Why Lice Treatments Stop Working — And What Actually Does

Why Lice Treatments Stop Working — And What Actually Does

If you've tried the over-the-counter lice shampoos and the lice are still there,you're not doing it wrong. The shampoos are. For decades, permethrin — the active ingredient in products like Nix — was the standard first-line lice treatment. It worked by attacking the nervous system of lice. And it worked well, for a while.

But lice evolve. Over years of exposure, lice populations have developed genetic mutations that make them resistant to permethrin and related compounds. Researchers call these "super lice." A 2016 study published in the Journal of Medical Entomology tested lice from 30 U.S. states and found resistance mutations in 98% of tested populations — including the DC and mid-Atlantic region.

The American Academy of Pediatrics has acknowledged that permethrin 1% may no longer be reliably effective in many communities and recommends that clinicians consider alternative approaches.

So what actually works?

Heat.

Specifically, controlled warm air delivered precisely to the scalp and hair shaft.

Lice and their eggs are physically vulnerable to heat-induced dehydration. At the right temperature, the egg's protective coating breaks down and the embryo desiccates. Adult lice dehydrate rapidly. This is a physical mechanism — lice cannot develop resistance to it the way they can to chemicals.

Two Nice Lice Ladies uses FloSonix heat-activated technology to treat DC area families in their homes. One visit. No chemicals. No repeat appointments.

If OTC treatments have already failed your family, call or text us at 202.540.0750.

We can often be there the same day.