32% preparation provides sustained release across 12 hours, meaning twice-daily application rather than four times. For patients who will only remember a morning and evening routine, this often translates into better adherence.

Evidence base for topical diclofenac is the larger of the two. Cochrane reviews of topical NSAIDs in acute and chronic musculoskeletal pain consistently find topical diclofenac with the strongest evidence of benefit versus placebo, particularly for hand and knee OA.

Topical ibuprofen — the alternative

Topical ibuprofen is commonly supplied as:

• Ibuprofen 5% gel (Nurofen, Ibuleve and generics) — apply 3–4 times daily
• Ibuprofen 10% gel — twice daily, available in some pharmacy-only formulations

Topical ibuprofen has a smaller, but still positive, evidence base for acute musculoskeletal pain. For chronic OA the evidence is less established than for diclofenac. In UK pharmacy practice ibuprofen is often chosen where a patient has previously responded well to oral ibuprofen, where cost is a factor, or where a 5% formulation is preferred for sensitive skin.

Systemic absorption — the real safety conversation

Topical NSAIDs are not risk-free. Systemic absorption is typically 5–10% of an equivalent oral dose, but that is not zero, and several categories of patient need counter-level questions before supply:

• Known NSAID allergy or aspirin-induced asthma — contraindicated
• Peptic ulcer history — oral NSAID bleed risk is the main concern but topical is not completely exempt
• Renal impairment — caution
• Pregnancy — topical NSAIDs are avoided from 20 weeks; routinely avoided from 30 weeks
• On oral anticoagulants — counsel carefully
• Broken or inflamed skin — do not apply to open wounds
• Eczema — care to avoid worsening irritation

A UK pharmacist will check all of these before supply. Customers asking for 2.32% diclofenac in particular should expect a short conversation before the tube leaves the counter.

When topical NSAID is not the right answer

• Back pain as the primary complaint (NICE NG59 does not recommend topical NSAIDs as a first-line choice)
• Deep joint pain where the area is difficult to cover (hip)
• Inflammatory arthritis pending diagnosis — refer to GP
• Joint with marked swelling, erythema and warmth — consider infective arthritis and refer

How the counter usually decides

See our broader topical NSAID guide for the full category picture.

Application technique — often the missing piece

A counter-level checklist that improves outcomes:

• Apply 2–4 g (roughly a 2–4 cm strip) to the affected joint, rubbing in gently
• Wash hands after application (unless the hand is the treated joint)
• Do not cover with occlusive dressings — systemic absorption rises
• Avoid heat (e.g. heating pads) over the treated area
• Give it two weeks of consistent use before judging effect; topical NSAIDs do not work like paracetamol on a single dose

Oral NSAID for comparison — when to step up

If topical has not helped after a 2-week trial and the indication still fits, oral NSAIDs (with or without a proton pump inhibitor depending on GI risk) are the next step. This is usually a GP decision, particularly in older adults, those with cardiovascular risk, or those on interacting medications.

Summary

Both topical diclofenac and topical ibuprofen work better than placebo and sit inside NICE's preferred first-line category for knee osteoarthritis. Diclofenac has the larger evidence base and a convenient twice-daily 2.32% option. Ibuprofen is often cheaper and familiar. Either is a defensible counter recommendation — the decisive factor is usually adherence to the dosing schedule and the tolerability of the base.

Sources

• NICE NG226 — Osteoarthritis in over 16s
• BNF monographs — Diclofenac sodium, Ibuprofen
• NICE CKS — NSAIDs: prescribing issues

General information for UK pharmacy customers. Choice of topical NSAID should be confirmed with your pharmacist, particularly if you take other medications or have underlying conditions.