Nit-removal preparations do not work — official

Louse eggs glued to hair strands

I am a geek, so my light reading often extends to the scientific journal Medical and Veterinary Entomology, published for the Royal Entomological Society. And I take great delight in bringing you the latest nit news from the arcane world of academic entomology.

Phthirapterists (people who study lice) are an inventive bunch. Not only do they keep lice as pets (more on that later), they build nit-testing machinery. The latest offering is a gadget to test how easy (or not) it is to slide a nit from its cemented position on a hair stalk.

Nit glue is pretty tough stuff, and is one of the secrets of louse success. It is created by the female louse as a liquid, but hardens within seconds on exposure to air. It forms a tight sheath around the hair stalk which holds he egg in place with a vice-like grip. Long after the tiny louseling has hatched and walked off across the scalp, the empty eggshell (nit), now bright white, is a brilliant distraction to focus our grooming on the wrong things. Months after the louse has left its egg, the nits are still firmly attached to the hair, and as the hair grows the nits just become more obvious.

Since some schools operate a no-nit policy, parents can spend hours of wasteful time trying to get rid of them. Any pharmaceutical company that comes out with a nit-glue-dissolving preparation will be on to a winner. But I’m not convinced. The cement appears to have a chemical structure somewhat similar to hair. If a chemical can dissolve the glue, surely it will surely dissolve the hair too. The trouble is that these chemical companies can get rather carried away with the advertising claims.

Ian Burgess, at the Medical Entomology Centre in Cambridge, put some of their claims to the test. He developed a machine with a tiny glass tube through which a nit-laden hair was passed. The tube was so small that the hair could just get through, but the nit could not, and was held fast at the tube entrance. He then measured how much force was required to pull the hair through the tube, and free from the louse egg.

He tried several specialized nit-loosening brands, along with some anti-louse shampoos, ordinary hair conditioner, olive oil, plain water and dry hair. And this is what he found:

“We conclude that so-called ‘nit-removing’ products have no effect in terms of loosening the grip of the cement-like fixative secreted by the female louse to hold her eggs in place on the hair. None of the products tested demonstrated any detectable chemical or physical activity beyond lubricating effects indistinguishable from those found for widely used toiletry or cosmetic products….There appears to be no justification in purchasing products specifically marketed for this purpose.”

In other words, they don’t work. Told you so.

9 responses to “Nit-removal preparations do not work — official

    • Jessica, the ‘nit’ (egg) removal compounds do not remove the eggs from the hair shafts, but since the eggs are soon empty this does not matter. The key is live louse removal, using fine-toothed nit-combs. Repeated every few days, this gets rid of the louse population and without lice, no more eggs will be laid. Good luck.

  1. it’s so clever that their glue is similar to hair. it’s also frustrating. the eggs get looser over time, and sometimes fall off, so is their any substance tested that ages the glue quickly so that they fall?

    • Debra, I’m afraid the idea of dunking your head in vinegar is another myth that needs debunking. The glue is protein. If something dissolved it, it would probably dissolve your hair, or your head, too.

  2. I’ve been shampooing to kill lice for a few weeks now on my daughter, and trying my damnedest to get out the many many nits and eggs. Fortunately I have not seen any live lice since my first go-round with the shampoo and comb… but she has SO MANY nits/eggs left and they are all too small and slip right through the comb. So the only option I know if is to pick nit-by-nit-hair-by-hair, and that is taking hours and hours… IS there a good comb that won’t allow the nits to slide through the comb teeth? I already don’t buy into the home-remedies myths… I just want science to make something that works for nits.. I’m going crazy.

    • Nit Free Terminator Lice comb which you can buy from Walmart works amazingly well… Gets out all the nits… Just keep combing and wiping on a paper tower about three comb thrus…Do this in sections… I just got out about 500 nits out of my granddaughters hair and was taught this by a lady that came out to do it at my house… Comb cost 9.99 from Walmart… Wet hair with a spray bottle with some conditioner in it so the hair is easy to comb… Not soaking wet just wet… And go at it

  3. Thank you for your inform and sincerity.I have been suffering for head lices for a year.I have tried everything at the counter and nothing is working.
    I am really desperate because I have terrible allegy to these bugs.
    This reports just confirm what I was thinking nothing works.

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