Derbac-M Liquid
From £20.99
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Our friendly team is available to help Monday to Friday 9:00am – 5:00pm.
If you need urgent assistance, do not use this service. Call 111, or in an emergency call 999.
Head lice are tiny insects that live in hair and are especially common in school-age children. They are not a sign of poor hygiene, and they are easy to treat. Complete a short online consultation and, if suitable, our UK pharmacy team can send you Derbac-M Liquid, an alcohol-free head lice treatment for adults and children aged 6 months and over.
Head lice are common, especially in children aged 4 to 11 and the families they live with. Here is what you need to know before you treat.
Head lice are small, wingless insects, about the size of a sesame seed when fully grown, that live on the scalp and feed on tiny amounts of blood. They lay eggs that are glued to the hair close to the scalp, and the empty white egg cases left behind after hatching are called nits. Head lice cannot jump, fly or swim. They spread through direct head-to-head contact, which is why they pass so easily between children at school and among family members.
An itchy scalp is the most common sign, although many people have no symptoms at all. The only way to be sure is to find a live louse using a fine-toothed detection comb. If you find one, check everyone in your household and treat anyone with live lice on the same day. There is no need to keep children off school, and you do not need to wash bedding or clothes on a hot wash.
Derbac-M Liquid contains 0.5% malathion, which kills both head lice and their eggs. It is alcohol-free, so it is often a better choice for people with asthma or eczema and for young children. Use it alongside wet combing to remove dead lice and eggs, and to check the treatment has worked.
| Option | Best for | How it works | Things to know |
|---|---|---|---|
| Derbac-M Liquid (0.5% malathion) | Confirmed live head lice in adults and children aged 6 months and over | An insecticide that kills lice and their eggs. Applied to dry hair, left for 12 hours, then washed out | Alcohol-free. Repeat after 7 days. Do not use more than once a week or for more than 3 weeks in a row |
| Wet combing with a detection comb | Babies under 6 months, pregnancy, or anyone who prefers a medicine-free option | Physically removes lice from wet, conditioned hair using a fine-toothed comb | Comb on days 1, 5, 9 and 13, then check on day 17. Also useful after Derbac-M to remove dead lice and eggs |
Not sure if Derbac-M is right for you or your child?
Most cases of head lice can be treated at home. Speak to a pharmacist or GP, or call NHS 111, if any of the following apply.
Find out more about checking for head lice, wet combing and stopping them coming back.
How to check for head lice, a step-by-step guide to wet combing, and when to speak to a pharmacist.
Read guidePractical, clinician-reviewed articles on common family health problems, from skin and scalp conditions to everyday infections.
Read guideAnswers to the questions parents and families ask us most about head lice, nits and using Derbac-M. If your question isn't covered here, our pharmacy team can help during your consultation.
Derbac-M Liquid is a pharmacy medicine containing 0.5% malathion, an insecticide that kills head lice and their eggs. It is also licensed for scabies and pubic lice, although this page focuses on head lice. Derbac-M is a water-based, alcohol-free liquid, which makes it a good option for people with asthma or eczema and for young children. It can be used by adults and children aged 6 months and over. Before we supply it, you complete a short online consultation that our pharmacy team reviews to make sure it is suitable.
Apply enough liquid to dry hair to cover the whole scalp, working it through from the roots to the tips. Let the hair dry naturally in a warm, well-ventilated room. Leave it on for 12 hours, or overnight, then shampoo, rinse and comb through with a fine-toothed nit comb to remove dead lice and eggs. Repeat the treatment 7 days later to kill any lice that have hatched since. Do not use Derbac-M more than once a week, or for more than 3 weeks in a row. Always read the patient information leaflet that comes with your pack.
An itchy scalp is a common sign, but many people with head lice have no symptoms at all. The only way to be sure is to find a live louse. Use a fine-toothed detection comb on wet or dry hair, combing from the scalp to the ends in sections and checking the comb after each stroke. Finding nits (empty white egg cases) on their own does not always mean there is an active infestation, so only treat when you find a live louse.
If one person has head lice, check everyone else in the household with a detection comb. Only treat the people who have live lice, but treat them all on the same day so the lice cannot pass back and forth. Using a treatment 'just in case' on people without lice is not recommended. Our pharmacy team will ask about this during your consultation.
No. NHS advice is that there is no need to keep children off school or nursery because of head lice. Head lice cannot survive for long away from the scalp, so you do not need to wash bedding, clothes or towels on a hot wash or use special cleaning products. Washing combs and brushes in hot water after use is a sensible extra step.
First, check the treatment was used correctly: enough liquid to cover the whole scalp, left on for the full 12 hours, and repeated after 7 days. Lice found after treatment may also be a new infestation picked up from someone else. If you still find live lice after two full courses used correctly, the lice may be resistant to malathion. Speak to a pharmacist or GP about other options, such as a treatment that works in a different way or regular wet combing.
If you are pregnant, trying to get pregnant or breastfeeding, speak to a pharmacist or GP before using Derbac-M. Wet combing is often recommended first in pregnancy because it does not involve any medicine. If Derbac-M is advised while you are breastfeeding, avoid applying it near the breast area and wash your hands thoroughly afterwards. Our pharmacy team will go through this with you during your consultation.
Helpful reads related to this treatment area.
Head lice are common and easy to treat with the right product and a little patience. Complete a short online consultation and, if Derbac-M is suitable, our pharmacy team will send it to you in discreet packaging.