In the US alone, it’s estimated that up to 12 million children aged between three and 11 get head lice. Adults get lice too, usually after contact with their kids!
You may have heard that using hair dye can kill head lice. But is this an urban myth or a fact? And, if it’s true, what brand of hair dye kills head lice?
Read on to find out …
What are head lice?
Head lice are tiny wingless insects. They live in your head hair, feeding on the blood that they suck from your scalp.
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An adult head louse is brown and roughly the same size as a sesame seed. Louse eggs, (called nits), are white and look like flecks of dandruff in your hair.
Head lice are harmless in that they don’t carry disease. They are, however, extremely annoying and can be very tricky to get rid of.
How can you tell if you have head lice?
It’s usually pretty easy to diagnose a head lice infestation:
- The first indication that you may be carrying unwanted passengers is a tickling feeling on your scalp as if something is moving around in your hair.
- You may feel itchy too. That’s because of the reaction that the lice bites often cause as they attack you in search of a meal.
- Run your fingers over your scalp. If you can feel sore areas and tiny bumps, these could be caused by an allergic reaction to the saliva in the louse bites.
- Check for tiny red lumps around your upper neck and on your ears; these could be louse bites.
- Part your hair and look carefully in the mirror. It’s unlikely you’ll see adult lice moving around – they’re too small to be seen by the naked eye. However, you may notice tiny white specks in your hair. What you might think is dandruff could be “nits,” or louse eggs.
But you wash your hair almost every day, and you pride yourself on your personal hygiene. So, where the heck did these horrible little parasites come from?
How did you catch head lice?
Contrary to popular belief, you can still get head lice if you have scrupulously clean hair. Head lice aren’t fussy; they can make a home on any head, as long as it has hair on it, regardless of whether the hair is squeaky clean or filthy!
If you have school-age kids, they are most likely the source of your head lice infestation. That’s because young kids often make head-to-head contact during play. The lice are passed from one child to another, and then to their parents or caregivers.
Other ways that head lice can be contracted include:
- wearing items of clothing such as hats, head scarves, hair ornaments, etc. that have been worn by an infected person
- using brushes or combs that are carrying nits
- placing your head on a pillow or bed that has been in contact with someone who has head lice
Unfortunately, there’s nothing you can do to prevent head lice, other than avoiding head-to-head contact.
So, does hair dye kill hair lice?
It’s an urban myth that head lice don’t live in hair that has already been dyed. You can still pick up head lice from your kids or your partner, whether you have natural or artificially colored hair.
However, you CAN kill adult head lice if you dye your hair again. There are two chemicals in certain types of hair dye that are highly toxic to adult head lice:
When you dye your hair with a product that contains both these chemicals, you need to allow up to 40 minutes for the dye to work on your hair. That also allows ample time for the chemicals to kill the lice.
What brand of hair dye kills head lice?
Temporary hair colors, rinse-in-rinse-out colors, and semi-permanent tints do not typically contain hydrogen peroxide or ammonia so they won’t kill head lice.
For hair dyes that kill lice, look for permanent color kits.
Hydrogen peroxide is a bleach, so it’s usually hair colors in the blonde shade spectrum that contain this chemical.
Brands of hair dye that may be effective in killing head lice include:
Check the product information to be sure that the color you’ve chosen contains both ammonia and peroxide. If you’re not sure, ask your local hair salon for more advice.
So, what about nits?
Head lice eggs (nits) have a hard, protective shell, and they’re stuck to the hair shaft with a glue-like substance that makes them extremely difficult to remove. Unfortunately, the nit’s shell makes it impervious to the effects of hair dye. So, even if dying your hair kills all the adult lice, you’ll still be left with nits, stubbornly clinging to your hair.
The head louse lifecycle typically lasts for between 38 and 45 days. Nits take from one week to 12 days to mature and hatch. Once hatched, the head lice nymphs attach themselves to the scalp and feed on your blood until they’re mature enough to reproduce. The adult head lice then lay their eggs on your hair shafts, and the cycle begins again.
How to break the cycle …
There is a strategy that will get rid of your head lice.
- On day one, dye your hair, using a brand of hair dye that contains ammonia and hydrogen peroxide. Follow the dye manufacturer’s instructions and leave the dye on your hair for the recommended time. Any adult head lice should now be dead.
- To tackle any newly-hatched nymphs, dye your hair gain on the seventh day after the initial dye application.
- Finally, repeat the exercise and dye your hair again on the fourteenth day following the second application. That will take care of any remaining nits and nymphs that escaped the second dying session.
This strategy should break the cycle and get rid of the lice, but it might also damage your hair.
NEVER use hair dye on a child’s hair. Although kids do tend to be more prone to getting lice than adults, their hair is much more delicate and susceptible to damage from hair dyes that contain bleach.
If you’ve had head lice, the chances are you’ve been scratching your scalp and broken the skin. The harsh chemicals that hair dye contains can irritate broken, infected skin and may cause an allergic reaction. Also, if you suffer from existing skin conditions such as psoriasis, you should take extreme care when using hair dyes, as they can aggravate the condition.
Wrapping it up:
Certain brands and types of hair dye can kill head lice, but you will need to carry out three consecutive treatments to be sure that you’ve caught the adult lice and any nymphs that are hatching from nits that are attached to your hair shafts.
If you don’t fancy the idea of dying your hair, ask your GP or pharmacist for advice on other lice-specific products you could use instead.