No evidence shows using vinegar for lice removal is effective. The basis for using vinegar for lice treatments comes from the idea that the acetic acid contained in vinegar will kill adult lice and dissolve the bond between lice eggs—called nits —and hair. Mayonnaise, olive oil and petroleum jelly are other types of home remedy treatments that have been shown to be as ineffective as vinegar for lice. Even treatments designed to kill lice are not 100-percent effective in removing after the first treatment. Locating lice and using proper treatment methods will kill off and cure head lice.
Routine inspections of a child's hair are the first step in finding head lice before they lead to a full-blown infestation. The nits often adhere to the hair within 1/2 inch (.0127) of the child's scalp and are difficult to remove without pulling the hair from the scalp. Adult lice remain close to the scalp and climb hairs to attach nits to hair. Combining an insecticide treatment with a lice comb pulls nits from hair and kills the adult lice feeding on the scalp.
Permethrin is an over-the-counter shampoo designed to kill lice if used correctly. Malathion is a lotion available by prescription that is applied to the scalp to kill adult lice. Kwell® is a shampoo that is only available by a prescription and also will kill adult lice when applied per the manufacturer's instructions. Hair-Clean-1-2-3® combines natural ingredients in a shampoo that is being tested for its effectiveness in treating lice. All lice treatments require multiple applications to kill hatched nits, which are resistant to the insecticides contained in the treatments, and to ensure all nits are gone by combing with a lice comb.
Combining insecticides and vinegar for lice treatment does not increase the effectiveness of the insecticide. Using more than one treatment option to kill lice is common as some strains of lice are immune to one or more treatments. All lice and nits must be killed to ensure a lice infestation does not return. Returning lice infestations are often harder to kill, as the lice remaining on the scalp will have a higher tolerance to treatments. This increases the need to be thorough when killing an initial lice infestation on the scalp.