Can You Build Resistance To Head Lice Products?
Read the latest news on building resistance to head lice products.
Feb 21, 2026 · 4 min read
TL;DR
People don't build resistance — lice do. Insecticide-based products (permethrin) often fail because lice have evolved resistance. Silicone- and oil-based products work by suffocation, so resistance isn't an issue.
New clinical evidence on head lice products
Research shows that permethrin and similar insecticides fail in many areas due to louse resistance. It's the lice that are resistant, not the person.
Research has uncovered head lice products are failing
If a product doesn't work, switch to a silicone- or oil-based option or wet combing. These don't depend on chemicals. Check first. Clinics offer professional removal.