Treating head lice takes one approved lice medicine applied exactly as labeled, a nit comb, and a follow-up check 2–3 days later.
Head lice are a nuisance, not a health emergency, and they rarely justify a frantic scrub of the entire house. The bigger risk is treating before you have confirmed anything, since dandruff and a dry scalp can look a lot like nits under a bathroom light.
Once you spot live lice or nits sitting close to the scalp, the plan is short: pick a medicine matched to the person’s age, leave it on for the full labeled time, comb out the dead ones, and keep checking for a few weeks. Below is the sequence, the labeled timings, and the cleaning steps that actually matter.
How Do You Treat Head Lice Step By Step?
The working order is confirm, treat, comb, recheck, and retreat only when the label calls for it. Skipping the confirmation step is the most common reason people treat for weeks with nothing to show for it.
- Confirm it first. Look for live lice or nits sitting close to the scalp. Nits farther down the hair shaft are usually old shells, not signs of an active case.
- Skip conditioner. Do not use conditioner or a combination shampoo-conditioner before lice medicine, and take off any clothing that could get wet or stained.
- Apply the medicine exactly as labeled. Over-the-counter and prescription lice medicines both work. Keep it on for the full label-specified time, then rinse as directed. The American Academy of Pediatrics says not to shampoo hair for 24–48 hours after application.
- Put on clean clothes once the medicine is rinsed out.
- Comb out the lice and nits. Work in sections and wipe the comb on a paper towel as you go.
- Recheck every 2–3 days for 2–3 weeks, removing any nits and lice you find. This is what catches a missed hatch.
- Retreat only on schedule. If the product does not kill eggs, retreat about 7–9 days later, depending on the drug.
One caution after treatment: if a few lice are still moving slowly 8–12 hours later, do not reapply right away. If they are as active as they were before, call a healthcare provider before retreating. Also skip re-washing the hair for 1–2 days after the medicine comes off.
Getting Rid Of Lice And Nits: Which Medicine Fits Which Age
Age, weight, and whether a formula kills eggs decide the choice, not brand loyalty. Both over-the-counter and prescription lice medicines can work, and the 2022 American Academy of Pediatrics report on head lice deliberately names no favorite product.
What the report does list is who can use each product and how long to wait before retreating:
| Lice Medicine | Youngest Age Labeled | Retreat If Lice Remain |
|---|---|---|
| Permethrin 1% lotion (OTC) | 2 months | 9–10 days |
| Pyrethrins + piperonyl butoxide shampoo (OTC) | 24 months | 9–10 days |
| Ivermectin 0.5% lotion, brand Sklice (OTC) | 6 months | Single use |
| Malathion 0.5% lotion, brand Ovide (prescription) | 6 years | 7–9 days |
| Spinosad 0.9% suspension, brand Natroba (prescription) | 6 months | 7 days |
| Ivermectin 3-mg tablet, brand Stromectol (prescription) | Weight 15 kg (33 lb) or more | 9–10 days |
Retreatment timing is the part people get wrong most often. Products that do not kill eggs need a second round timed to catch newly hatched lice before they can lay eggs of their own, usually about 7–9 days later. The ivermectin lotion is the exception, built as a single application. Malathion and spinosad come into play when permethrin or pyrethrins fail despite correct use, or when resistance is documented.
Comparing formulas side by side makes the pharmacy shelf less confusing. Our roundup of tested anti-lice and nits treatments covers what each one costs and who it suits.
Cleaning Up After Lice Without Overdoing It
Only items used in the two days before treatment need attention, and fumigation never belongs in a lice plan. Lice die within a day or two off the scalp and cannot fly or hop, so a spotless house does not stop a reinfestation.
- Wash and dry what was used.
- Bag what cannot be washed. Seal non-washable items in a plastic bag for two weeks.
- Vacuum floors and furniture where the infested person sat or lay.
Skip pesticide sprays and foggers. They are not needed, they can be toxic if inhaled, and the CDC advises against them.
Four mistakes cause most failed attempts: treating without confirming an active case, using conditioner before the medicine, reapplying too soon when lice are only sluggish, and skipping the scheduled second treatment.
A child with lice does not need to be sent home early from school and can return once treatment has started.
FAQs
Do I Need To Treat Everyone In The House?
No. Only people with live lice or nits sitting close to the scalp need medicine. Lice spread through direct head-to-head contact, not through the air or shared furniture, so family members without an active infestation gain nothing from treatment, and every medicine carries its own age limits and side effects. Check each person’s scalp under bright light before deciding.
How Soon Can A Child Go Back To School?
Right away. A case of head lice is not a reason to send a student home early, and most guidance says kids can return once treatment has begun. There is no need to scrub the classroom or notify every parent. Checking siblings and close playmates at home is more useful than keeping anyone out of school.
What If Lice Are Still Moving After Treatment?
Wait and watch. A few lice crawling slowly 8–12 hours after treatment usually means the medicine is working and should not be reapplied yet. If lice look as lively as they did before, contact a healthcare provider — the case may need a different product, such as malathion or spinosad.
References & Sources
- American Academy of Pediatrics. “Head Lice” (2022 clinical report, Pediatrics) Supports the labeled ages and retreatment intervals in the product table.
- Centers for Disease Control and Prevention. “Treatment of Head Lice” Supports the washing, bagging, and no-fumigation guidance.
- Centers for Disease Control and Prevention. “Clinical Care of Head Lice” Supports the steps on applying medicine and rechecking hair.