The active ingredient in most lice shampoos is a chemical compound called pediculicide. Pediculicides are specifically formulated to kill lice and their eggs (nits) and are the key component responsible for the effectiveness of lice treatment products. There are several types of pediculicides commonly used in hair lice shampoo, each with its own mechanism of action and level of effectiveness.
Permethrin:
Permethrin is one of the most widely used pediculicides and is found in many over-the-counter lice treatment products. It belongs to a class of chemicals known as pyrethroids, which are synthetic derivatives of pyrethrins, natural compounds found in certain chrysanthemum flowers. Permethrin works by disrupting the nervous system of lice, causing paralysis and eventual death. It is generally considered safe for use on humans but should be used with caution in individuals with known sensitivities or allergies.
Pyrethrin:
Pyrethrin is a natural insecticide derived from the chrysanthemum flower and is commonly used in lice shampoos and treatments. Like permethrin, pyrethrin works by targeting the nervous system of lice, leading to paralysis and death. Pyrethrin is generally considered safe and well-tolerated, but individuals with allergies to chrysanthemum flowers or other related plants should exercise caution when using products containing pyrethrin.
Dimethicone:
Dimethicone is a non-toxic, silicone-based compound that suffocates lice by coating their bodies and blocking their breathing pores. Unlike permethrin and pyrethrin, which kill lice through neurotoxic effects, dimethicone works by physically immobilizing lice and preventing them from breathing. Dimethicone is considered safe for use on humans and is often used as an alternative treatment for individuals who may be sensitive to chemical pediculicides.
Benzyl alcohol:
Benzyl alcohol is a topical medication that is sometimes used in prescription-strength lice treatments. It works by suffocating lice and disrupting their respiratory system, leading to death. Benzyl alcohol is generally well-tolerated but may cause skin irritation or allergic reactions in some individuals.
Malathion:
Malathion is an organophosphate insecticide that is occasionally used in prescription-strength lice treatments. It works by inhibiting the activity of enzymes essential for nerve function in lice, leading to paralysis and death. Malathion is considered effective against lice but is associated with a higher risk of toxicity and adverse effects compared to other pediculicides.