Capsaicin is the active component of chilli peppers. In cream form it is licensed in the UK as an adjunct in osteoarthritis pain and for neuropathic pain, and it sits on pharmacy shelves under brand names including Axsain and Zacin. It does not work for everyone, does not work quickly, and has a counter-intuitive burning phase that puts patients off if it is not explained properly.
It also has a place. NICE NG226 lists topical capsaicin alongside topical NSAIDs as an option worth considering for knee osteoarthritis where topical NSAIDs are unsuitable or inadequate. This is the practical guide UK pharmacies work from.
Two strengths, two purposes
UK-licensed topical capsaicin preparations come in two strengths:
- 0.025% cream (Zacin) — licensed for symptomatic relief of osteoarthritis
- 0.075% cream (Axsain) — licensed for post-herpetic neuralgia and painful diabetic neuropathy
For joint pain, 0.025% is the relevant formulation. The 0.075% preparation is stronger, designed for neuropathic rather than musculoskeletal pain, and has a more marked initial burning phase.
A separate, much higher-strength 8% capsaicin patch (Qutenza) exists but is a hospital/specialist product and not relevant to community pharmacy.
How it works
Capsaicin activates TRPV1 receptors on sensory nerve endings, initially causing the characteristic burning sensation. With regular application over days to weeks, substance P — a neuropeptide involved in pain transmission — becomes depleted at those nerve endings, reducing pain signalling. The effect is local; systemic absorption from topical use is negligible.
The key counter-level point is that capsaicin does not work like paracetamol. A single application produces burning, not analgesia. Benefit, when it comes, emerges over 1–2 weeks of consistent use three to four times daily.
How to apply
For osteoarthritis pain with 0.025% cream:
- Apply a pea-sized amount to the painful area, three to four times daily
- Rub in thoroughly until absorbed
- Wait at least four hours between applications
- Wash hands immediately after application — unless the treated area is the hand itself, in which case a glove during application is a reasonable compromise
- Do not apply near the eyes, nose, mouth or genitals; capsaicin residue on hands that later touch the face is the single most common cause of unpleasant experiences
- Do not apply to broken or inflamed skin — it will hurt disproportionately and absorption is altered
- Do not cover with an occlusive dressing
- Avoid heat — hot baths, heating pads — over the treated area, as this intensifies burning
What to expect in the first two weeks
- Days 1–3: burning, stinging or warmth at the application site is common, sometimes marked. This is expected and is not a sign of adverse reaction.
- Days 3–7: burning typically reduces as the nerve endings adapt.
- Days 7–14: analgesic benefit, if it is going to emerge, appears here.
- Weeks 2–4: steady state; effect should be assessable.
Patients who stop after one or two applications because of the burning will never see the benefit. Explaining this before they leave the counter is the main thing the pharmacy can do to improve outcomes.
Who it suits and who it doesn't
Capsaicin is a reasonable option for:
- Knee or hand osteoarthritis where topical NSAIDs have not helped or are contraindicated
- Patients wanting to avoid or reduce oral NSAIDs
- Localised pain amenable to a focal application
It is less useful for:
- Hip osteoarthritis — too deep for a topical to reach
- Widespread pain
- Inflammatory arthritis (rheumatoid, psoriatic) — not the primary therapy
- Anyone who cannot commit to three to four applications a day for two weeks
- Broken or eczematous skin
Safety notes the counter should mention
- Capsaicin on the hands contaminates everything they touch — steering wheels, phones, contact lens solution bottles. The eye-rub reaction is memorable.
- Shared towels or bedding can transfer residue. Pillows in particular if hands are treated.
- Breastfeeding: avoid application to the chest or anywhere a baby will come into contact.
- Pets: capsaicin is particularly irritant to dogs and cats if they lick treated skin. Ensure coverings are in place or hands are well-washed.
- Contact lens wearers: glove-on during application is a reasonable habit.
- Mild burning is expected; severe persistent burning, blistering or rash means stop and refer.
How it compares to topical NSAIDs
| Factor | Capsaicin 0.025% | Topical diclofenac / ibuprofen |
|---|---|---|
| First-line for knee OA | Second-line option | NICE-preferred first-line |
| Time to benefit | 1–2 weeks | 1–2 weeks |
| Application frequency | 3–4 x daily | 2–4 x daily depending on strength |
| Systemic absorption | Negligible | 5–10% of oral dose |
| Typical side effect | Local burning | Skin irritation, rare systemic effects |
| Suitable in pregnancy | Limited data — avoid without GP advice | Avoided after 20 weeks |
See our topical diclofenac vs ibuprofen guide for the NSAID options.
When to refer rather than sell
- Sudden severe joint pain with swelling and warmth — refer for assessment
- Systemic symptoms alongside joint pain (fever, weight loss, morning stiffness over an hour) — inflammatory arthritis until proven otherwise
- No improvement after 4 weeks of consistent use — GP review
- Blistering or significant irritation rather than burning
Summary
Capsaicin cream is a niche but useful tool in UK pharmacy pain management. It earns its place when topical NSAIDs have not worked and when the patient understands the burning phase is part of the deal, not a sign of failure. The counter's job is mostly education: set expectations, insist on the full two-week trial, and drill the hand-washing.
Sources
- NICE NG226 — Osteoarthritis in over 16s
- BNF — Capsaicin monograph
- NICE CKS — Osteoarthritis
General information for UK pharmacy customers. If pain is severe, worsening, or accompanied by swelling, consult your pharmacist or GP.