Does Mayonnaise Kill Lice?
If you search online for remedies to eliminate head lice, you’ll find all sorts of products and recommendations—from traditional lice treatments available at drug stores and online-only alternative products to home treatments using common household products. One of the most commonly recommended household products suggested to treat lice is mayonnaise.
You might be wondering: does it really work to kill lice? The short answer is: not effectively, and it can actually pose some health risks.
Why is mayonnaise a popular lice treatment option?
Mayonnaise is a popular treatment option because it’s a household item that’s inexpensive and easily accessible; and while it can work in certain circumstances, it can pose some significant health risks too.
The idea behind using mayonnaise is that the thick pasty substance will clog the insects’ breathing mechanism, suffocating each louse to death over a period of time. The theory is that you simply leave mayonnaise on the child’s head overnight (wrapping the head in a plastic bag to keep the mayonnaise off the pillow); when you wash it out in the morning, the lice will hypothetically be dead and easy to remove.
Unfortunately, there are some problems that come with using this treatment method.
Why doesn’t mayonnaise work to kill or treat lice?
Lice need both air and water to live. They transfer those through their trachea and spiracles (which are holes along their bodies). As a result, you might think it’s possible to smother and then suffocate them using a thick substance like mayonnaise or another everyday household product such as Cetaphil. However, a louse can hold its breath for many hours at a time – so in order for this to work, the agent must remain on the scalp at least overnight, if not longer.
Additionally, this smothering technique will only work on hatched lice – not eggs themselves. A louse incubating inside the egg just gets coated with mayo or Cetaphil, but because eggs do not need any external nutrients, it has no effect on them. This means that even if you kill all of the hatched lice, once you remove the smothering agent, the eggs will remain and eventually hatch themselves – creating a whole new problem!
Why is it dangerous to use mayonnaise as a treatment method?
Unfortunately, there are some dilemmas with trying to smother lice with this approach: inefficacy and the potential danger from suffocation & food poisoning.
Using mayonnaise or Cetaphil is an ineffective technique for combating lice, as confirmed by the Center for Disease Control and Prevention (CDC): “The CDC does not have clear scientific evidence to determine if suffocation of head lice with mayonnaise, olive oil, margarine, coconut oil, tea tree oil, butter, or similar substances is an effective form of treatment.” (Source)
As we mentioned, smothering lice will not kill eggs.
Lice have a very short life cycle. Female lice can lay around 5 eggs per day, and each egg takes 7-10 days to hatch. Lice eggs, also known as nits, are almost indestructible (learn more here). Nits affix to hair follicles with tremendous strength, and odds are that when you rinse the mayo out of a child’s head, they will still be there and hatch a few days later.
This technique is ineffective, takes a lot of time, and can be dangerous.
Smothering lice through mayonnaise takes a long time, and as a result parents often leave the treatment on overnight. However, as any parent knows, plastic bags/wrapping should never be placed over a child’s head because of the risk of suffocation and death. A plastic bag or wrapping left on all night could slip over a child’s mouth and suffocate them in their sleep, making it far too great a risk to endure.
In addition, mayonnaise goes bad quickly because of its components – and in fact “potato salad” is the most frequent cause of food poisoning for residents of the United States. Spoiled mayonnaise could easily be inhaled or ingested by a child and lead to food poisoning.
Alternative Safe & Effective Treatments for Head Lice
None of these risks make this technique worth it! Instead, we suggest using solutions developed by scientists at the University of Utah and approved by the FDA (food and drug administration) for their safety and efficacy.
This is great news for parents, school nurses, teachers, and others involved in the battle against head lice. Instead of using messy and dangerous methods to treat lice, there is now a proven removal process that is safe and effective.
Lice Clinics of America has developed a dimethicone product for safely smothering lice. Dimethicone is a silicone used to kill lice, which lacks some of the same setbacks that mayonnaise and Cetaphil have.
For one, it only has to be left on for about a half hour, rather than hours and hours, requiring the overnight treatment needed in the “mayo technique;” secondly, it’s not as messy! And finally, it won’t lead to food poisoning like mayo. It’s quick and easy: clients who get treated with dimethicone at our clinics can simply rinse it out after their drive home.
The AirAllé Device
Lice Clinics of America has also developed an FDA-cleared medical device known as AirAllé, desiccates lice and nits. For a truly comprehensive lice treatment experience, we recommend the use of the AirAllé, a professional comb-out, and the treatment of dimethicone. Dimethicone works excellently on hatched lice, and the AirAllé device rounds out the process by successfully exterminating unhatched nits. The AirAllé device uses carefully controlled heated air to dehydrate and kill head lice. It has been proven to kill live lice and 99.2 percent of lice eggs, and the entire process takes about 90 minutes!
If you have heard that using mayonnaise (or Cetaphil) to smother lice is a safe and effective tool, unfortunately, you have gotten incorrect advice. We advise you to stick to products with high efficacy, and that do not put your child at risk. Using mayo is ineffective and dangerous.
At Lice Clinics of America, we developed our products with parents in mind, so families could easily treat lice without worry. If you or your family have been suffering from lice infestations for far too long, find your nearest Lice Clinic and get treated today.