Medication

Permethrin

The standard cream for scabies. It kills the mites overnight, but it only works if everyone in the household is treated on the same night, and the itching carries on for weeks after the mites are dead.
Dr. Schwarz, MD · Board-certified dermatologistLast reviewed September 8, 2026
16:9 hero for Permethrin. Never cropped: the tone strip and the corner logo depend on the full frame.

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Everyone in the house gets treated the same night, rash or no rash, and the itch keeps going for two to four weeks after the mites die because your immune system is still reacting to what they left behind. That is not failure and does not need another round. Most failures I see are application failures — under the nails, between the fingers and toes, the navel, groin, behind the ears, the soles. I give a second application about a week later, because permethrin is reliable against mites and less reliable against eggs.

— Dr. Schwarz, Board Certified Dermatologist

Key Facts

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Also calledElimite, Lyclear, Nix
Drug classTopical pyrethroid scabicide
Applied as5% cream for scabies, 1% cream rinse for head lice
Typical courseOne overnight application, repeated about a week later
Time to workMites die within hours. Itching settles over two to four weeks
Prescription onlyYes for the 5% cream in the United States. The 1% lice rinse is sold over the counter

What It Is

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Permethrin is a man-made version of pyrethrin, an insecticide from chrysanthemum flowers. The 5% cream has been the first-choice scabies treatment in most national guidelines for decades, approved for adults and infants from two months. Scabies is an infestation with a mite that burrows into the top layer of skin, spread by prolonged skin-to-skin contact — which is why it moves through households, care homes and shared accommodation. The rash and the intense night-time itch are an allergic reaction to the mite, not damage from the burrowing. A separate 1% permethrin rinse is sold for head lice. Weaker, different problem, not a scabies treatment.

How It Works

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Permethrin acts on sodium channels in the mite's nerve cells and holds them open, so the nerve cannot reset between signals. The mite is paralyzed and dies. It kills adult mites reliably and their eggs less reliably, which is why a second application is given about a week later.

Human and animal cells break permethrin down quickly, and very little passes through intact skin. That gap is the whole safety margin, and it is why a cream applied to the entire body is reasonable.

The itch confuses people. It is an allergic reaction to mite proteins and droppings left in the skin, not a sign of living mites. Those take weeks to clear, so itching usually continues, and can get slightly worse, after successful treatment.

Here is where Permethrin acts in the skin, and what the others do instead.

About Permethrin
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Skin basics
BARRIEREPIDERMISDERMISPOREOILGLANDKILLS MITESCROSSES EASILYSTOPS PLUGS FORMINGUNCLOGS THE POREKILLS BACTERIAKILLS YEASTLOWERS OIL PRODUCTION

Everyone carries these mites in their follicles. In some people the immune system reacts to them, and reducing their number reduces the bumps and the redness that come with them. For scabies and lice. Neck down, overnight, repeated in a week.

Permethrin crosses into the outer layers where the mites are and stays there. Almost none reaches the blood, which is why it is used on infants.

Retinoids change how the lining of the pore sheds its cells, so the plug that starts a spot stops forming in the first place. That is why they prevent spots rather than treat the ones already there, and why the first weeks can look worse before they look better.

Salicylic acid dissolves in oil, so it gets down inside the pore rather than sitting on the surface, and loosens the plug of dead skin and sebum blocking the way out.

This works on the bacteria growing in an inflamed pore. Less bacteria means less for the immune system to react to, which is what takes the redness and soreness out of a spot.

The yeast involved here lives on everyone's skin and only causes trouble when it overgrows in oil. This reduces it, which is why the flaking and itching settle and why it comes back if treatment stops for good.

This works upstream of the spot, on the gland itself. Less oil means fewer plugs, less for bacteria to feed on and less inflammation, which is why it changes the pattern rather than clearing one spot.

The outer film of dead cells and oil. It holds water in and keeps irritants out, and it is thinner than a sheet of paper. Almost every dry, itchy, stinging skin problem starts here.

The outer layer, and the only one anything in a jar reaches. It renews itself constantly: a cell made at the bottom takes about a month to reach the surface and flake off. Most of what a skincare product does, it does here.

The living layer underneath, holding the blood vessels, the nerves and the collagen. It is where lasting change happens and it is hard to reach: most of what is sold for the skin never gets this far.

What It Treats

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Head Lice
Moderate evidence
The usual first treatment, applied to dry hair, left the stated time and rinsed, then repeated in seven to ten days because it does not reliably kill eggs. Where lice are not resistant it works well. Resistance to it is now common in many areas, so if two proper courses fail, the answer is a different medicine, not a third round.

Not the Best For

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The itch, straight away
Doesn't work
The mites die within hours, but the itch is a reaction to them and settles over two to four weeks. Repeating the treatment for itch alone does not speed that up.
Lice that survive two correct treatments
Doesn't work
Head lice resistant to permethrin are widespread. When two properly applied courses fail, a different treatment is used rather than a third round of the same one.

Forms

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5% cream:

1% cream rinse:

Sprays and pet products:

Strengths

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Two strengths, made for two different problems rather than a ladder to climb.

WeakestStrongest
1%5%
The lice strength
1%
An over-the-counter cream rinse for head lice. Too weak for scabies.
The scabies strength
5%
The only strength used for scabies and the highest made. If it fails there is nothing stronger in the family, so the next step is a different drug.

Basics

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When to Apply
At bedtime, on cool dry skin. Adults and older children apply from the jaw line down and cover everything — between fingers and toes, under the nails, wrists, armpits, waistband, navel, groin, buttock crease, soles. In babies, young children and anyone with a weakened immune system, treat the scalp, face, ears and hairline too. Wash off after eight to fourteen hours, usually the next morning.
How to Start
Everyone in the household and every recent close contact is treated on the same night, itching or not. A person can carry mites for weeks before a rash appears, and one untreated contact reinfects the house. The same day, wash bedding, towels and clothes from the last three days on a hot wash and dry hot, or bag them for three days.
If It Irritates
Mild stinging, burning or a burst of extra itching in the first day or two is expected. A plain moisturizer after rinsing helps. Stop and ask if you get spreading redness, swelling or blistering — that points to allergy, not the usual sting.
If It’s Not Working
The second full application a week after the first is standard, not failure. Itching alone is not failure either. New burrows, new spots four weeks after treatment, or itching clearly getting worse rather than slowly better need another look.

Sample Routine

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Here is where Permethrin sits in a day, and what goes around it. Pick what you are treating and what your skin is like, and the rest of the routine changes to suit.

What to Expect

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Night 1 | Treating
Applied head to toe and left on overnight. Stinging or extra itching for a few hours is common. The mites die within hours, and you will not feel it happen.
Days 1 to 7 | Still itching
The rash and itch stay the same or get slightly worse — the immune reaction to dead mites, not live ones.
Week 1 | Second application
The repeat dose, about seven days after the first.
Weeks 2 to 4 | Settling
The itch fades gradually. Most are comfortable by four weeks, occasionally six.
After 4 weeks | Judge it here
No new burrows and no new spots four weeks after the last application is the sign it worked.

What to Avoid

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  • A hot bath or shower right before applying It opens the skin's blood vessels, increasing absorption and the sting. Cool dry skin is the right surface.
  • Washing your hands during the treatment If you wash them, put the cream back on. Hands are the most commonly missed and reinfested area.
  • Treating only the person who itches The most common reason scabies comes back.
  • Repeating it because you still itch Extra applications irritate the skin and cause a rash of their own, which gets mistaken for more scabies.
  • Strong steroid creams before diagnosis They calm the rash enough to hide the burrows, making scabies much harder to identify.
  • Fumigating the house or spraying furniture The mite does not survive long off a person. Washing bedding and recent clothing is enough.

Monitoring

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No blood tests or laboratory monitoring for ordinary use.

Monitoring is a look at the skin four weeks after the last application. The question is whether there are new burrows or new spots, not whether you still itch — persistent itching is expected.

Crusted scabies, sometimes called Norwegian scabies, is different — an enormous mite count, thick scale rather than scattered spots, mostly in people who are elderly, immunosuppressed or unable to feel the itch. It spreads easily and needs specialist care: repeated applications, usually an oral medicine, close follow-up.

If You Stop

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There is nothing to taper and no rebound. Permethrin is a short course that ends after the second application. Itching afterwards is treated in its own right — a moisturizer, an antihistamine at night, or a mild steroid cream. That treats the immune reaction, not the mites. The itch commonly takes two to four weeks and sometimes up to six to settle. The other reason it comes back is reinfestation — almost always someone in the household or close circle who was not treated.

Cost

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Generic 5% permethrin cream is inexpensive, widely stocked, and on the World Health Organization list of essential medicines. Cost is rarely the barrier. The branded version costs more for nothing extra. Where cost adds up is treating the household. Four or five people on the same night means several tubes at once, and some plans cover only one tube per prescription. Tell the prescriber how many people are being treated so the quantity is written for the household rather than the patient.

Ask Your Doctor

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If you are pregnant or breastfeeding
Permethrin is the usual choice in pregnancy, but ask the doctor managing your pregnancy before you apply it.
If you are treating a young baby
Not approved below two months old, and the areas treated in infants differ. This needs a doctor.
If you have eczema or broken skin
More is absorbed through skin that is not intact, and it stings sharply on raw skin.
If you have reacted to chrysanthemums
Ragweed or an insect repellent counts too. Permethrin allergy is uncommon but reported, so say so first.
If you have new spots or burrows
Four weeks after treatment, that is the finding that needs review, not the itch.
If the skin is thickly scaled and crusted
Rather than scattered and itchy. Crusted scabies carries a very high mite count, spreads easily and usually needs an oral medicine too.
If you take an immune-suppressing medicine
Infestations are heavier, harder to clear and need closer follow-up.

How It Compares

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Oral ivermectin
Different job
The usual alternative when a cream is impractical, such as in outbreaks, in crusted scabies, or for someone who cannot apply cream everywhere. Taken as two doses about a week apart. Avoided in pregnancy and in very small children.
Benzyl benzoate lotion
Worse
Long-standing evidence and very cheap, used widely outside the United States. It stings considerably more, which is the usual reason permethrin is chosen where both are available.
Sulfur ointment
Worse
The oldest option, with weaker formal evidence but a long safety record. It is greasy, smells strongly and needs three nights in a row. It is the fallback in very young infants and sometimes in pregnancy.
Crotamiton
Different job
Weaker evidence for killing the mites and lower cure rates. Its useful role is easing the itch rather than clearing the infestation.
Malathion lotion
Different job
Effective, and used mainly where permethrin resistance is a local concern. Flammable and strong-smelling.
Permethrin's case
Different job
It is the usual first choice because it is effective in one or two applications, cheap and generally well tolerated, not because the others do not work.

Myths

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  • "Scabies means you are dirty." Nothing to do with hygiene. It spreads by prolonged skin contact, through households and care homes however clean.
  • "If I still itch, the treatment failed." Itching normally continues for two to four weeks — the reaction to dead mites and droppings takes that long to settle.
  • "You can catch it from a bus seat." The mite survives only a couple of days off a person and travels poorly. Spread is by prolonged skin-to-skin contact, less often shared bedding.
  • "Only the person with the rash needs treating." Contacts carry mites for weeks with no symptoms, and they are the usual reason it returns.
  • "You need to fumigate the house." Washing bedding, towels and recent clothing is enough. No sprays or foggers.
  • "The lice product will do." The 1% lice rinse is a different strength for a different problem.

Questions Patients Ask

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Why do I still itch two weeks later?

The itch is an allergic reaction to mite proteins and droppings left in the skin, not to living mites. It takes two to four weeks, sometimes six, to settle. Not failure.

Does everyone in the house really need treating?

Yes. Someone can carry mites for four to six weeks before they itch, and an untreated contact reinfects everybody else.

Do I need a second application?

Yes, a full one about a week later. Permethrin kills mites reliably and eggs less reliably, so the repeat catches anything that hatched.

Do I have to treat my face and scalp?

Adults and older children treat from the jaw line down. Babies, young children and anyone with a weakened immune system have the scalp, face and ears treated too — mites are found there.

What do I do about bedding and clothes?

Wash anything used in the last three days hot and dry it hot, or seal it in a bag for three days. No need to spray furniture or fumigate.

Can I use it in pregnancy?

Permethrin is the usual choice when scabies has to be treated in pregnancy, but ask the doctor managing your pregnancy first.

References

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