Listerine Mouthwash: Does it Kill Lice?
If you’re struggling with lice, you know how difficult it is to get rid of it. Most lice today are immune to the over the counter treatments that worked in the past. Many parents are turning to home remedies for relief.
You may have heard that Listerine mouthwash kills lice, is it true?
This article answers the following:
Multiple studies have proven that the current strain of head lice are immune to pesticides found in over the counter treatments and most prescriptions. So, it doesn’t matter the strength or how long you leave those treatments on; they won’t kill lice!
Lice today are called “super lice” because they have genetic mutations that make them extremely difficult to kill.
A recent study shows that almost all lice today have the super lice mutation.
Does Listerine Mouthwash Kill Lice?
You may have heard that Listerine kills lice, is it true?
Some people claim that the high amount of alcohol in Listerine kills lice.
The first thing to understand is that there are many types of alcohol, and they are very different from one another. Here are the most common types:
Ethanol Alcohol (liquor)
Isopropyl Alcohol (rubbing alcohol)
Benzyl Alcohol (used in prescription medicines)
Listerine contains mint, thyme), wintergreen, and eucalyptus, and large amounts of alcohol.
Mint, thyme, wintergreen, and eucalyptus do not kill lice, so the only thing left to kill lice in Listerine is alcohol.
Listerine contains 26.9% ethanol alcohol, the only form of edible alcohol.
Many pesticides use ethanol alcohol as an additive, so this type of alcohol has been studied extensively against head lice, here’s what the studies show...
100% ethanol alcohol it can penetrate lice (study).
But, in a study immersing lice in 70% ethanol alcohol, they did not see the same results...
“A low proportion of lice were affected...in the 10-min exposure test but recovered completely after 5 min.
Different proportions of lice were affected between 2 and 7 hours after immersion in ethanol... However, a high proportion of lice recovered after 22 hours.”
What Does This Mean About Listerine?
Alcohol, oil, and other liquids can make lice immobile and go into a “coma-type” state for a while, but not kill lice.
When you submerge lice in liquid, they automatically close up their “breathing holes” so that nothing can penetrate them.
Lice submerged for long periods go into a “hibernation- state” to conserve energy. One study terms this as “playing dead."
When people use Listerine on the head for prolonged periods, they may see lice in hibernation-mode and assume that lice are dead.
The studies show that lice can remain in this hibernation state for a very long time (up to 22 hrs).
But lice “resurrect” back to life after being rinsed.
Lice are soon at full strength and capable of breeding just as they did before the treatment.
Listerine and Lice: The Experiment
Because I own my own lice salon, I am in a unique position to test something like this out, so I went ahead and did my own experiment before posting this article.
Several live lice were collected and immersed in Listerine for 15 minutes. Then the lice were removed and placed on a white paper towel in an empty mason jar.
Initially, the lice were immobile and looked dead, but I set a timer and waited...
90 minutes later… all of the lice came back to life. And all but one louse stayed alive until I finally threw them away 24 hours later.
Why Do Some People Claim Listerine Got Rid of Lice?
For every person that claims Listerine as a miracle, there is one thing in common,
“I combed the hair with a lice comb every day…”
Listerine didn’t get rid of lice; their combing got rid of lice!
It’s no big secret that combing with a lice comb gets rid of head lice.
Regardless of if Listerine kills some of the lice or not, alcohol does NOTHING for lice eggs. Lice eggs left in the hair WILL hatch if you don’t remove them from the head. And then you’ll be starting all over again.
Listerine may help immobilize lice while you’re combing, but there are better and more effective treatments and home remedies that can do that (keep reading to find out which ones).
Can Other Types of Alcohol Kill Lice?
Rubbing alcohol (isopropyl alcohol) has also been tested against lice, and it did very poorly.
Isopropyl alcohol only killed 10% of head lice.
Of home remedies, alcohol performed as one of the worst. Here’s a summary of a study that compared home remedies and other treatments.
Prescription Alcohol Treatment
The only alcohol treatment that effectively kills lice is benzyl alcohol found in the prescription lice treatment, Ulesfia™. One bottle of Ulesfia™ can cost upwards of $500. It kills lice, but the hair needs to be completely saturated (which may require more than one bottle), and you need to repeat treatments because it does nothing to kill lice eggs or prevent them from hatching.
I know you’re seeing the dollars add up...
Better Home Remedies and Treatments
For those looking for effective home remedies and treatments, I’ve got you covered.
Dimethicone is not a home remedy.
It’s not a prescription
And it’s not usually found at your local drug store.
Dimethicone is an entirely safe, non-toxic oil that suffocates and kills all lice in about 15 minutes! It outperforms everything else in killing lice.
In studies, dimethicone has an average kill rate of 98% for lice bugs with one treatment, compared to 42% for over the counter treatments or 10% for alcohol.
For years, the only places you could get dimethicone were at a professional lice center, but a few lice centers have started selling their products online, and you can purchase them through Amazon. Here are two of the best on the market:
(A quick disclosure: these are affiliate links, and I earn a commission from qualifying purchases; however, I base all of my reviews on the quality of the products)
The Ladibugs Lice Elimination Kit comes with a serum that kills both lice and super lice. It also comes with an enzyme mousse that helps loosen lice eggs, making them much easier to remove. Ladibugs is a one-and-done kit, which means you have everything you need for one person in one kit. The enzyme mousse can be used multiple times over several days to remove lice eggs.
Lice Clinics Lice Remover Kit comes with an easy dispenser and is probably the easiest treatment to use. It kills all lice within 20 minutes. You’ll need to retreat in about 10 days.
If you want to use a home remedy to smother lice, then coconut oil is your best choice.
Coconut oil is one of the more effective home remedies.
Two studies indicate that coconut oil kills about 80% of head lice if left on the head for extended periods.
I recommend leaving it on the head for at least 8 hours.
Coconut oil will be more effective if combined with an essential oil like tea tree oil, which you can find in my Tea Tree Oil Tutorial.
Unfortunately, coconut oil and tea tree oil have little to no effect on lice eggs. They neither kill lice eggs nor prevent them from hatching.
Complete removal of lice eggs from the head or several repeated treatments over 3 weeks are necessary for coconut oil to get rid of head lice effectively. Read the full article and tutorial at the article Coconut Oil For Head Lice Tutorial.
Dangers of Listerine as a Lice Treatment
If you go ahead and decide to put mouthwash or whatever type of alcohol on your child’s head, you should know there are some serious risks.
Putting a liquid form of alcohol on your child’s head is very likely to end up in their eyes. Have you ever gotten hand sanitizer in your eye? Ouch!!
In addition to being very painful, getting ethanol in your eye is very dangerous.
A study of alcohol’s effects if it gets in the eyes reports alcohol
“can cause corneal abrasions and scarring... thereby cause loss of vision and increase the risk for ocular [eye] infections.”
Considering Listerine isn’t even an effective treatment, is it worth the risk of blindness to your child?
Alcohol can be toxic to children and is very absorbent through the skin. The body can usually fight off and excrete small doses of alcohol, but in large doses, it can lead to poisoning.
Your scalp is one of the most absorbent areas of the body. Saturating the scalp with alcohol puts your child at risk of poisoning, which can lead to dizziness, vomiting, liver damage, and coma.
Children are at exceptionally high risk because their scalp is even more absorbent than adults.
Have you read the back of a Listerine bottle?
“Do not use on children under 12 years of age. Keep out of reach of children...get medical help or contact a Poison Control Center right away”
Alcohol causes severe chemical burns on the very young.
A study reporting burns on a baby related to alcohol states,
“toxic for infants and children” should appear on mass consumption products... Moreover, health workers may individually inform parents about possible hazards of poisoning through skin absorption.”
Catching on Fire!
Alcohol is extremely flammable. If your child has alcohol on their body, any exposure to any spark, they will go up in flames.
As evidenced in a news story involving an 11-year-old boy and rubbing alcohol, it can be tragic.
“An 11-year-old North Georgia boy is recovering after an accident sent him to the hospital with severe burns on 30 percent of his body…
“No one thinks that the rubbing alcohol in your medicine cabinet could possibly take the life of your child,”
“Ray is now in the burn intensive care unit...”
Vinegar and Listerine Lice Treatment
For those of you that are still planning on doing a vinegar and Listerine lice treatment, I’d love to save you some time, energy, and sanity.
Vinegar does nothing for lice or lice eggs!
Did you see which home remedy performed worse than Listerine in studies? It was vinegar, killing only 2% of head lice.
Some people claim that the acidity of apple cider vinegar eats away at the glue that holds lice into place on the hair strand, which makes them easier to remove.
It’s just simply not true. Tests of vinegar on lice eggs, and it doesn’t do anything. It doesn’t loosen them, kill them, or prevent them from hatching.
As someone who removes lice and lice eggs from people’s hair every day, I have not seen a difference in vinegar, easing the removal of lice eggs.
I think more likely people are looking for a “cure” against lice eggs, and they want to believe apple cider vinegar makes a difference, but it doesn’t.
How to Remove Lice Eggs
The fastest, easiest, and most effective way to get rid of lice eggs is with a professional-level head lice comb.
I know what you’re thinking: “I’ve tried lice combs, and they don’t work.”
That’s because you’re using a lousy comb.
The very best lice comb out there is the Nit-Free Terminator Comb, and you can’t find it at the drugstore.
The Terminator is the comb I use every day in my lice center. If you ask any lice professional, they will almost certainly tell you this is the comb they use.
The teeth of this comb are spaced tightly together, but the real secret is that these teeth have small spirals, creating a “barbed wire” effect on lice and nits, catching them and dragging them down the entire hair strand and out of your child’s hair.
The most important part of getting lice eggs out of the hair is using the Nit Free Terminator Comb. But, if you’re looking for a way to break down the glue that holds nits in place, enzymes can help. The Ladibugs Kit comes with an enzyme mousse that you leave on the hair before combing through it, which is why it is my top pick for treatment kits.
Another enzyme product that works well at eating away at lice eggs is LiceLogic Clear & Free Shampoo. Enzyme shampoos like this take time to eat away the lice glue, so they work best if you use them multiple times. LiceLogic’s enzyme shampoo is a full 8 oz, so there is enough for the whole family for multiple uses.
Listerine for Lice Prevention
I’ve read some things on the web suggesting spraying Listerine in your child’s hair to help with lice prevention.
Some of the ingredients in Listerine (mint, spearmint, and eucalyptus) have some repelling properties in them, but Listerine will not prevent lice.
Plus, your child will smell like...well, mouthwash! And alcohol! No, thank you!
Putting certain fragrances in the hair can keep lice away, but Listerine is nowhere on the list. If you want to prevent head lice, these are the scents to do it with:
- Peppermint (caution for kids under 6)
- Tea Tree aka Melaleuca
- Citronella or Geraniol
- Eucalyptus (caution for kids under 10)
- Lemon Eucalyptus (caution for kids under 3)
- Rosemary (caution for kids under 6)
- Lemongrass (caution for kids under 2)
- Ylang Ylang (caution for kids under 2)
- Anise (Anniseed oil) (caution for kids under 6)
If you want to make your own lice prevention spray, check out my DIY Lice Spray Tutorial.
Tried and True Lice Prevention Sprays
There are some very effective lice prevention sprays already on the market. These sprays are a combination of all of the best prevention essential oils. Instead of making one yourself, you can buy one. I review all lice prevention sprays in this article but below are the best.
Listerine Mouthwash on Furniture
Please don’t put Listerine on your furniture in an attempt to kill head lice. Your house will smell terrible for months! I outline everything you need to do to clean your home in the article House Cleaning Checklist to Get Rid of Lice in Your House.
Summing it Up…
Listerine does not kill head lice. Although lice may “play dead” if submerged in alcohol for long periods, they “resurrect” back to life.
The only form of alcohol that kills lice effectively is a prescription treatment of Benzyl alcohol, Ulesfia™. Benzyl alcohol is not the same alcohol as alcohol in Listerine.
Using Listerine mouthwash as a lice treatment is very dangerous. It can cause eye injury, blindness, skin burns, poisoning, and your child can easily catch on fire. Since Listerine is not a good lice treatment, it’s not worth the risk.
If you are looking for a home remedy, I suggest coconut oil, which has an 80% kill rate. If you want to get rid of lice faster, then use a dimethicone treatment like the Ladibugs Kit or the Lice Clinics Kit and a Nit Free Terminator comb.
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