Head lice can be treated at home with a combination of a topical product and thorough combing, repeated over two to three weeks. The key to success is understanding that no single treatment kills both live lice and their eggs in one session. You need at least two rounds of treatment, timed to catch newly hatched lice before they can lay more eggs.
Confirm You’re Dealing With Lice
Before you treat, make sure lice are actually the problem. Nits (lice eggs) are white or yellowish-brown specks attached to the hair shaft, usually within a quarter inch of the scalp. The easiest way to tell them apart from dandruff: try to flick the speck off. Dandruff slides away easily, but nits are cemented to the hair and won’t budge without effort.
Live lice are small, grayish-tan insects that move quickly and avoid light. Part the hair in small sections under a bright lamp and look especially behind the ears and along the nape of the neck. If you see nits but no live lice, you may be looking at an old, already-resolved infestation. Nits found more than a quarter inch from the scalp have likely already hatched or are no longer viable.
Choose the Right Treatment Product
Head lice have developed widespread resistance to the traditional over-the-counter chemicals, specifically permethrin and pyrethrins. These are the active ingredients in many of the best-known drugstore treatments, and while they still work in some cases, resistance has made them unreliable. The CDC acknowledges that lice have developed resistance to both, though the exact prevalence is unknown.
Products that work through physical mechanisms rather than chemical nerve toxins are now considered more effective. Look for treatments containing dimethicone (a type of silicone), benzyl alcohol, or spinosad. Dimethicone works by coating the lice and disrupting their ability to manage water, essentially suffocating them. Because this is a physical process, lice can’t develop resistance to it the way they can to pesticides.
If you try a permethrin-based product first and still find live lice crawling 8 to 12 hours after treatment, resistance is likely the reason. Switch to a dimethicone-based product or talk to a pharmacist about alternatives.
How to Apply Treatment
Follow the product instructions exactly, especially regarding how long to leave it on and whether hair should be dry or damp during application. Most treatments are applied to dry hair, left on for a specified time, then rinsed. A few important rules apply to all products:
- Don’t use on open sores. If the scalp has raw or broken skin from scratching, the treatment can cause further irritation.
- Apply only to the scalp and hair. You don’t need to treat the whole body.
- Don’t use conditioner before applying. Conditioner coats the hair shaft and can reduce the product’s effectiveness.
After the treatment sits for the recommended time and is rinsed out, begin combing.
Wet Combing Is Essential
A nit comb is a fine-toothed comb specifically designed to pull eggs and lice off the hair shaft. No treatment product removes nits on its own, so combing is not optional. Cat flea combs also work well for this purpose.
Start by sectioning the hair into small parts. Work from the scalp outward to the ends, wiping the comb on a paper towel after each pass so you can see what you’re pulling out. Adding conditioner or a detangling spray makes the process easier and helps the comb glide through without pulling. For thick or curly hair, smaller sections and more conditioner will save time and frustration.
Plan to spend 30 to 60 minutes on the first combing session, depending on hair length and thickness. After the initial treatment, comb through and check the hair every two to three days for the next two to three weeks. This ongoing checking is what catches any nymphs that hatch after the first treatment before they mature enough to reproduce.
Why Timing the Second Treatment Matters
Lice eggs hatch in six to nine days. Once hatched, nymphs take about seven more days to become adults capable of laying new eggs. This gives you a window: if you retreat around day nine after the first application, you can kill newly hatched nymphs before they start the cycle over again.
Most product labels recommend a second treatment seven to ten days after the first. This timing is based on the lice life cycle and is critical to success. Skipping the second treatment is the most common reason home treatment fails, because eggs that survived the first round will hatch and reestablish the infestation within days.
Adults can survive up to 30 days on a person’s head, so the two-to-three-week monitoring window after treatment is there to catch any stragglers.
What About Home Remedies?
Mayonnaise, olive oil, coconut oil, and petroleum jelly are all popular suggestions. The idea is that coating the hair in something thick will suffocate the lice. In practice, these substances may slow down live lice, but they do not kill eggs. If you use one of these methods and skip proper combing and retreatment, the eggs will hatch and you’ll be right back where you started.
Tea tree oil has shown some promise in lab studies. Research has found it can kill lice in the nymph and adult stages and reduce egg hatching rates. One clinical study found that a tea tree and lavender oil combination cleared lice in nearly all treated children. Tea tree oil also appears to have a mild repellent effect. However, no specific concentration has been proven clinically effective, and results vary widely. It’s best thought of as a possible supplement to a proven treatment, not a replacement for one.
Some remedies are genuinely dangerous. Never use gasoline, kerosene, or any flammable substance on hair. At least one child death has been linked to a plastic bag placed over hair during a home treatment, when the bag slipped over the child’s face. If you notice skin irritation, rawness, or unusual behavior after applying any product, stop using it.
Cleaning Your Home
Lice cannot survive more than one to two days off a human head, and nits need the warmth of the scalp to hatch. This means your house does not need to be deep-cleaned or fumigated. Focus your effort on items that touched the infested person’s head in the last 48 hours.
Wash pillowcases, sheets, hats, scarves, and recently worn clothing in hot water (at least 130°F) and dry on the highest heat setting. Items that can’t be washed, like stuffed animals or decorative pillows, can be sealed in a plastic bag for two weeks. That’s long enough for any lice or nits to die. Vacuum upholstered furniture and car seats where the person’s head rested. Soak hairbrushes and combs in hot water (at least 130°F) for five to ten minutes.
Skip the lice sprays for furniture and carpets. They’re unnecessary, and they add chemical exposure without meaningful benefit. Lice spread through direct head-to-head contact, not from couches or carpets.
Check Everyone in the Household
Anyone living in the same home should be checked for lice, but only those with confirmed live lice or nits close to the scalp should be treated. Preventive treatment of people who don’t have lice isn’t recommended. If more than one person is infested, treat everyone on the same day to prevent passing lice back and forth.
For the two to three weeks following treatment, check treated family members every few days with a nit comb. If you’re still finding live lice after a full course of two treatments with the same product, the lice are likely resistant to that product’s active ingredient, and it’s time to switch to a different type.