Cocois Ointment for Thick Scalp Scale: Uses, Application and What to Expect
A clinician-reviewed guide to Cocois — the coal tar, salicylic acid and sulphur ointment that softens and lifts thick, stubborn scale in scalp psoriasis and seborrhoeic dermatitis.
Part of the Dandruff & Psoriasis Health Guide.
Key fact: Cocois combines coal tar solution 12%, salicylic acid 2% and precipitated sulphur 4% in a coconut-oil base. It is a keratolytic (scale-softening) treatment — its job is to loosen and lift thick, stubborn scale so the skin underneath can heal and other scalp treatments can actually reach it.
Get Cocois Ointment Online
Access Doctor provides Cocois ointment following a GPhC-regulated online consultation with our pharmacist independent prescribers.
Order Cocois →What is Cocois ointment?
Cocois is a medicated scalp ointment for conditions that produce thick, adherent scale — most commonly scalp psoriasis and seborrhoeic dermatitis, as well as severe dandruff and scaly scalp eczema. Unlike steroid scalp applications, which treat inflammation, Cocois is a descaling (keratolytic) treatment: it softens hardened plaques of scale so they can be lifted away when you wash your hair.
Its three active ingredients are suspended in a coconut-oil base, which is why the ointment feels thick and greasy. That texture is deliberate — the oily base coats and penetrates dense scale far better than a lotion or shampoo can.
12%
Coal tar solution — slows excessive skin cell turnover
2%
Salicylic acid — breaks down and lifts hardened scale
4%
Precipitated sulphur — softens scale and calms flaking
How Cocois works: three actives, one job
Thick scalp scale forms when skin cells are produced faster than they can be shed — the hallmark of psoriasis, and a feature of severe seborrhoeic dermatitis. Each ingredient in Cocois attacks a different part of that problem.
Coal tar solution 12%
Coal tar slows the excessive production of skin cells that builds plaque and scale. It has been used in scalp psoriasis for over a century and remains recommended in UK practice for scaly scalp conditions.
Salicylic acid 2%
Salicylic acid is a keratolytic: it breaks the bonds holding dead, hardened skin cells together, so compacted scale loosens and can be washed away rather than picked or scratched off.
Precipitated sulphur 4%
Sulphur adds a further scale-softening and mild antimicrobial effect, helping to settle flaking and itch.
Why descaling matters: thick scale acts as a physical barrier. Steroid applications such as Betnovate or Dovobet cannot penetrate a dense plaque properly. Cocois is often step one of a scalp treatment plan — clear the scale first, then let the anti-inflammatory treatment reach the skin.
Who Cocois is for
Cocois suits adults and children over 12 (younger children only on clinical advice) with:
- Scalp psoriasis with thick, built-up plaques of scale
- Seborrhoeic dermatitis of the scalp with heavy, greasy scaling
- Severe or stubborn dandruff that medicated shampoos have not shifted
- Scaly scalp eczema where dead skin has become compacted
- Descaling before starting a steroid scalp application, so it can work properly
Diagnosis first: thick scalp scale can be psoriasis, seborrhoeic dermatitis, eczema or, less commonly, a fungal infection — and each is treated differently. If your scalp has never been assessed, get a diagnosis from a clinician before starting treatment. Our prescribers check this during your consultation.
How to apply Cocois: step by step
Cocois is a leave-on-then-wash-out treatment. For severe scaling it is used daily for the first 3–7 days, then reduced; for milder scaling, once weekly is usually enough.
1
Part the hair and apply to the scalp
Work section by section with dry hair, applying the ointment directly to the affected areas of scalp — not the lengths of the hair.
2
Massage in gently
Massage into the scale with your fingertips. Do not scratch or force plaques off — the ointment will soften them for you.
3
Leave on for at least 1 hour — or overnight
The longer the contact time, the better the descaling. For thick scale, apply in the evening, cover with a shower cap and leave on overnight.
4
Wash out with a mild shampoo
Shampoo thoroughly — you may need two washes to remove the oily base. Loosened scale lifts away with the ointment.
5
Repeat to schedule
Daily for 3–7 days if scaling is severe, then drop to once weekly as maintenance, or as your prescriber directs.
Practical tips that make it easier
Time it for the evening
Applying before bed turns the awkward 1-hour-plus contact time into productive overnight treatment.
Protect your bedding
Wear a shower cap and use an old pillowcase — the ointment can stain fabric.
Use a mild shampoo
A gentle or baby shampoo removes the base without stripping or irritating freshly descaled skin.
Comb, do not pick
After washing, a soft comb helps lift loosened flakes. Picking dry plaques can trigger bleeding and new ones.
What to expect: greasiness, odour and results
An honest word about the experience: Cocois is effective, but it is not a glamorous product. The coconut-oil base is thick and greasy, and coal tar has a distinctive tar smell that some people find off-putting. The smell fades once the ointment is washed out, and most people find the trade-off worthwhile once they see compacted scale lifting after the first few applications.
With daily use on severe scaling, expect noticeable softening and shedding of scale within the first week. Remember what Cocois does and does not do: it clears scale, but it does not treat the underlying inflammation of psoriasis. If your scalp is red, itchy and inflamed once descaled, your prescriber may recommend following on with an anti-inflammatory treatment such as Betnovate scalp application or Dovobet gel.
Side effects and safety
Cocois is generally well tolerated. Possible effects include:
- Skin irritation — stinging or redness, more likely on broken or inflamed skin. Stop and speak to a clinician if irritation is marked.
- Photosensitivity — coal tar can make treated skin more sensitive to sunlight. Avoid strong sun on the scalp during treatment and wear a hat outdoors.
- Staining — the ointment can stain fabrics, and may discolour blonde, grey or dyed hair with prolonged use.
- Folliculitis — occasionally, inflamed hair follicles can develop with coal tar products.
Do not apply Cocois to infected, badly cracked or acutely inflamed skin, and keep it away from the eyes. It is not recommended for children under 6, and should only be used in younger children or during pregnancy on the advice of a clinician.
Seek urgent medical attention if you develop widespread pustules (pus-filled spots) on the scalp or body, fever with a rapidly spreading red rash, or signs of scalp infection such as swelling, weeping or severe pain. These need same-day assessment, not a descaling ointment — call 999 in an emergency.
How Cocois compares with other scalp treatments
Cocois occupies a specific slot in the scalp treatment toolkit: it is the descaler. Here is how it sits alongside the other prescription options we cover in this guide series.
| Treatment | Active ingredient(s) | Best for | How it is used |
|---|---|---|---|
| Cocois ointment | Coal tar 12% + salicylic acid 2% + sulphur 4% | Thick, stubborn scale in psoriasis and seborrhoeic dermatitis | Leave on 1 hour or overnight, then wash out; daily for 3–7 days, then weekly |
| Betnovate scalp application | Betamethasone valerate 0.1% (potent steroid) | Inflammation, redness and itch | Applied to the scalp once or twice daily; left on |
| Etrivex shampoo | Clobetasol propionate 0.05% (very potent steroid) | Scalp psoriasis flares | 15-minute contact time, then rinsed out |
| Dovobet gel | Calcipotriol + betamethasone dipropionate | Plaque psoriasis of scalp and body | Applied once daily; left on |
| Ketoconazole 2% shampoo | Ketoconazole (antifungal) | Dandruff and seborrhoeic dermatitis driven by Malassezia yeast | Used in place of shampoo, usually twice weekly |
These are complementary rather than competing options — many treatment plans use Cocois first to descale, then a steroid or antifungal to control the underlying condition. Compare all options in our dandruff and scalp psoriasis treatment options hub.
How to get Cocois online
Access Doctor supplies Cocois ointment through a short online consultation. You answer a set of clinical questions about your scalp condition and medical history; one of our GPhC-registered pharmacist independent prescribers reviews your answers, confirms Cocois is appropriate, and the ointment is dispensed from our UK pharmacy and delivered to your door.
Order Cocois for Thick, Stubborn Scalp Scale
Complete a quick online consultation and, if suitable, our pharmacist independent prescribers will dispense Cocois from our GPhC-registered UK pharmacy with fast delivery.
Order Cocois →Frequently Asked Questions
How long should I leave Cocois ointment on my scalp?
Leave Cocois on for at least one hour before washing it out. For thick, stubborn scale, many prescribers recommend applying it in the evening and leaving it on overnight under a shower cap, then washing it out with a mild shampoo in the morning.
How often should I use Cocois?
For mild scaling, a single application once a week is often enough. For more severe scale, it can be used daily for three to seven days, then reduced to weekly maintenance. Follow the schedule your prescriber recommends.
Does Cocois smell, and will it stain?
Yes — coal tar has a distinctive tar-like smell, and the ointment can stain fabrics and may discolour blonde, grey or dyed hair. Use an old pillowcase or a shower cap overnight, and wash the ointment out thoroughly. The smell fades once the product is washed out.
Can I use Cocois alongside steroid scalp treatments?
Often, yes. Cocois is frequently used first to soften and lift thick scale so that treatments such as Betnovate scalp application or Dovobet gel can reach the skin and work properly. Your prescriber will confirm the right order and timing for your treatment plan.
Is Cocois safe to use in the sun?
Coal tar can make treated skin more sensitive to sunlight. Avoid strong sun exposure on the scalp while using Cocois and wear a hat outdoors if your scalp is exposed, particularly in summer.
Do I need a prescription to get Cocois from Access Doctor?
Cocois is supplied by Access Doctor after a short online consultation. Our GPhC-registered pharmacist independent prescribers review your answers to confirm the treatment is safe and appropriate before it is dispensed and delivered.
If thick scale is the main problem on your scalp, Cocois is the treatment in this cluster built specifically for the job. Start with a consultation, and if a follow-on anti-inflammatory treatment is needed once the scale has cleared, these are the options our prescribers most often pair it with:
Scalp Psoriasis · Rx
Dovobet Gel
Calcipotriol and betamethasone dipropionate gel for plaque psoriasis of the scalp and body.
View product →Scalp Inflammation · Rx
Betnovate Scalp Application
Potent betamethasone valerate 0.1% liquid for inflamed, itchy scalp psoriasis and dermatitis.
View product →References
- NICE Clinical Knowledge Summaries. Psoriasis: management of scalp psoriasis. 2025. cks.nice.org.uk
- NICE Clinical Knowledge Summaries. Seborrhoeic dermatitis. 2025. cks.nice.org.uk
- electronic medicines compendium (emc). Cocois Ointment — Summary of Product Characteristics. medicines.org.uk
- British National Formulary. Coal tar with salicylic acid and precipitated sulfur. bnf.nice.org.uk
- Psoriasis Association. Scalp psoriasis. psoriasis-association.org.uk
Medical disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for diagnosis and treatment. In a medical emergency, call 999.