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Derbac M Liquid

  • Clinically proven liquid treatment for head lice and eggs
  • Contains malathion 0.5% to kill lice effectively
  • Suitable for adults and children over 6 months
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In stock

£19.89
24 hr tracked delivery once approved
Fast & Free Delivery Options

Variety of delivery options including next day & free delivery.

100% UK-based Pharmacy

Pharmacy, clinic and prescribers based in Greater Manchester.

Free Online Consultations

Start your treatment with a quick and free online consultation.

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About Derbac M Liquid

Derbac M Liquid is a malathion 0.5% w/v cutaneous solution used for the treatment of head lice and their eggs (nits). It works by killing live lice and preventing further infestation when used correctly. This clinically proven head lice treatment is suitable for adults and children over 6 months of age.

Derbac M Liquid is applied directly to dry hair and scalp and left on for 12 hours to ensure effective treatment. A second application is usually required after 7 days if live lice are still present.

  • Derbac M Liquid – 150ml bottle
Medication Name Derbac M Liquid 0.5% w/v Cutaneous Solution
Active Ingredient Malathion 0.5% w/v
Other Ingredients methylhydroxybenzoate (E218), propylhydroxybenzoate (E216), emulsifying wax, potassium citrate, citric acid, perfume HT52 and water
Medication Form Topical cutaneous liquid for scalp and hair
Used to Treat Head lice and their eggs (nits)
Available Size 150ml bottle
Who Can Use It Adults and children over 6 months of age
Prescription Required? No – Pharmacy (P) medicine

What Is Derbac M Liquid Used For?

Derbac M Liquid is used for the effective treatment of head lice infestation in adults and children. It kills lice and helps eliminate their eggs when applied correctly and left on for the full recommended treatment time.

Who Is Derbac M Liquid Suitable For?

Derbac M is suitable for adults and children aged over 6 months.

Do not use Derbac M Liquid if you:

  • Are allergic to malathion or any of the ingredients
  • Are under 6 months of age

Speak to a healthcare professional before use if you:

  • Have broken, inflamed, or infected scalp skin
  • Are pregnant or breastfeeding
  • Have asthma (due to vapours)

How to Use Derbac M Liquid

  1. Apply to dry hair in a well-ventilated room.
  2. Ensure the scalp and entire length of hair are thoroughly covered.
  3. Allow hair to dry naturally and leave on for 12 hours (overnight).
  4. Wash hair with normal shampoo and rinse thoroughly.
  5. Use a fine-toothed comb to remove dead lice and eggs.
  6. Repeat treatment after 7 days if live lice are present.

Avoid contact with eyes and face. If accidental contact occurs, rinse immediately with plenty of water.

Possible Side Effects of Derbac M Liquid

Most people use Derbac M without problems. However, possible side effects include:

  • Scalp irritation
  • Redness or itching
  • Skin rash (rare)

Stop use and seek medical advice if severe skin reactions occur.

Warnings and Precautions

  • For external use only.
  • Keep away from naked flames, cigarettes, and heat sources (product is flammable).
  • Do not use near open fires or while smoking.
  • Avoid inhaling vapours.
  • Do not use on damaged or inflamed skin.

Storage Instructions

  • Store below 25°C.
  • Keep bottle tightly closed.
  • Keep out of sight and reach of children.

Derbac M Liquid Reviews

Our Experienced UK-based Pharmacy Team

Clinical Consultant
MUDr, MRCEM, EBCEM, FRCEM
GMC no. 7176414

Pharmacist
MPharm
GPhC no. 2065469

Pharmacist
MPharm
GPhC no. 2046514

Page content authored by Amjad Khan, last reviewed by Dr Hussain Ahmad on 6th March 2026.

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