The short answer? No, topically applying Listerine is unlikely to kill head or body lice.
Listerine contains alcohol and essential oils like eucalyptol, menthol, and thymol, which have some antiseptic properties. Because of that, some people believe it can suffocate or kill lice.
However, using it as a treatment doesn’t guarantee results, and scientific studies haven’t shown its effectiveness for this treatment.
When you apply Listerine to your scalp, you may feel a cooling sensation, and the strong scent might seem like it’s doing something powerful. In some cases, it might temporarily stun lice.
But stunning them isn’t the same as killing them or removing all their eggs — called nits. These eggs stick tightly to hair strands and can hatch later, starting the infestation all over again.
You also face safety concerns when using Listerine this way. It’s flammable and not meant for large-scale use on your scalp, especially in children.
Covering your head with a plastic cap after applying it increases the risk of skin irritation or even chemical burns. You could also inhale fumes, which might cause breathing problems for some people.
You’re better off using treatments specifically designed for this purpose. Over-the-counter lice shampoos and prescription topicals offer safer and more effective results.