Getting lice out of your hair takes a combination of killing live lice, removing their eggs (called nits), and repeating the process to catch any stragglers that hatch over the next week or two. A single treatment almost never finishes the job because nits take 6 to 9 days to hatch, and most treatments don’t kill unhatched eggs. The full process typically takes about two weeks from start to finish.
Confirm It’s Actually Lice
Before you start treating, make sure you’re dealing with lice and not dandruff or dry scalp. Nits are tiny, clear or white oval specks that cling to individual hair strands close to the scalp. The key difference: dandruff flakes off easily when you brush or shake your hair, while nits are glued to the hair shaft and won’t budge unless you slide them off with your fingernails or a fine-toothed comb. You might also spot live lice, which are about the size of a sesame seed and move quickly away from light.
Check behind the ears and along the neckline first. These warm spots are where lice prefer to lay eggs.
Over-the-Counter Lice Treatments
The most common first step is an OTC lice-killing product, usually a shampoo or cream rinse containing permethrin or pyrethrin. You apply it to damp hair, leave it on for the time listed on the package, then rinse. These products kill live lice on contact but generally don’t destroy unhatched nits, which is why a second treatment is essential.
One important caveat: many lice populations have developed resistance to these older ingredients. If you use an OTC treatment and still see live, crawling lice two or three days later, the product likely isn’t working and you’ll need a different approach.
Prescription Options When OTC Fails
If over-the-counter products don’t clear things up, several prescription treatments work through different mechanisms that resistant lice can’t dodge. Some are approved for children as young as six months old, while others are meant for kids six and older. These prescription options tend to be more effective in a single application, and some kill both live lice and nits. Your pediatrician or doctor can match the right one to your child’s age and situation.
The Wet Combing Method
Whether you use a medicated treatment or not, physically combing out lice and nits is one of the most reliable parts of the process. The NHS recommends a structured wet combing schedule that catches newly hatched lice before they’re old enough to lay their own eggs. Here’s how it works:
- Wash and condition the hair. Use ordinary shampoo, then apply a generous amount of any conditioner. The conditioner slows lice down so they can’t run from the comb, and it helps the comb glide through without pulling.
- Comb from roots to tips. Use a fine-toothed lice comb (sometimes called a detection comb, available at any pharmacy). Work through every section of hair from the scalp all the way to the ends. Wipe the comb on a white paper towel after each pass so you can see what you’re pulling out.
- Comb the entire head twice. Once you’ve gone through all the hair, start over and do a second pass to catch anything you missed.
- Repeat on a schedule. Comb on days 1, 5, 9, and 13. Check again on day 17 to confirm the hair is clear. This schedule is timed to the lice life cycle: nits hatch in about a week, and nymphs take another 7 days to mature into egg-laying adults. By combing every few days, you remove newly hatched nymphs before they can reproduce.
Expect each session to take about 10 minutes for short hair and 20 to 30 minutes for long, curly, or thick hair. It’s tedious, but it’s the step that makes the biggest difference.
Why You Need a Second Treatment
Understanding the lice life cycle explains why one round of treatment isn’t enough. Nits hatch 6 to 9 days after they’re laid. The baby lice (nymphs) that emerge go through three growth stages over about 7 more days before becoming adults. Adults can live up to 30 days on a human head, laying eggs the entire time.
Most medicated treatments kill live lice but leave nits intact. The second application, typically done 7 to 9 days after the first, targets the nymphs that hatched from those surviving eggs before they’re mature enough to start laying new ones. Skip this step and you’re likely to end up right back where you started.
What About Home Remedies?
You’ll find plenty of suggestions online for smothering lice with olive oil, mayonnaise, petroleum jelly, or butter. The idea is to coat the hair thickly, cover it with a shower cap, and leave it overnight to suffocate the lice. According to the Mayo Clinic, there’s little to no proof that these methods actually work. Some people do report success, but the results are inconsistent, and none of these approaches have been tested the way medical treatments have.
Essential oils like tea tree oil are another popular suggestion. These aren’t regulated the same way as medical treatments, and they can cause allergic reactions in some people. If you want to try a non-chemical approach, structured wet combing on the day 1, 5, 9, 13, 17 schedule is the best-studied alternative.
That said, conditioner, mayonnaise, petroleum jelly, or silicone-based products can be useful as lubricants during wet combing. They slow the lice down and make the comb glide more easily. Using them as combing aids is different from relying on them as standalone treatments.
Cleaning Your Home
Lice can’t survive long off a human head, but a little household cleanup reduces the chance of reinfestation. Focus only on items the affected person used in the two days before treatment. Lice that fall off the scalp die within a day or two without a blood meal, so anything untouched for 48 hours is already safe.
- Bedding, towels, and clothes: Machine wash in hot water (at least 130°F) and dry on high heat.
- Combs and brushes: Soak in hot water (at least 130°F) for 5 to 10 minutes.
- Items you can’t wash: Seal them in a plastic bag for two weeks. Any lice or nits inside will die without access to a host.
You don’t need to deep clean the entire house, fumigate, or throw anything away. Lice spread through direct head-to-head contact, not from furniture or carpets. Vacuuming upholstered furniture and the floor around the bed is a reasonable precaution, but spraying insecticides indoors is unnecessary and not recommended.
Preventing Reinfestation
The most common reason lice come back isn’t a dirty house. It’s head-to-head contact with someone who still has them. Check every member of the household at the same time and treat anyone who has live lice or nits. If your child got lice at school or a sleepover, let the other parents know so they can check too.
Lice don’t jump or fly. They crawl from one head to another during close contact, like hugging, sharing a pillow, or leaning heads together over a phone screen. Sharing hats, helmets, brushes, or hair accessories carries a smaller but real risk. Teaching kids to avoid sharing these items helps, though the biggest factor is simply reducing prolonged head-to-head contact during an active outbreak.