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Hedrin 4% Head Lice Lotion 150ml

£12.99

Hedrin 4% Lotion 150ml – dimeticone head lice treatment for adults and children from 6 months. Kills lice and eggs in one 8-hour treatment.

  • Dimeticone 4% – works physically, so lice cannot become resistant
  • Kills head lice and their eggs
  • Leave on 8 hours or overnight, repeat after 7 days
  • Suitable from 6 months of age
  • Dispatched by a GPhC-registered UK pharmacy
SKU: 1016 Categories: , ,

Description

Hedrin 4% Lotion is a head lice treatment containing dimeticone 4% w/w. It is not an insecticide — it works physically, coating the lice in a silicone film that blocks their breathing and their ability to manage water, so they cannot survive and cannot develop resistance to it. Suitable from 6 months of age, and it kills both lice and eggs in one 8-hour treatment.

Why a physical treatment matters

Older head lice products worked as neurotoxins — chemical poisons that attacked the louse’s nervous system. Lice in the UK became widely resistant to them, which is the main reason parents find that a treatment they used a few years ago no longer works. Dimeticone is a silicone oil, not a poison: it works by smothering. There is no known mechanism for lice to become resistant to a physical mode of action, so it keeps working season after season.

How to use Hedrin 4% Lotion

  • Apply to dry hair — wet hair dilutes the lotion and stops it coating properly.
  • Work it evenly from the roots through to the tips, making sure the scalp is fully covered. Lice live close to the scalp, not at the ends.
  • Allow the hair to dry naturally. Do not use a hairdryer.
  • Leave on for at least 8 hours, or overnight.
  • Wash out with your normal shampoo.
  • Repeat the whole treatment 7 days later. This step is not optional — see below.

A 150ml bottle covers most head lengths for one application; very long or thick hair may need more, so buy enough for two full treatments per person from the outset.

The step most people skip — and why treatment fails

By far the commonest reason a head lice treatment “doesn’t work” is that the second application on day 7 never happened. Any eggs that survive or hatch after the first treatment will produce a new generation of lice within about a week, and the infestation looks like it came back. It didn’t — it was never fully cleared. Put the repeat date in your phone the moment you do the first one.

The second commonest reason is under-application: not enough lotion, not worked down to the scalp, or washed off early. Use enough to wet the hair thoroughly and give it the full 8 hours.

Do you need to treat the whole family?

Check everyone in the household on the same day using detection combing on wet, conditioned hair, and treat only those who have live lice. Treating people who don’t have them is unnecessary. Lice spread by prolonged head-to-head contact, not by hats, pillows or furniture, so there is no need to strip beds, bag toys or clean the house — that advice is a myth that costs parents a lot of wasted effort.

Safety and warnings

  • Suitable from 6 months. Under 6 months, use only under medical supervision.
  • Flammable: treated hair burns readily. Keep well away from naked flames, cigarettes, gas hobs and hair straighteners while the lotion is on the hair.
  • Avoid the eyes. If it gets in, rinse with plenty of water.
  • Stop using it if a rash or other sign of sensitivity develops.
  • Possible effects include scalp flaking, irritation and eye discomfort.

Lotion or lotion spray — which pack?

Both contain the same dimeticone 4%, use the same 8-hour contact time and the same day-7 repeat. The difference is application. This 150ml bottle pours, which suits shorter hair and lets you use plenty of product quickly. The 120ml Hedrin 4% Lotion Spray pumps directly onto the scalp, which many parents find easier on long or thick hair where getting down to the roots is the hard part. Also in our antiparasitic treatment range: Ovex for threadworm, the other classic school-age infestation.

Buy Hedrin online

Bury Healthcare Online is a GPhC-registered UK pharmacy (registration 1126145). Our pharmacy team can advise on detection combing, on treating during pregnancy or breastfeeding, and on what to do if lice are still there after a full two-application course.

Always read the instructions for use before applying. If live lice are still present after completing both applications, speak to your pharmacist.

Medically reviewed by Hassan Khan, MPharm, Independent Prescriber — Superintendent Pharmacist, Bury Healthcare Online (GPhC-registered pharmacy 1126145). Last reviewed: July 2026.

Hedrin FAQs

Does Hedrin kill eggs as well as lice?
Yes. Hedrin 4% Lotion works over the 8-hour contact period to kill head lice and their eggs. The repeat application seven days later is still needed, because it catches any eggs that survived the first treatment and have since hatched.
How long do you leave Hedrin on the hair?
At least 8 hours, or overnight. Apply it to dry hair, let the hair dry naturally without a hairdryer, then wash out with normal shampoo. Rinsing it off early is one of the main reasons treatment fails.
Do I really need to do a second Hedrin treatment after 7 days?
Yes – and skipping it is the single commonest reason head lice appear to come back. Any eggs that make it through the first treatment hatch within about a week, so the day-7 repeat is what actually clears the infestation. Put the date in your phone when you do the first application.
Can head lice become resistant to Hedrin?
There is no known mechanism for resistance. Dimeticone is a silicone that works physically, by coating the lice and blocking their breathing and water balance, rather than poisoning their nervous system the way older insecticide treatments did. Resistance to those older chemical treatments is why they often no longer work.
What age can Hedrin be used from?
From 6 months of age. For babies under 6 months it should only be used under medical supervision – speak to your pharmacist or health visitor.
Is Hedrin safe in pregnancy or while breastfeeding?
Dimeticone is not absorbed into the body in any meaningful amount, which is why it is generally considered suitable. Check with your pharmacist before use so you get advice for your particular circumstances.
Do I need to treat the whole family?
Check everyone on the same day by detection combing wet, conditioned hair, then treat only the people who actually have live lice. Treating people without lice serves no purpose.
Do I need to wash bedding, hats and soft toys?
No. Head lice spread by prolonged head-to-head contact and cannot survive long away from a scalp. Stripping beds, bagging toys and deep-cleaning the house is wasted effort – the widely repeated advice to do so is a myth.
Is Hedrin flammable?
Treated hair burns readily while the lotion is on it. Keep well away from naked flames, cigarettes, gas hobs, hair straighteners and hairdryers until it has been washed out.
What if there are still lice after both treatments?
First check you are seeing live, moving lice rather than empty egg cases still stuck to the hair – old cases stay attached as the hair grows and are not a sign of active infestation. If there are genuinely live lice after a completed two-application course, speak to your pharmacist about switching to a different product or wet-combing.

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