Ivermectin for Scabies: Dose by Weight, Second Dose Timing and How It Compares With Permethrin

Oral ivermectin is the only tablet in CDC's scabies treatment guidance. For ordinary (classic) scabies the usual dose is about 200 micrograms per kilogram of body weight, taken as two doses 7 to 14 days apart. For crusted scabies it is given on several days together with a cream. In the US it is used off label for scabies, because the FDA approved it only for two worm infections. Permethrin 5% cream is still the first-choice treatment for young children and during pregnancy.

This guide covers the dose by weight, why a second dose is needed and when to take it, the food question (the US label and the scabies guidelines disagree), how the tablet compares with permethrin in trials, the crusted scabies schedule, who should not take it, and what a course costs. We sell ivermectin tablets and permethrin cream, so we have a commercial interest. Every number below comes from the labels, CDC guidance, trials or price data listed under Sources. This is general information, not a prescription: your dose should come from a clinician who has confirmed the diagnosis and knows your weight and other medicines.

The short answer

For classic scabies, CDC guidance gives oral ivermectin at 200 mcg/kg per dose, with a second dose 7 to 14 days later (the 2021 STI treatment guidelines say "repeated in 14 days"). CDC advises taking it with food for scabies because food raises absorption. The US Stromectol label, which was written for worm infections, says to take it on an empty stomach. Ivermectin has limited effect on scabies eggs, which is why one dose is not enough. Everyone in the household and close contacts should be treated at the same time, and bedding and clothing used in the 3 days before treatment should be washed hot. Itching often lasts for weeks after the mites are dead. That is not, by itself, a sign that treatment failed.

Is ivermectin approved for scabies?

It depends on the country. In the US, the Stromectol label lists only strongyloidiasis of the intestinal tract and onchocerciasis, and the CDC states plainly that "oral ivermectin is not FDA approved for the treatment of scabies." Doctors still prescribe it off label, and CDC includes it in its scabies treatment guidance. Permethrin 5% cream is FDA approved for scabies, as are spinosad 0.9% and, for adults, crotamiton 10%.

Country	Oral ivermectin for scabies	What the official document says
United States	Off label	Stromectol label: strongyloidiasis and onchocerciasis only. CDC: not FDA approved for scabies.
Australia	Approved, with conditions	TGA Stromectol PI: crusted scabies with topical therapy, and scabies when prior topical treatment has failed or is contraindicated.
France	Approved	ANSM Stromectol 3 mg summary: treatment of human sarcoptic scabies, 200 mcg/kg as a single dose.

The practical point for US readers: you will need a prescription, and your prescriber is choosing an off-label use that CDC supports. If you are comparing buying routes, our guide to ivermectin for sale in the USA covers the legal side. Never use veterinary ivermectin: our page on ivermectin horse paste explains why the doses and ingredients are not made for people.

How the dose is worked out

Ivermectin for scabies is dosed by body weight at about 200 micrograms (0.2 mg) per kilogram per dose. The tablets usually come as 3 mg, so the dose is rounded to whole tablets using weight bands. The bands below come from the US Stromectol label (Table 1, written for strongyloidiasis at the same 200 mcg/kg) and match the Australian Stromectol PI, which uses them for scabies.

Body weight	Dose per treatment day	Number of 3 mg tablets
Under 15 kg	Not established	Use permethrin instead (see below)
15 to 24 kg	3 mg	1
25 to 35 kg	6 mg	2
36 to 50 kg	9 mg	3
51 to 65 kg	12 mg	4
66 to 79 kg	15 mg	5
80 kg or more	About 200 mcg/kg	Calculated by weight (for example 16 mg at 80 kg, 20 mg at 100 kg)

Tablet strength matters for accuracy. With 3 mg or 6 mg tablets the dose can follow the bands closely. A single 12 mg tablet suits someone of about 51 to 65 kg, but it cannot be split into 3 mg steps, so people outside that band usually need a combination of strengths. Do not guess. Ask the prescriber to write the dose in milligrams and the number of tablets of the strength you have.

Why one dose is not enough

The scabies mite lives its whole life on human skin. According to the CDC's parasite biology page, a female lays 2 to 3 eggs a day in her burrow, the eggs hatch in 3 to 4 days, and the larval stage lasts another 3 to 4 days before the mites moult and mature. She keeps laying eggs for the rest of her life, which is 1 to 2 months.

The 2021 CDC STI treatment guidelines state that "oral ivermectin has limited ovicidal activity; a second dose is required for eradication." In other words, the first dose kills mites that are already hatched, but eggs in the skin survive. The second dose is timed to catch the mites that hatch from those eggs before they are old enough to lay eggs of their own.

When to take the second dose

The guidance varies slightly by source, but all of it lands in the same window of about one to two weeks.

Source	Second dose
CDC clinical care page for clinicians	Two doses of 200 mcg/kg, each 7 to 14 days apart
CDC STI Treatment Guidelines 2021	200 mcg/kg, repeated in 14 days
Australian Stromectol PI	One dose on day 1 and another between day 8 and day 15
French Stromectol summary (ANSM)	Single dose; second dose within 8 to 15 days for profuse or crusted scabies, or at 2 weeks only if new specific lesions appear or a skin scraping is positive

The Cochrane review found one trial (80 people) that compared one dose with two. The review's illustrative cure rates were 87% with one dose and 90% with two, a risk ratio of 0.97 (95% CI 0.83 to 1.14, rated high certainty), so that trial did not show a difference. US guidance still recommends two doses because of the egg problem, and that is the schedule most prescribers will give you.

With food or on an empty stomach?

This is where the sources disagree, and it is worth understanding why.

• The US Stromectol label says tablets should be taken "on an empty stomach with water." The French summary also says to take it fasting, with no food for 2 hours before or after.
• The same US label reports that taking 30 mg after a high-fat meal gave "an approximate 2.5-fold increase in bioavailability" compared with taking it fasting.
• For scabies, the CDC STI guidelines say "ivermectin should be taken with food because bioavailability is increased," and the CDC clinical care page notes that scabies experts recommend a meal for the same reason.

The label gives no scabies-specific reasoning because scabies is not one of its approved uses. The CDC's case for food is simply that it increases how much drug is absorbed. Because the official documents differ, follow the instruction your prescriber gives you. If they have not said, ask. Do not double the dose to make up for an empty stomach.

How ivermectin compares with permethrin cream

The best summary of head-to-head trials is a 2018 Cochrane review of 15 studies with 1,896 participants, most of them done in South Asia and North Africa. Comparing oral ivermectin 200 mcg/kg with permethrin 5% cream:

Time point	Risk ratio for clearance (ivermectin vs permethrin)	95% CI	Trials (people)	Certainty
1 week	0.65	0.54 to 0.78	6 (613)	Low
2 weeks	0.91	0.76 to 1.08	5 (459)	Low
4 weeks	0.92	0.82 to 1.03	5 (581)	Low

A risk ratio below 1 means fewer people cleared on ivermectin. At one week permethrin was clearly ahead. By two and four weeks the difference was small and not statistically significant. The review's own conclusion was that "for the most part, there was no difference detected in the efficacy of permethrin compared to systemic or topical ivermectin," while noting that confidence in the estimates was "mostly low to moderate" and that poor reporting was a major limitation. The CDC reaches the same practical view: the two treatments have "similar efficacy for cure of scabies."

So the choice usually comes down to practical factors rather than which works better:

• Tablets are easier for people who cannot apply cream to the whole body properly, such as older adults, people with limited mobility, or people in care homes.
• Tablets avoid the problem of missed skin areas, which is a common reason cream fails.
• Permethrin is preferred for children under 15 kg and during pregnancy and breastfeeding (CDC), although its own label advises considering a temporary pause in nursing.
• Permethrin is the only one of the two that is FDA approved for scabies.

What happens when a whole community takes ivermectin

The strongest evidence for ivermectin against scabies comes from mass treatment, where a whole population is treated at once. In the SHIFT trial in Fiji (published in the New England Journal of Medicine in 2015), three island communities with very high scabies rates were each given a different approach.

Approach	People	Prevalence at start	At 12 months	Relative fall
Standard care	803	36.6%	18.8%	49%
Permethrin for everyone	532	41.7%	15.8%	62%
Ivermectin for everyone	716	32.1%	1.9%	94%

Impetigo, a skin infection that often follows scabies scratching, also fell most in the ivermectin community (24.6% to 8.0%, a 67% fall). Adverse events were mild but more common with ivermectin than with permethrin (15.6% vs 6.8%). The trial compared whole communities, not individuals, so it does not prove one dose of ivermectin beats one tube of cream for a single person. What it shows is that a tablet everyone actually takes can work better at population level than a cream people may apply unevenly.

Treat everyone at the same time

Scabies spreads by prolonged skin-to-skin contact, and the CDC notes that a person can pass it on before they have any symptoms. A first infestation can take 4 to 8 weeks to cause itching. This is why treating only the person who itches so often fails: an untreated partner or child reinfects them.

The CDC's general advice is to "treat all household members and close contacts at the same time as the person with scabies." The 2021 CDC STI guidelines add that people who have had sexual, close personal or household contact with the patient in the month before the infestation should be examined, and those found to be infested should be treated. Each person gets ivermectin or permethrin as suits their age and situation.

Bedding, clothing and the home

Mites do not live long off the body. According to the CDC, they generally do not survive more than two to three days away from human skin, and temperatures above 50°C (122°F) for 10 minutes kill mites and eggs. CDC advice for classic scabies:

• Machine wash bedding, towels and clothing used in the 3 days before treatment in hot water, and dry on a hot cycle, or dry clean them.
• Items that cannot be washed can be sealed in a plastic bag for several days to a week (the STI guidelines say kept away from body contact for more than 72 hours).

The CDC says children and adults can usually return to school, childcare or work the day after treatment.

Crusted scabies needs a different plan

Crusted (Norwegian) scabies is a severe form in which the skin carries very large numbers of mites. It is very contagious and is not something to treat at home with a standard two-dose course.

The 2021 CDC STI guidelines recommend combination treatment: a topical scabicide (5% permethrin cream applied to the whole body daily for 7 days, then twice a week until cure, or 25% benzyl benzoate) together with oral ivermectin 200 mcg/kg on days 1, 2, 8, 9 and 15. Severe cases might need further doses on days 22 and 29. The CDC clinical care page adds that there is no consensus on the best ivermectin schedule, and lists 3-, 5- and 7-dose options that experts use. A keratolytic cream to soften the crusts may also be used. In Australia, crusted scabies is one of the approved uses of Stromectol, and the PI notes that moderate to severe cases may need more than 3 doses. Our Australian ivermectin buying guide explains when Stromectol is listed on the PBS and what a script costs.

What to expect after treatment

The mites die within days, but the itching often does not stop right away. The allergic reaction to mite proteins and debris left in the skin keeps going for a while. CDC states that "itching may continue for several weeks after treatment even if all the mites and eggs are killed." The permethrin label reports a similar pattern: about 75% of people who were still itching at 2 weeks had stopped by 4 weeks.

Signs that need a check rather than more waiting:

• New burrows (thin wavy lines, often between the fingers or on the wrists) after both doses
• Itching that is getting worse rather than slowly settling after 2 to 4 weeks
• Pus, crusting or spreading redness, which can mean a bacterial skin infection

The CDC STI guidelines say retreatment 2 weeks after the first regimen can be considered for people who still have symptoms or live mites. Persistent itch alone is not a reason to repeat treatment, according to the permethrin label.

Side effects at scabies doses

At 200 mcg/kg, ivermectin is usually well tolerated. In the Cochrane review, adverse events at 4 weeks were estimated at 5% of people on ivermectin and 4% on permethrin (risk ratio 1.30, 95% CI 0.35 to 4.83, low certainty), and nobody stopped treatment because of side effects in either group. In the US label's strongyloidiasis trials (109 patients given one or two doses of 170 to 200 mcg/kg), the most frequent drug-related reactions were dizziness and itching (2.8% each), followed by nausea and diarrhoea (1.8% each). For the full label tables and how rates differ by condition, see our guide to ivermectin side effects.

The US label also carries warnings that matter even at normal doses:

• Nervous system effects. Neurotoxicity, including drowsiness, confusion, disorientation, stupor, coma and death, has been reported. Stop and get medical help for any of these.
• Loa loa. People heavily infected with the Loa loa worm (found in parts of Central and West Africa) can develop serious or fatal encephalopathy. Anyone who has lived in those areas should tell the prescriber.
• Warfarin. Rare increases in INR have been reported when ivermectin was taken with warfarin.
• Allergy. The only absolute contraindication on the US label is hypersensitivity to any ingredient.

Who should not take ivermectin for scabies

Group	What the sources say	Usual alternative
Children under 15 kg	US label: safety and effectiveness not established under 15 kg. CDC: infants and young children should be treated with permethrin. Australian PI: not for children under 15 kg and under 5 years.	Permethrin 5% cream (label: from 2 months of age)
Pregnancy	US label: should not be used in pregnancy because safety has not been established. CDC STI 2021: likely low risk, but permethrin is preferred because data are limited.	Permethrin 5% cream
Breastfeeding	US label: excreted in breast milk in low concentrations; treatment of mothers who intend to breastfeed "should only be undertaken when the risk of delayed treatment to the mother outweighs the possible risk to the newborn." CDC: likely compatible, but permethrin preferred.	Permethrin 5% cream (its label advises considering a temporary pause in nursing, because of animal tumour findings)
Allergy to ivermectin	Contraindicated (US label)	Permethrin, or another topical agent

On pregnancy, the evidence is thin rather than alarming. A 2020 systematic review in Lancet Global Health pooled 893 women with 899 pregnancy outcomes, most exposed by accident during mass treatment campaigns. It found no statistically significant rise in miscarriage, stillbirth or birth defects, but the certainty was very low and the authors concluded there was insufficient evidence to call it safe. That is why permethrin remains the choice in pregnancy.

Permethrin cream: how it is used

Because it is the main alternative, it helps to know what correct permethrin use looks like. According to the Elimite (permethrin 5% cream) label:

• Massage the cream into the skin from the head to the soles of the feet.
• About 30 g is enough for an average adult.
• Wash it off after 8 to 14 hours.
• One application is generally curative. Living mites after 14 days mean retreatment is needed. The CDC notes that two applications about a week apart may be necessary.
• Burning or stinging occurred in 10% of patients and itching in 7%.

The CDC STI guidelines describe applying permethrin from the neck down. Cream works only where it is applied, so missed areas such as between the toes, under the nails and in skin folds are a common cause of failure.

What a course costs

US pharmacy acquisition costs come from the Medicaid NADAC file. These are what pharmacies pay wholesalers, not the shelf price you pay, which adds dispensing fees and margin and depends on insurance or coupons. As of 21 October 2026, the median NADAC was $2.02811 per generic ivermectin 3 mg tablet and $0.23052 per gram of generic permethrin 5% cream.

Course	Amount	NADAC cost
Permethrin, 1 adult application	30 g	$6.92
Permethrin, 2 applications	60 g	$13.83
Ivermectin, 1 dose for 66 to 79 kg	5 × 3 mg tablets	$10.14
Ivermectin, 2 doses for 66 to 79 kg	10 × 3 mg tablets	$20.28

Per person, both are inexpensive at acquisition cost. The difference grows with household size and body weight: a family of four being treated together needs a tablet count or cream amount for each person.

Common mistakes that cause treatment to fail

• Skipping the second ivermectin dose because the itch improved
• Treating one person but not partners, children or others in the household
• Taking the dose meant for a lighter person, or splitting a 12 mg tablet into uneven pieces
• Not washing bedding and clothes from the 3 days before treatment
• Treating crusted scabies with a standard two-dose course
• Re-treating repeatedly for itch that is really the normal post-treatment reaction
• Using veterinary ivermectin products, which are not dosed or formulated for people

Questions to ask your prescriber

• What is my dose in milligrams, and how many tablets of my strength is that?
• Should I take it with a meal or on an empty stomach?
• On which day exactly should I take the second dose?
• Who else in my home needs treatment, and with what?
• Do any of my other medicines, such as warfarin, need checking?
• When should I come back if the itching does not settle?

For general ivermectin dosing in other infections, see our ivermectin dosage guide. For the brand and its US generics, see Stromectol vs generic ivermectin. For how quickly the drug acts in worm infections, see how long ivermectin takes to kill parasites. Ivermectin cream is a different product used for rosacea, covered in our ivermectin cream guide.

Where SafeRxPills fits

We sell Indian-made ivermectin tablets in several strengths, which allows weight-based dosing: Ivercor 3 mg, Ivercor 6 mg, Ivecop 6 mg, Ivercor 12 mg and Ivecop 12 mg. We also sell permethrin cream (Permin Cream 30 g and Permite Cream 60 g). These are Indian-market products, not FDA-approved Stromectol or Elimite. Prices per pack and US delivery times are on our page to buy ivermectin tablets in the US. Use them only with a confirmed diagnosis and a prescriber's dose. For an overview of the condition, see our scabies page.

Sources

1. STROMECTOL (ivermectin) tablets, US prescribing information, Merck Sharp and Dohme (revised 09/2024). Indications, Contraindications, Warnings, Precautions (Pregnancy, Nursing Mothers, Pediatric Use), Clinical Pharmacology, Dosage and Administration Table 1. DailyMed setid 681888c9-af79-4b7d-ae80-c3f4f6f1effd.
2. Centers for Disease Control and Prevention. Clinical Care of Scabies (for health care providers), last reviewed 18 December 2023.
3. Workowski KA, et al. Sexually Transmitted Infections Treatment Guidelines, 2021: Ectoparasitic infections, scabies. Centers for Disease Control and Prevention, last reviewed 22 July 2021.
4. Centers for Disease Control and Prevention. About Scabies, last reviewed 9 September 2024; and DPDx Scabies (life cycle), last reviewed 6 June 2024.
5. Rosumeck S, Nast A, Dressler C. Ivermectin and permethrin for treating scabies. Cochrane Database Syst Rev 2018;4(4):CD012994. PMID 29608022.
6. Romani L, Whitfeld MJ, Koroivueta J, et al. Mass drug administration for scabies control in a population with endemic disease. N Engl J Med 2015;373(24):2305-13. PMID 26650152.
7. Nicolas P, Maia MF, Bassat Q, et al. Safety of oral ivermectin during pregnancy: a systematic review and meta-analysis. Lancet Glob Health 2020;8(1):e92-e100. PMID 31839144.
8. STROMECTOL product information, Australia, Merck Sharp and Dohme (revised 6 October 2023). Therapeutic Goods Administration.
9. STROMECTOL 3 mg, résumé des caractéristiques du produit. Agence nationale de sécurité du médicament (ANSM), Base de données publique des médicaments.
10. ELIMITE (permethrin) cream 5%, US prescribing information (revised 11/2023). DailyMed setid 443c0446-ccba-4f52-83ed-4c3163f35807.
11. Centers for Medicare and Medicaid Services. National Average Drug Acquisition Cost (NADAC), weekly file as of 21 October 2026.

This guide is for information and does not replace advice from a doctor or pharmacist. Scabies can look like other itchy rashes, so get the diagnosis confirmed before treating, and seek care quickly for crusted scabies, infection, or any confusion or drowsiness after taking ivermectin.