How does Cartwheel rank its own product fairly?

Nit Happens is graded on the same five criteria as everything else, over the counter and prescription products are ranked separately, and the limits of its study (26 participants, single arm, not peer reviewed) are stated next to its result. The full report and dataset are public.

Best lice treatment 2026, ranked by the evidence

Q: Is the expensive treatment worth it?

The real cost of a cheap pesticide shampoo is often two boxes plus a week of lice, then a better product anyway. A $35 to $50 product that works the first time is cheaper than that, and far cheaper than a $100 to $500 salon visit per head.

By Joanna Shu, founder and CEO of Cartwheel. Updated October 29, 2026. Cartwheel makes Nit Happens. It is graded below on the same five criteria as everything else, over the counter products in one list and prescription drugs in another, because families do not choose between a drugstore kit and a doctor visit the same way. Every number is sourced; the list is at the end.

The short version: the best head lice treatment in 2026 is one that does not depend on the lice being susceptible to pesticides, because about 98% of US head lice now carry resistance to permethrin and pyrethrins, the ingredients in Nix, RID and most store brands. Over the counter, the Nit Happens kit (our product) has the highest reported lice free rate of anything on the shelf, 89% counting everyone enrolled and 95.8% when two judged re-infestations are excluded, is pesticide free, includes the metal comb and costs $34.99. Ivermectin lotion and dimethicone are the other drugstore options with evidence behind them. With a prescription, spinosad has the strongest randomized trials and oral ivermectin is the fallback for failed cases. Wet combing alone works for patient families. Nix and RID are the cheapest option and the most likely to fail.

How we graded

Each option was scored on five things, then given a letter grade. Where a number exists, we used it; where it does not, we say so.

Cure rate in trials. The share of people lice free at the end of the study, as the investigators reported it. Randomized trials with a comparison arm count for more than single arm studies.
Resistance risk. Whether the product's mechanism is affected by the knockdown resistance (kdr) mutations found in 98.3% of US lice sampled across 48 states.
Youngest labeled age. From the US label or instructions for use.
Cost per person. Retail and coupon prices checked October 2026.
Effort. Applications, combing time and whether a visit or prescription is needed.

Grades: A strong evidence, resistance proof, available without a visit. B good evidence with a caveat on study design, cost or access. C works but with a real cost in money, time or availability. D expected to fail for most US families. F no credible evidence. Over the counter and prescription are ranked separately.

Over the counter, ranked

1. Nit Happens Complete Lice Treatment Kit Cartwheel's product

Lice free 89% at day 15 counting all 26 enrolled (23 of 26); 95.8% when two participants judged by the investigators to be re-infestations are excluded; 0 adverse events [10] · Labeled for ages 3 and up · $34.99 per person, HSA and FSA eligible · Gel on dry hair, rinse with the shampoo, comb with the metal comb; second application 7 to 10 days later

Why it ranks first: the highest reported lice free rate of any over the counter option on this page, no pesticides and no parabens so resistance is irrelevant, the metal comb is in the box, and it is $34.99 at Walgreens nationwide, on Amazon and here. The caveat, stated plainly: the H.A.L.T. study was a single arm study of 26 people and is not peer reviewed, and we are the company selling it. We publish the full report and row level dataset so anyone can check the numbers. Best for: families who want one box that handles the whole job tonight.

A-

2. Ivermectin 0.5% lotion (Sklice, over the counter)

Cure rate 73.8% at day 15 after a single application vs 17.6% with vehicle [4] · Ages 6 months and up · About $50 with a coupon, up to $180 retail [11] · One 10 minute application

Why it ranks here: randomized evidence, a single application, no nit combing required on the label, and the youngest age floor of any drugstore product. The catch: price. It is the most expensive thing on the shelf, and the trial result is lower than the Nit Happens study's.

3. Dimethicone 4% lotion (several brands, over the counter)

Cure rate 69.8% vs 33.3% with malathion in a randomized UK trial [7] · Age varies by brand, commonly 2 and up · $15 to $30 · Two applications a week apart, 8 hours or overnight in some brands, plus combing

Why it ranks here: a physical coating that resistance cannot touch, with a proper randomized trial behind it. The catch: US dimethicone products vary in concentration and leave on time, and most do not include a good comb, so check the label and budget for one.

C+

4. Wet combing alone (conditioner and a metal nit comb)

Cure rate 57% vs 13% for a single over the counter pesticide treatment, randomized trial [9] · Any age · $10 to $20 for a good metal comb · Four to five sessions of 30 to 60 minutes over two weeks

Why it ranks here: it beats pesticide shampoo, costs almost nothing and is the right answer for babies under the youngest labeled ages. The catch: it only works if you actually do every session, and most families miss one. The technique is here.

5. Permethrin 1% creme rinse (Nix and store brands)

Cure rate 44.9% and 42.9% at day 14 in the 2009 control arms [3], before resistance climbed to 98.3% nationally [2] · Ages 2 months and up · $10 to $25 · Two 10 minute applications plus combing

Why it ranks here: it was the standard for thirty years and it is cheap. Why it fails now: the kdr mutations that disable it were found in 100% of lice sampled in 42 of 48 states. If you have already used it and still see live lice a day later, that is the expected result, not user error. Switch to a different type of treatment rather than buying a second box. Nix vs RID compared.

6. Pyrethrins with piperonyl butoxide (RID and store brands)

No recent US cure rate to cite; same resistance mechanism as permethrin [2] · Ages 2 and up · $10 to $25 · Two 10 minute applications plus combing

Why it ranks here: the same mutations that stop permethrin stop pyrethrins. RID now also sells pesticide free versions under the same brand name, so read the active ingredient on the box rather than the logo.

Not graded: mayonnaise, olive oil, vinegar, essential oils, rubbing alcohol, vodka

Why: no controlled trial shows any of them clears an infestation, several are unsafe on a child's scalp, and the time spent on them is time the lice spend laying eggs. What alcohol actually does to lice.

With a prescription, ranked

These need a pediatrician or telehealth visit ($25 to $150) on top of the drug. They are the right call when an over the counter treatment has been done correctly twice and live lice are still there, or when a pediatrician prefers a drug for a particular child.

1. Spinosad 0.9% suspension (Natroba)

Cure rate 84.6% and 86.7% at day 14 in two randomized trials vs 44.9% and 42.9% for permethrin [3] · Ages 6 months and up · $32 to $300 after coupons plus the visit [11] · One 10 minute application, no combing required on the label

Why it ranks first among prescriptions: the best head to head trial evidence of any lice drug, working by a pathway US lice have not become resistant to. The catch: cost, and the visit.

2. Oral ivermectin tablets (off label for lice)

Cure rate 95.2% at day 15 vs 85.0% for malathion lotion, in hard to treat cases [5] · Not for children under 15 kg (about 33 lb) · Two doses a week apart

Why it ranks here: the highest cure rate on the page, from a randomized trial. Why it is not first: it is a systemic drug used off label, with a weight minimum, and pediatricians reserve it for cases where topical treatment has failed.

C+

3. Benzyl alcohol 5% lotion (Ulesfia)

Cure rate 76.2% and 75.0% at day 14 vs 4.8% and 26.2% with vehicle [6] · Ages 6 months and up · Ask whether your pharmacy stocks it · Two 10 minute applications a week apart

Why it ranks here: solid trials and a suffocation mechanism that resistance does not affect. The catch: not widely stocked, and it does not kill eggs, so the second application is not optional.

Also: heated air treatment at a lice salon (no prescription, but an appointment)

Killed 80% of hatched lice and 98% of eggs in one trial run by the device's inventors [8] · Age limits set by each salon · $100 to $500 per head, plus $10 to $50 head checks and a separate charge for each family member [11] · One appointment of 60 to 90 minutes

Why it ranks here: it works, and some families want someone else to do it. The catch: a salon visit for a family of four can cost more than a year of school lunches, and the published evidence is a single study from the people who built the machine. Cost comparison here.

Side by side

Treatment	Grade	Lice free in trials	Evidence type	Resistance proof	Youngest age	Cost per person	Rx needed
Nit Happens kit (ours)	A	89% all enrolled; 95.8% two re-infestations excluded [10]	Single arm, n=26	Yes	3 years	$34.99	No
Ivermectin 0.5% lotion	A-	73.8% [4]	Randomized trial	Yes	6 months	$50 to $180	No
Dimethicone 4%	B	69.8% [7]	Randomized trial	Yes	Varies, often 2	$15 to $30	No
Wet combing alone	C+	57% [9]	Randomized trial	Yes	Any	$10 to $20	No
Permethrin 1% (Nix)	D	42.9% to 44.9%, 2009 [3]	Control arms	No	2 months	$10 to $25	No
Pyrethrins (RID)	D	No recent US figure	None recent	No	2 years	$10 to $25	No
Spinosad 0.9%	A (Rx)	84.6% to 86.7% [3]	Two randomized trials	Yes	6 months	$32 to $300 plus visit	Yes
Oral ivermectin	B (Rx)	95.2% hard to treat cases [5]	Randomized trial	Yes	15 kg	Rx plus visit	Yes, off label
Benzyl alcohol 5%	C+ (Rx)	75.0% to 76.2% [6]	Two randomized trials	Yes	6 months	Rx, limited stock	Yes
Heated air (salon)	C	80% of lice, 98% of eggs killed [8]	One trial by the inventors	Yes	Set by salon	$100 to $500 per head	No

Which one should you buy tonight?

Child 3 or older, you want it done at home, no prescription: a pesticide free kit with a metal comb. Nit Happens is ours ($34.99, Walgreens, Amazon, here); dimethicone lotion plus a separate comb is the other drugstore route.
You want a single application and price is no object: ivermectin 0.5% lotion over the counter.
Baby under 3: call the pediatrician. Wet combing is the only option with no age floor; ivermectin lotion, spinosad and benzyl alcohol are labeled from 6 months with a prescription or pharmacist's guidance.
You already used Nix or RID and there are live lice: do not buy it again. Pick anything graded A or B over the counter.
Two treatments have failed and you did them right: pediatrician visit, and ask about spinosad or oral ivermectin.

Not sure it is lice at all? Itching alone is not a diagnosis and about four in ten specimens parents bring in are not lice. Use the two minute lice checker first.

Whatever you choose, do these four things

Treat only people with live lice or nits within a quarter inch of the scalp. The AAP advises against treating "just in case" [12].
Check everyone in the house the same day. Bedmates are most likely to have it [1].
Do the second application when the label says, usually 7 to 10 days later. Eggs hatch in 8 to 9 days and no product kills every egg [1].
Hot wash and hot dry the hats, pillowcases and towels from the last two days; bag what cannot be washed for two weeks. Skip the sprays and foggers [1].

Questions people ask

What is the most effective lice treatment in 2026?

Over the counter, the Nit Happens kit has the highest reported lice free rate, 89% counting everyone enrolled and 95.8% when two judged re-infestations are excluded, followed by ivermectin lotion (73.8%) and dimethicone (69.8%). With a prescription, spinosad (84.6% to 86.7%) and oral ivermectin (95.2% in hard to treat cases) lead. Cartwheel makes Nit Happens.

Why do Nix and RID not work anymore?

About 98% of US head lice carry knockdown resistance mutations that stop permethrin and pyrethrins from working. In 42 of 48 states sampled, every louse tested carried them. The products did not change; the lice did.

What is the best lice treatment that is not a pesticide?

Over the counter, the Nit Happens kit, whose gel kills lice and nits and whose metal comb removes them, has the highest reported lice free rate; dimethicone lotion and wet combing are the other physical options. Ivermectin lotion, spinosad and benzyl alcohol are drugs that work by mechanisms resistance does not affect.

What is the best lice treatment for kids under 2?

Wet combing has no age floor. Permethrin 1% is labeled from 2 months but is unlikely to work. Ivermectin lotion, spinosad and benzyl alcohol are labeled from 6 months. Nit Happens is labeled for ages 3 and up. Under 3, call your pediatrician before using anything.

Is the expensive treatment worth it?

Usually the real cost of a cheap pesticide shampoo is two boxes plus a week of lice, then a better product anyway. A $35 to $50 product that works the first time is cheaper than that, and far cheaper than a $100 to $500 salon visit per head.

How do you rank your own product fairly?

We grade it on the same five criteria as everything else, rank over the counter and prescription products separately, and state the limits of its study in the same place we state its result: 26 participants, single arm, not peer reviewed. The full report and row level dataset are public so you can judge for yourself.

Should my child stay home from school?

No. The CDC says children do not need to be sent home early, and the AAP says no healthy child should miss school because of lice and that no nit policies should be abandoned. Treat that evening and send them back in the morning.

How to cite this page

Shu J. Best lice treatment 2026, ranked by the evidence. Cartwheel, October 29, 2026. https://gocartwheel.com/pages/best-lice-treatment. Related: head lice statistics, clinical evidence, do I have lice.

Sources

Centers for Disease Control and Prevention. About Head Lice; Treatment of Head Lice. cdc.gov/lice. Accessed October 29, 2026.
Gellatly KJ, Krim S, Palenchar DJ, et al. Expansion of the Knockdown Resistance Frequency Map for Human Head Lice in the United States Using Quantitative Sequencing. Journal of Medical Entomology 2016;53(3):653-659.
Stough D, Shellabarger S, Quiring J, Gabrielsen AA. Efficacy and safety of spinosad and permethrin creme rinses for pediculosis capitis (head lice). Pediatrics 2009;124(3):e389-e395.
Pariser DM, Meinking TL, Bell M, Ryan WG. Topical 0.5% ivermectin lotion for treatment of head lice. New England Journal of Medicine 2012;367:1687-1693.
Chosidow O, Giraudeau B, Cottrell J, et al. Oral ivermectin versus malathion lotion for difficult to treat head lice. New England Journal of Medicine 2010;362:896-905.
Meinking TL, Villar ME, Vicaria M, et al. The clinical trials supporting benzyl alcohol lotion 5% (Ulesfia). Pediatric Dermatology 2010;27(1):19-24.
Burgess IF, Lee PN, Matlock G. Randomised, controlled, assessor blind trial comparing 4% dimeticone lotion with 0.5% malathion liquid for head louse infestation. PLoS ONE 2007;2(11):e1127.
Goates BM, Atkin JS, Wilding KG, et al. An effective nonchemical treatment for head lice: a lot of hot air. Pediatrics 2006;118(5):1962-1970.
Hill N, Moor G, Cameron MM, et al. Single blind, randomised, comparative study of the Bug Buster kit and over the counter pediculicide treatments against head lice in the United Kingdom. BMJ 2005;331:384-387.
Villar ME, Rubio Rivera S. H.A.L.T. Lice Treatment Kit clinical study, final clinical report, December 3, 2020. Commissioned by Arbor Development; the formulation is sold as Nit Happens by Cartwheel (FreezeNit, Inc.), the licensee and manufacturer. Report, summary and dataset: doi:10.5281/zenodo.23510395.
Cartwheel. How much does lice treatment cost? Kit vs salon vs prescription (2026). gocartwheel.com/blogs/news/how-much-does-lice-treatment-cost. Prices checked October 2026.
Nolt D, Moore S, Yan AC, Melnick L; American Academy of Pediatrics. Head Lice. Pediatrics 2022;150(4):e2022059282.

This page is general information, not medical advice. Cartwheel makes and sells Nit Happens and has no financial relationship with any other product named here. Age limits and application steps come from US labels as of October 2026; follow the label in the box.