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Dermax Therapeutic Shampoo – 250ml

Dermax Therapeutic Shampoo – 250ml

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  • ✔️ Targets dandruff and seborrhoeic dermatitis at the scalp
  • ✔️ Benzalkonium chloride 0.5% reduces scalp microbial overgrowth
  • ✔️ Visible reduction in flaking and itching within weeks
  • ✔️ Suitable for adults and young people aged 12 and over
  • ✔️ Convenient 250ml bottle for regular twice-weekly use

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Is Dermax the Right Therapeutic Shampoo for Scalp Conditions?

 

Scalp problems like dandruff and seborrhoeic dermatitis are far more common than many people realise. The NHS estimates that dandruff affects around half of all adults at some point in their lives, causing flaking, itching, and sometimes embarrassment. If over-the-counter cosmetic shampoos haven't made a dent, it might be time to try something more targeted. Dermax Therapeutic Shampoo 250ml is a medicated option designed specifically to address these persistent scalp concerns, and you can find it alongside other hair care products at Cured Pharmacy.

Dermax contains benzalkonium chloride 0.5% as its active ingredient — an antiseptic compound with well-established antimicrobial properties. It works by reducing the population of microorganisms on the scalp that contribute to flaking and irritation. Unlike everyday shampoos, this is a therapeutic shampoo for scalp conditions formulated to do a specific clinical job, not just cleanse.

 

How Does Dermax Therapeutic Shampoo Work on the Scalp?

 

The mechanism behind Dermax is straightforward. Benzalkonium chloride is a quaternary ammonium compound that disrupts the cell membranes of bacteria and fungi on the scalp surface. Seborrhoeic dermatitis, in particular, is linked to an overgrowth of Malassezia yeast — a naturally occurring fungus that, when present in excess, triggers inflammation and flaking. By reducing microbial load, Dermax helps restore a healthier scalp environment.

  • Benzalkonium chloride disrupts microbial cell membranes on contact
  • Reduces Malassezia yeast overgrowth associated with seborrhoeic dermatitis
  • Decreases scalp inflammation, itching, and visible flaking
  • Creates a less hospitable environment for recurrence of symptoms

 

Who Should Use Dermax Therapeutic Shampoo?

 

Dermax is suitable for adults and young people over 12 years of age who are experiencing dandruff or seborrhoeic dermatitis of the scalp. It's particularly useful if standard cosmetic anti-dandruff shampoos have failed to provide lasting relief. That said, it's not appropriate for everyone — and knowing whether it's right for you matters.

  • Adults with persistent dandruff unresponsive to cosmetic shampoos
  • People diagnosed with seborrhoeic dermatitis of the scalp
  • Those seeking an OTC medicated option before pursuing prescription treatment
  • Individuals aged 12 and over (not recommended for younger children without medical advice)

If you have a history of skin conditions such as psoriasis, or if your scalp is broken or severely inflamed, speak to your GP or pharmacist before starting Dermax. It's also worth exploring our skin care range if you're managing related skin concerns alongside scalp symptoms.

 

How Does Dermax Compare to Other Medicated Shampoos?

 

Feature Dermax Therapeutic Shampoo Selenium Sulphide Shampoo (e.g. Selsun)
Active ingredient Benzalkonium chloride 0.5% Selenium sulphide 2.5%
Primary action Antiseptic / antimicrobial Antifungal / cytostatic
OTC availability Yes Yes (lower strengths)
Suitable for ages 12 and over Adults (varies by product)

 

Is Dermax Therapeutic Shampoo Safe to Store at Home?

 

Yes — Dermax Therapeutic Shampoo is straightforward to store safely at home. Keep it below 25°C, away from direct sunlight, and out of reach of children. Do not store it in the bathroom if the room gets very humid, as moisture and heat can affect the product over time. Always check the expiry date before use and do not use the shampoo past this date.

This product is a medicine. Speak to your doctor or pharmacist before using if you have an underlying medical condition or are taking other medicines.

Dermax Therapeutic Shampoo 250ml specifications
Treatment category Scalp conditions — dandruff, seborrhoeic dermatitis
Mechanism of action Antiseptic; reduces microbial load on the scalp via benzalkonium chloride
Effective for Dandruff, seborrhoeic dermatitis of the scalp
Suitable for Adults and children aged 12 and over
Active ingredient Benzalkonium chloride 0.5%
Pack size 250ml
UK classification General Sale / OTC
Drug class Antiseptic / antimicrobial
Preparation Medicated shampoo (liquid)
Route of administration Topical (scalp)

Specifications of Dermax Therapeutic Shampoo 250ml

 

What Is Dermax Therapeutic Shampoo and What Is It Used For?

 

Dermax Therapeutic Shampoo 250ml is a medicated scalp shampoo containing benzalkonium chloride 0.5% as its active ingredient. It is used to treat dandruff and seborrhoeic dermatitis — two of the most common scalp conditions in the UK. Dandruff presents as white or yellowish flakes of skin shed from the scalp, often accompanied by itching. Seborrhoeic dermatitis is a more inflammatory condition that can cause redness, greasy scaling, and persistent irritation. Both conditions are linked to an imbalance of microorganisms on the scalp, which is where Dermax's antiseptic action becomes relevant. It is available over the counter without a prescription and is classified as a general sale medicine in the UK.

 

What Do You Need to Know Before Using Dermax Therapeutic Shampoo?

 

Before using Dermax, it's important to check whether it's appropriate for your situation. There are certain circumstances where you should not use this shampoo, or where you should seek advice first.

Do not use Dermax if you:

  • Are allergic to benzalkonium chloride or any other ingredient in the formulation
  • Have open wounds, cuts, or severely broken skin on the scalp
  • Are under 12 years of age (unless directed by a doctor)

Speak to your pharmacist or GP before use if you:

  • Are pregnant or breastfeeding
  • Have a history of skin conditions such as psoriasis or eczema affecting the scalp
  • Have previously had an allergic reaction to antiseptic products
  • Are using other topical scalp treatments at the same time

Known drug interactions:

  • No significant systemic drug interactions are currently documented for topical benzalkonium chloride at this concentration
  • Avoid using alongside other medicated scalp products unless advised by a healthcare professional, as combined use may increase the risk of irritation

 

How Should You Use Dermax Therapeutic Shampoo?

 

Using Dermax correctly is key to getting the most from it. Follow these steps each time you wash your hair with this shampoo.

  1. Wet your hair and scalp thoroughly with warm water
  2. Apply a sufficient amount of Dermax Therapeutic Shampoo directly to the scalp
  3. Massage gently into the scalp using your fingertips — avoid vigorous rubbing
  4. Leave the shampoo in contact with the scalp for 3–5 minutes
  5. Rinse thoroughly with warm water
  6. Repeat the application if desired, then rinse again
  7. Avoid contact with eyes; if contact occurs, rinse immediately with plenty of water
Indication Age Group Dose Frequency
Dandruff Adults & children 12+ Sufficient amount to cover scalp Twice weekly
Seborrhoeic dermatitis Adults & children 12+ Sufficient amount to cover scalp Twice weekly (reduce to once weekly when controlled)

If you're also managing skin concerns elsewhere on the body, you may find our creams and ointments collection useful for complementary topical treatments.

 

What Are the Possible Side Effects of Dermax Therapeutic Shampoo?

 

Like all medicines, Dermax Therapeutic Shampoo can cause side effects, although not everyone experiences them. Most side effects are mild and localised to the scalp.

Common side effects:

  • Mild scalp irritation or tingling during or after use
  • Temporary dryness of the scalp or hair
  • Slight redness at the application site

Less common side effects:

  • Allergic contact dermatitis (rash, itching, or swelling of the scalp or face)
  • Burning sensation that persists after rinsing
  • Hair texture changes with prolonged use

If you experience signs of an allergic reaction — such as swelling of the face, lips, or throat, or difficulty breathing — stop using the product immediately and seek urgent medical attention. For concerns about hair loss alongside scalp conditions, our female hair loss collection may offer additional support options.

 

How Should You Store Dermax Therapeutic Shampoo?

 

  • Store below 25°C in a cool, dry place
  • Keep away from direct sunlight and sources of heat
  • Do not store in a steamy bathroom environment if possible
  • Keep the cap tightly closed when not in use
  • Keep out of the sight and reach of children
  • Do not use after the expiry date printed on the bottle
  • Do not dispose of medicines via wastewater or household waste — return unused product to your pharmacy

Written and reviewed by our qualified team

Your safety and success are our highest priorities. Our medical team rigorously evaluates every product and piece of advice we provide, ensuring you receive only the most effective, science-backed solutions available.

Frequently Asked Questions

Where can I buy Dermax Therapeutic Shampoo online in the UK?

You can buy Dermax Therapeutic Shampoo 250ml directly from Cured Pharmacy, a GPhC-registered UK online pharmacy, for just £8.49. It is available without a prescription as an over-the-counter product. Browse our full hair care collection for related products.

How does Dermax Therapeutic Shampoo work in the body?

Dermax contains benzalkonium chloride 0.5%, an antiseptic that works by disrupting the cell membranes of bacteria and fungi on the scalp surface. This reduces the microbial overgrowth — particularly Malassezia yeast — that drives dandruff and seborrhoeic dermatitis. Because it acts topically, it does not enter the bloodstream in meaningful amounts under normal use.

How do I use Dermax Therapeutic Shampoo step by step?

Wet your hair thoroughly, apply a generous amount of Dermax to the scalp, and massage in gently with your fingertips. Leave it on for 3–5 minutes before rinsing thoroughly with warm water. You can repeat the application in the same wash if needed, and use it twice weekly for best results.

How often should I use Dermax Therapeutic Shampoo?

During the initial treatment phase, Dermax is typically used twice a week. Once your symptoms are under control, you can reduce frequency to once weekly as a maintenance routine. Always follow the instructions on the label or as directed by your pharmacist.

How long does it take for Dermax Therapeutic Shampoo to work?

Most people notice a visible reduction in flaking and itching within 2–4 weeks of consistent twice-weekly use. Individual results vary depending on the severity of the condition and how regularly the shampoo is used. If there is no improvement after 4 weeks, consult your pharmacist or GP.

What are the side effects of Dermax Therapeutic Shampoo?

Side effects are uncommon but can include mild scalp irritation, temporary dryness, or a slight tingling sensation during use. Less commonly, some people may experience allergic contact dermatitis, presenting as redness, itching, or swelling. If you notice any signs of a serious allergic reaction, stop use immediately and seek medical attention.

Who is Dermax Therapeutic Shampoo suitable for?

Dermax is suitable for adults and young people aged 12 and over who have dandruff or seborrhoeic dermatitis of the scalp. It is not recommended for children under 12 without medical supervision, or for use on broken or severely inflamed skin. If you have an underlying skin condition such as psoriasis, speak to your GP before use.

Can I use Dermax Therapeutic Shampoo if I am pregnant or breastfeeding?

If you are pregnant or breastfeeding, it is advisable to speak to your GP or pharmacist before using Dermax Therapeutic Shampoo. Topical benzalkonium chloride at this concentration is generally considered low-risk, but professional guidance is always the safest approach during pregnancy and lactation. Do not self-treat without checking first.

Can I use Dermax Therapeutic Shampoo alongside other scalp treatments?

Using Dermax alongside other medicated scalp products is not generally recommended without professional advice, as combining treatments may increase the risk of irritation or dryness. If you are already using a prescribed scalp treatment, speak to your pharmacist before adding Dermax to your routine. They can advise on the safest approach for your specific situation.

What happens if I accidentally get Dermax Therapeutic Shampoo in my eyes?

If Dermax comes into contact with your eyes, rinse them immediately and thoroughly with plenty of clean, lukewarm water for several minutes. Benzalkonium chloride can cause eye irritation, so prompt rinsing is important. If irritation persists after rinsing, seek medical advice promptly.

Is Dermax Therapeutic Shampoo the same as a selenium sulphide shampoo?

No — Dermax and selenium sulphide shampoos are different products with different active ingredients. Dermax uses benzalkonium chloride 0.5% as an antiseptic, while selenium sulphide shampoos (such as Selsun) use selenium sulphide as an antifungal and cytostatic agent. Both treat dandruff and seborrhoeic dermatitis, but through different mechanisms, and one may suit you better than the other depending on your scalp's response.

What are the alternatives to Dermax Therapeutic Shampoo?

Alternatives include selenium sulphide shampoos, ketoconazole shampoos (such as Nizoral), zinc pyrithione-based shampoos, and coal tar preparations. The right choice depends on the severity of your condition and any previous treatments you've tried. Your pharmacist can help you compare options — and if you're also dealing with fungal skin concerns, our athletes foot and fungal infections range may be relevant too.

How long can I keep using Dermax Therapeutic Shampoo?

Dermax can be used on an ongoing basis as a maintenance shampoo once symptoms are controlled, typically reducing to once-weekly use. However, if your symptoms do not improve after 4 weeks of regular use, or if they worsen at any point, you should stop and consult your GP or pharmacist. Long-term use without reassessment is not recommended if there is no clear benefit.

Does Dermax Therapeutic Shampoo treat scalp psoriasis?

Dermax is not specifically licensed for scalp psoriasis, which is a distinct inflammatory condition requiring different treatments — often including coal tar preparations or prescribed topical corticosteroids. If you suspect you have scalp psoriasis rather than dandruff or seborrhoeic dermatitis, it is important to get a proper diagnosis from your GP before starting any treatment. Self-treating psoriasis with an antiseptic shampoo alone is unlikely to be sufficient.

What are the latest findings on benzalkonium chloride for scalp conditions?

Benzalkonium chloride has a long-established safety and efficacy profile as a topical antiseptic, and its use in medicated shampoos for dandruff and seborrhoeic dermatitis is well-supported in clinical practice. Current evidence continues to support its role in reducing scalp microbial load and associated symptoms. For the most up-to-date clinical guidance, the NHS and BNF remain the most reliable UK sources.

How Should You Use Dermax Therapeutic Shampoo?

Using Dermax correctly makes a real difference to how well it works. Always apply it to a wet scalp and give it enough contact time before rinsing — rushing the process reduces its effectiveness.

What Is the Correct Dose of Dermax Therapeutic Shampoo?

There is no fixed measured dose for Dermax — you apply enough to cover the scalp adequately. The key variable is frequency of use, which should be guided by the severity of your condition and your response to treatment.

When Is the Best Time to Use Dermax Therapeutic Shampoo?

There is no strict time of day requirement for using Dermax — morning or evening use is equally effective. Many people find it easiest to incorporate into their regular shower or bath routine, which helps with consistency. What matters most is that you use it regularly on your chosen days each week, rather than sporadically.

If you use any other topical scalp products, apply Dermax first and allow it to rinse away completely before applying anything else. This avoids potential interactions and ensures the active ingredient has full contact with the scalp.

How Long Can You Use Dermax Therapeutic Shampoo For?

Dermax can be used for as long as symptoms persist, with frequency reduced to a maintenance level once the scalp is under control. If you have been using it twice weekly for four weeks without any noticeable improvement, it is worth speaking to your pharmacist or GP — your condition may need a different approach or a prescription-strength treatment.

There is no defined maximum duration of use, but ongoing use should be reassessed periodically. If symptoms return after stopping, you can resume use at the twice-weekly frequency. Always check the expiry date before each use.

Do not exceed the recommended dose. If in doubt, speak to your pharmacist.

Customer Reviews

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Anonymous

Having used this shampoo for 12 months prescribed by a consultant dermatologist I find it helps to sooth my itchy scalp and keeps the flakiness at bay

What Are the Most Common Side Effects of Dermax Therapeutic Shampoo?

Most people tolerate Dermax Therapeutic Shampoo well, and side effects are generally mild when they do occur. The most frequently reported effects are localised to the scalp and tend to resolve on their own without any specific treatment.

  • Mild scalp tingling or stinging during application
  • Temporary dryness of the scalp or hair shaft
  • Slight redness at the site of application
  • Mild itching immediately after use

What Are the Less Common Side Effects of Dermax Therapeutic Shampoo?

Less commonly, some individuals may experience a more pronounced reaction to benzalkonium chloride. These effects are not typical but are worth being aware of before you start using the product.

  • Allergic contact dermatitis — presenting as a rash, persistent itching, or localised swelling
  • A burning sensation that continues after rinsing
  • Changes in hair texture or increased dryness with prolonged use
  • Scalp peeling beyond the normal flaking associated with dandruff

What Are the Serious Side Effects of Dermax Therapeutic Shampoo?

Serious side effects are rare with topical benzalkonium chloride at the concentration found in Dermax. However, a small number of people may experience a significant allergic reaction, which requires prompt attention. Signs of a serious allergic reaction include swelling of the face, lips, tongue, or throat, difficulty breathing or swallowing, a widespread skin rash, or dizziness. If you experience any of these symptoms, stop using Dermax immediately and call 999 or go to your nearest A&E department.

What Should You Do If You Experience Side Effects of Dermax Therapeutic Shampoo?

For mild side effects such as temporary dryness or tingling, you may simply reduce the frequency of use and see whether symptoms settle. Ensure you are rinsing the shampoo away thoroughly, as residue left on the scalp can increase irritation. If side effects are moderate or persistent — particularly any sign of allergic contact dermatitis — discontinue use and speak to your pharmacist or GP before trying the product again. You can also report side effects directly to the MHRA via the Yellow Card scheme at yellowcard.mhra.gov.uk.

Can Dermax Therapeutic Shampoo Interact With Other Medicines?

No significant systemic drug interactions are currently documented for topical benzalkonium chloride at the concentration used in Dermax. However, using it alongside other medicated scalp products — such as corticosteroid scalp applications or other antiseptic shampoos — may increase the risk of local irritation or dryness. Always inform your pharmacist of any other scalp or skin treatments you are using so they can advise you appropriately. If you are taking oral medicines for a skin condition, check with your GP before adding any new topical product to your routine.

If you are concerned about any side effects, contact your pharmacist or GP immediately.

Patient Information Leaflet

Important - Before taking any medication, it is always important to read the Patient Information Leaflet (PIL)

Written and reviewed by our qualified team

GPhC Number: 2233073
Tarun Kumar

Reviewed by:

Tarun Kumar

Superintendent/ Clinical Lead

📖 Find out more about our team of medical content authors and how we ensure the accuracy of our content with our content guidelines.

Content last updated: 31 Mar 2025

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