⚡ Quick Answer
Seborrhoeic dermatitis is a chronic, yeast-and-inflammation scalp condition treated with antifungal shampoo — ketoconazole 2% (Nizoral) — twice weekly for two to four weeks with a five-minute leave-on, then maintenance every one to two weeks. NHS England rules say GPs do not routinely prescribe it for mild cases. Try OTC for four weeks. If that fails, ask your GP about a topical steroid scalp lotion or Cocois.
Roughly 3 per cent of UK adults have seborrhoeic dermatitis, according to the NICE Clinical Knowledge Summary on seborrhoeic dermatitis last revised in late 2024. If you have spent six months bouncing between supermarket dandruff bottles and watching the flakes come back, this is probably what you have. It is not poor hygiene. It is not dry skin. It is a chronic condition driven by a yeast on your scalp and an immune system that overreacts to it — and the products that work are slightly different from the ones marketed for everyday dandruff. This guide explains what the condition actually is, why your normal shampoo isn’t fixing it, the NHS-recommended treatment plan with technique, when to escalate to a GP, and the lifestyle bits that have real evidence behind them.
What seborrhoeic dermatitis actually is
Seborrhoeic dermatitis is a chronic inflammatory skin condition that turns up on the parts of your body where oil glands cluster — scalp first, but also the sides of the nose, the eyebrows, behind the ears and the mid-chest. Roughly three per cent of UK adults have it. It is more common in men and tends to run between the ages of 30 and 60. As the British Association of Dermatologists puts it, the condition is neither contagious nor a hygiene problem — common assumptions worth getting out of the way early.
The cause has two layers. A yeast called Malassezia lives on most people’s skin and feeds on sebum (skin oil) without causing trouble. In people with seborrhoeic dermatitis, two things are happening at once: the yeast grows in larger numbers, and the immune system overreacts to it. That overreaction is what produces the redness, the swelling and the yellowish greasy scale. So your scalp is misreading a normal lodger as a threat.
This is where the dandruff confusion comes from. Plain old dandruff (pityriasis capitis) is small dry white flakes with no inflammation. Seborrhoeic dermatitis is dandruff plus inflammation — yellowish or greasy scale, redness underneath, persistent itch. They look like cousins from a distance and feel completely different up close.
🤍 PLAIN DANDRUFF Small dry white flakes No inflammation, no redness Mild itch only Responds to mild OTC shampoo | ❤️ SEBORRHOEIC DERMATITIS Greasy yellowish scale Visible redness underneath Persistent itch Often spreads to face/ears, needs antifungal + sometimes steroid |
Triggers and aggravators include stress, fatigue, cold or dry weather, naturally oily skin, immunosuppression (HIV, chemotherapy, biologics, transplant medication) and Parkinson’s disease. Knowing the mechanism matters because the yeast and the inflammation needs different attacks — antifungal first, anti-inflammatory if needed.
Why your normal shampoo probably isn’t working
The reason a £4 supermarket anti-dandruff bottle isn’t fixing this is usually one of two things. Either it does not contain an active ingredient strong enough for an inflammatory condition, or you are not leaving it on long enough for the active to do its job.
The active ingredients with evidence for seborrhoeic dermatitis, in rough order of strength: ketoconazole (an antifungal), selenium sulphide, zinc pyrithione, coal tar, salicylic acid. Mass-market anti-dandruff shampoos use the milder ones at lower concentrations, which are fine for plain dandruff but underpowered for the inflammatory version.
Technique is the other half. Most people apply shampoo, lather for thirty seconds, and rinse. With medicated shampoo, the five-minute soak is doing the actual work, not the rinse. If you have written off ketoconazole or zinc pyrithione because “they didn’t help”, try once more with a phone timer running.
There is also a “natural sulphate-free” myth doing the rounds online. Switching to a sulphate-free shampoo doesn’t help seborrhoeic dermatitis on its own — and if the swap removes the active antifungal ingredient, things often get worse, not better.
The NHS-recommended scalp treatment plan
The NHS-recommended first-line treatment for the scalp is ketoconazole 2% shampoo, available OTC in UK pharmacies as Nizoral 2%. A 100ml bottle is usually £6 to £8. The schedule: twice weekly for two to four weeks. The technique that earns the result: leave the lather on the scalp for five minutes (set a timer), then rinse thoroughly. Once symptoms have settled, drop to a maintenance dose of once every one to two weeks long-term — because this is chronic and relapsing, and stopping completely tends to bring it back within a couple of months.
Honestly, the five-minute soak is the bit most people give up on too early — set a timer and leave it. If you’ve already binned three different anti-dandruff bottles in frustration, ketoconazole 2% is the one to actually finish.
STEP 1
Active treatment phase
Apply ketoconazole 2% shampoo twice weekly for two to four weeks. Lather across the entire scalp — not just the crown — and leave it on for five full minutes before rinsing. This is the phase that knocks the yeast back and calms the inflammation. Don’t skip days or shorten the soak time; the contact time is where the real work happens.
STEP 2
Maintenance phase
Once your scalp is clear, drop to ketoconazole 2% once every one to two weeks as ongoing maintenance. This is chronic and relapsing — stopping completely tends to bring the flaking and itch back within a couple of months. The maintenance dose keeps the Malassezia yeast population suppressed so inflammation doesn’t reignite.
STEP 3
Escalation if needed
If four weeks of correct OTC use hasn’t settled things, book a GP appointment. Your GP can prescribe Cocois ointment (salicylic acid and coconut oil compound) for thick plaques, or a topical steroid scalp lotion such as betamethasone valerate 0.1% or mometasone 0.1% for active inflammation. These are prescription-only options that complement the antifungal shampoo.
If ketoconazole doesn’t suit your hair (it can be drying), the alternatives are selenium sulphide (Selsun), zinc pyrithione at higher concentrations (Head & Shoulders Clinical Strength), coal tar (Polytar) and salicylic acid (Neutrogena T/Gel). They work differently and some people respond better to one than another. Rotating between two on different wash days is a reasonable real-world approach.
For thick yellowish plaques that hang on, a salicylic acid plus coconut oil compound called Cocois ointment is the standard prescription option. Apply overnight, wash out next morning with the antifungal shampoo. Cocois is prescription-only in the UK.
For active inflammation and itch that won’t settle, a short course of a topical steroid scalp lotion — betamethasone valerate 0.1% or mometasone 0.1% — is the next step. One to two weeks then taper. These scalp lotions are GP-prescribed only.
How to actually use ketoconazole shampoo
Wet your hair properly. Squeeze out enough shampoo to lather across the entire scalp, not just the crown. Massage so it makes contact at the hairline and behind the ears, where the condition often clusters. Then put a five-minute timer on your phone and walk away. This is the non-negotiable step. After five minutes, rinse thoroughly.
If your scale is heavy, repeat once in the same wash. Do this twice weekly for two to four weeks. Don’t go daily — daily use just dries the scalp out without giving better outcomes. Once your scalp is clear, drop to once weekly or once every two weeks as maintenance.
Worth knowing: ketoconazole can leave your hair feel a bit dry afterwards. A normal conditioner used on the lengths only, avoiding the scalp, fixes that without compromising the treatment.
When ketoconazole is on the NHS and when it isn’t
The most common question: can my GP prescribe Nizoral. The short answer comes from NHS England’s 2018 guidance, “Conditions for which over the counter items should not routinely be prescribed in primary care”, which is still in force in 2026. Ketoconazole 2% shampoo is on that do-not-routinely-prescribe list for mild seborrhoeic dermatitis precisely because it is widely available OTC at modest cost, the policy logic being that the NHS expects self-care for milder conditions and reserves prescriptions for cases the OTC route doesn’t cover.
💊 NHS prescription rules — OTC first
GPs do not routinely prescribe ketoconazole 2% for mild cases
Under NHS England’s 2018 guidance on conditions for which OTC items should not routinely be prescribed, ketoconazole 2% shampoo sits on the do-not-prescribe list for mild seborrhoeic dermatitis. The policy expects patients to self-care when a treatment is available cheaply in pharmacies. Prescription access is reserved for moderate-to-severe presentations or specific clinical circumstances.
- → OTC ketoconazole 2% used for four weeks without improvement
- → Moderate-to-severe presentation
- → Immunocompromised patients (HIV, chemo, biologics)
- → Concurrent topical steroid scalp lotion needed
The practical move: buy ketoconazole 2% from a pharmacy and run a proper four-week trial with the right technique. If you’re no better in a month, book a GP appointment with a clear treatment history — what you used, how often, how long you left it on, and what changed (if anything). That history is what unlocks the prescription pathway.
Treating the face, ears and chest
When the condition spreads off the scalp, the products change. Antifungal shampoo is for the scalp — applying it to facial skin causes irritation and isn’t designed for that area.
For the classic facial sites — the creases beside the nose, eyebrows, behind the ears — clotrimazole 1% cream is OTC, applied thinly twice daily for two to three weeks. If those patches are red and inflamed too, you can layer a short OTC course of hydrocortisone 1% cream. NICE’s caution is firm: don’t use hydrocortisone on facial skin for more than seven to ten days without GP review, because of skin thinning. Eyebrows respond well to ketoconazole 2% cream where you can get hold of it. The chest takes the same antifungal cream as the face.
Eyelid involvement — red, scaly, gritty lid margins — is a different condition called seborrhoeic blepharitis. Treat that with warm compresses to soften scale and gentle eyelid hygiene scrubs. Do not use antifungal shampoo near the eyes.
When to see your GP
NICE indicators for moving from self-care to a GP appointment:
⚡ Seven signs to escalate to a GP
OTC ketoconazole used correctly for four weeks without improvement — twice weekly, five-minute soak, no meaningful change in flaking or itch.
Severe pain, oozing, weeping or crusted lesions on the scalp that suggest secondary infection.
Sudden, severe flare that is much worse than anything you’ve had before.
Spreading rapidly from the scalp to face, chest or back.
You are immunocompromised — HIV, chemotherapy, biologics, immunosuppressant or transplant medication.
You have Parkinson’s and seborrhoeic dermatitis suddenly worsens — this can be a marker of treatment changes or progression worth flagging.
Significant psychological distress, sleep disruption or hair loss from persistent inflammation.
What your GP can offer beyond what’s available OTC: prescription-strength topical steroid scalp lotion (betamethasone, mometasone), Cocois ointment, prescription ketoconazole, and in rare severe cases under specialist supervision, oral antifungal tablets like itraconazole. NHS Pharmacy First does not currently cover prescription items for seborrhoeic dermatitis, so the route to those stronger options is a GP appointment, not a pharmacist.
Lifestyle and the bits that actually help
Medicated shampoo does the bulk of the work. Lifestyle helps at the margins, but the margins are where flares live.
Stress is a clear trigger — most people notice flares cluster around hard work weeks or family stress. Do whatever stress reduction works for you. Sleep is closely tied to flare severity, so the boring advice — proper sleep hygiene, reduced screen time before bed — is also therapeutic for the scalp. Alcohol can trigger flares for some people; if your scalp gets worse after a heavy weekend, that’s data.
Vitamin D adequacy is worth checking, especially in winter and especially for adults with darker skin or limited sun exposure. NHS guidance is 10 micrograms (400 IU) daily from October to March for the general population. Some studies link low vitamin D to worse seborrhoeic dermatitis severity.
What does not help, despite the noise: gluten-free diets without coeliac disease, “detox” routines, apple cider vinegar rinses. Tea tree oil shampoo has weak antifungal evidence and is fine to try if ketoconazole genuinely doesn’t suit you, but it isn’t first-line.
Frequently Asked Questions
Can I get ketoconazole shampoo on the NHS?
For mild seborrhoeic dermatitis, no — NHS England’s 2018 guidance puts it on the do-not-routinely-prescribe list because it is OTC. Your GP can prescribe it if your condition is moderate-to-severe, if you have used OTC for four weeks with no improvement, or if you are immunocompromised. Bring your treatment history to the appointment.
How long does it take to see improvement?
With correct use — twice weekly, five-minute soak — most people see meaningful reduction in itch and flaking within two to four weeks. If there is no change after four weeks, see your GP. The condition is chronic and relapsing, so even after clearing you will need maintenance dosing every one to two weeks long-term.
Why hasn’t it gone away yet?
Because it is chronic and relapsing — without ongoing maintenance shampoo, most people see it return within months. Treatment controls flares, it does not cure. Stress, sleep, weather and immunosuppression all push relapses too. The goal is keeping symptoms suppressed, not waiting for spontaneous resolution.
Can I use Nizoral every day?
No. Twice a week during the active treatment phase is correct. Daily use just dries the scalp out and doesn’t improve outcomes. Once symptoms settle, once a week or once every two weeks as maintenance is enough to keep the yeast in check.
Is seborrhoeic dermatitis the same as dandruff?
They are related but different. Plain dandruff (pityriasis capitis) is small dry white flakes without significant inflammation. Seborrhoeic dermatitis is dandruff plus inflammation — greasy yellowish scale, redness underneath, more severe itch. The treatments overlap (antifungal shampoos help both) but seborrhoeic dermatitis usually needs higher-strength actives.
Does diet cause seborrhoeic dermatitis flares?
For most people, no — the evidence does not support specific food triggers. Stress, fatigue and weather are the main drivers. Some people notice alcohol makes their scalp worse, particularly after heavier sessions, but blanket dietary restrictions like gluten-free or “anti-inflammatory” diets are not supported by clinical evidence.
The plan is unfussy. Buy ketoconazole 2% shampoo OTC. Use it twice a week for four weeks with a five-minute leave-on. If your scalp is clear at the end of that, switch to maintenance every one to two weeks long-term. If it is still flaky and inflamed after a month, book a GP appointment with your treatment history written down, and ask about steroid scalp lotion or Cocois. Worth saying: this is not a sign you don’t wash your hair enough. It is yeast and immunity, not soap. Manage stress and sleep alongside the shampoo, and you have most of what works.
You might also find our guide to sunscreen SPF 50 NHS guidance for children and our breakdown of hayfever remedies that actually work UK 2026 helpful for managing other seasonal skin and allergy concerns.
