Listerine Lice Treatment: Why It Doesn't Work

The Rundown

First of all, don’t use Listerine as a treatment for lice. Just don’t. It may be an appealing alternative due to its price when compared to the price of lice shampoos and treatments, but that’s because it’s not a lice shampoo.

To be classified as a lice treatment, products must go through extensive testing by the FDA and other regulatory agencies, submitted in clinical trials, and proven to be consistently effective. Listerine has not done that. It is a mouthwash, not a lice shampoo.

The Ingredients

Listerine
Active Ingredients: Alcohol (30%)
Other ingredients: Eucalyptol, Thymol, Menthol, Methyl Salicylate

Suffocation vs. Dehydration

The reason Listerine doesn’t work to eliminate lice is that different chemicals treat lice differently. The active ingredient in Listerine is alcohol, and alcohol-based alternative lice treatments (like Listerine) predominantly rely on suffocation to eliminate lice. This is a good step, but far from an effective, permanent solution.

Head lice in the egg stage have a protective, waxy coating that acts as a waterproofing agent and allows them to continue their evolution into live nits. (While Listerine may loosen some of the eggs, it’s not enough.) The alcohol in Listerine deprives the eggs of oxygen in order to suffocate them; however, it can take 8-24 hours for suffocation to occur. In that time, the lice eggs can lie dormant and the Listerine wears off. As a result, the affected party will need almost constant Listerine treatments over the course of several days to ensure the lice eggs don’t hatch. In addition, any live nits and eggs will still have to be combed out with a special lice comb.

Method

Why, then, do some people swear by Listerine? The secret may be more in the act than in the ingredients. Many articles that identify this particular method as a solution also call for the use of a lice comb and vinegar. It is more likely the act of combing out the lice with a lice comb, combined with the vinegar, that eliminates the lice more than the active ingredients in Listerine themselves.

Remember those breakfast cereal commercials on Saturday mornings for Apple Jacks that said “part of this complete breakfast,” then showed the sugary cereal alongside four apples, three bananas, two eggs, and a grapefruit? You got the feeling the cereal wasn’t really the main contributor to the “complete” part of the meal.

When it comes to lice treatment, Listerine is much the same as Apple Jacks. It may work as “part of the complete breakfast,” but it is not the key ingredient, or even beneficial to the lice treatment diet. In much the same way the fruit and veggies end up doing most of the work to make up the complete breakfast for the sugary cereal, the lice comb bears the bulk of the responsibility for delivering results on behalf of the Listerine.

Do head lice change color?

According to the research of R. Hoeppli, ancient Chinese medicine used lice to cure “high fever and severe headaches as if the skull is cracking.” A paste made from 300 – 500 black lice, spread on the head, was said to do the trick. I must admit, I’d rather have 500 pureed lice on my head than 500 live ones, but the question this raised for me was where one would find black lice. Is there such a thing?

Head lice that I’ve seen have ranged from pale ivory through a golden – sometimes reddish – brown; magnified, they are transparent. Lice that have fed have a black mass inside – presumably blood in the process of being digested – but are not, themselves, black. There is a colour range, to be sure. But black? A literature search turned up some interesting things:

• Head lice may have a natural way of blending in without actually changing color. Ibarra and Hall wrote: “Eggs and lice are well camouflaged, reflecting the colour of their surroundings.”

• Newly hatched lice that have not fed are transparent (Meinking) and do not have color until after they’ve fed.

• Color that matches the background has been shown to have evolved in other species of lice. This, however, refers to colour change over generations, not within the life span of a single organism.

The ‘wisdom’ that human head lice change color depending on the hair color of the host is oft repeated on websites and in non-academic publications. Published scientific information to back it up, however, appears nonexistent. Similarly, parasitology texts and laboratory identification references do not mention it

I remain highly skeptical that our head lice can change color within one generation, or that black head lice actually exist. I conclude that the Chinese remedy called for human head lice that had fed and had blood in their guts..

Head Lice Prevention – is it even possible?

When we provide lice removal services in a family’s home, the nice lice experts at Larger Than Lice are always asked “How can we prevent this from happening again?”

We wish there was an easy answer.  Or at least an answer that would guarantee a person would never have to have the head lice experience again.

But the fact is that head lice are an incredibly common infliction and no-one is immune!   Lice can happen to anyone at any time, regardless of hair type, hair color, gender or household income. Lice are common in schools, in daycares, in camps – pretty well anywhere kids (or adults) gather.

How is Head Lice Spread?

Head lice spreads by direct head-to-head contact with someone who has a case. The louse crawls along the hair and simply crawls onto another person’s head via a strand of hair.  Nits, or lice eggs cannot be spread from head-to-head.  Eggs are laid on the hair shaft with a cement-like glue which keeps them securely on the hair until the bug hatches from the egg.

Head lice spread within families, especially if parents and children lie down together, sit closely or sleep together. Lice spreads easily in schools as well because young children typically have close contact with one another, either with desks set side-by-side or during normal play and school activities. Though head lice do not hop, jump, or fly, they do crawl very quickly.

A secondary way of contracting lice is through an object which could have a live bug on it. Items like hairbrushes, hair accessories, helmets, headwear and scarves should not be shared.  It’s even possible for a louse to be left behind on a movie theatre chair or train seat headrest.  Note that this is NOT the typical way to contract lice, but it is possible.

Being in the same room or taking place in an activity in which someone has a case of head lice does NOT mean you will catch a case.  There must be direct head-to-head contact with the infected head.   Activities like sleepovers are an example of where children might have this kind of direct head-to-head contact over a period of time, exposing them to the possibility of contracting head lice.

How to Prevent Head Lice

It’s not an option to home-school every child or put them in quarantine, keeping them from everyday social activities.

But there are a few methods of prevention that might reduce the risk.

Keep long hair tied up in ponytails or even better, braids or a bun. Use tea tree oil or Buzz Off Lice Repellent Hair Spray either by adding a few drops to your regular shampoo, or by making a spritz by adding a few drops to water in a spray bottle. Tea tree oil can be very drying, so only use a few drops (as directed).

• Take a peek once a week. Catch head lice early and it is easier to remove.
• Educate your kids what to do to avoid getting lice and of the symptoms like scratching.
• Don’t share hair items and visually check head rests before laying or placing your head on them.

Parents should be alert to the common sign of head lice – scratching the head.  Watch for children who are scratching or who might even wake up in the night saying that their head is itchy.  Pay attention to kids who are visiting and watch to see if they are scratching their scalps as this could indicate a case of lice.

1. Once a Week, Take a Peek

Regular checking can identify a new case early. If a case is caught early enough, the life cycle of the louse can be interrupted. No further eggs will be laid and a case can be eradicated in just a few days. The best way to screen for head lice is to lather the hair with conditioner and thoroughly comb the hair out with a head lice removal comb (Professional Lice & Nit Terminator Comb), wiping the comb on a white paper towel after a few passes. Inspect the paper towel looking for brownish-colored eggs or actual bugs.

If checking for head lice visually, be sure to use direct sunlight or a very good table lamp. Carefully inspect the hair paying particular attention to the area when the hair shaft meets the scalp.  Look around the ear, nape of the neck and especially the crown of the head, as these are common areas for lice to be found.

When checking for head lice, look for lice eggs attached securely to the hair close to the scalp. Viable eggs will be brownish in color and cannot be flicked off the hair. They have to be removed between the fingernails, with tweezers, or with a good nit comb. Though head lice move very quickly, you may see an actual bug. Lice are the size of sesame seeds and are brownish-gray to caramel in color. They are see-through and can appear to take on the color of the hair.

Preventing Lice in the Community

It takes a community to prevent head lice. Advocating for regular lice screening in the school can go a long way to preventing a head lice outbreak. If children are regularly screened, cases might be identified and therefore treated before they have a chance to spread.

Professional screening staff from Larger Than Lice can provide screening services in schools, daycares and camps. For as little as $3 per head, each child can be checked for lice. School volunteers can also be trained to identify lice so that regular screenings can easily be scheduled.

Stop the Stigma

If you or a family member does contract head lice, don’t panic. This very common condition has nothing to do with cleanliness and it can be treated without the use of pesticides. Millions of North Americans have a head lice experience every year. A whole range of treatments is available and head lice removal services also exist in many communities nationwide.