Hebrew University Medical School, Jerusalem, Israel tested the significance of citronella as a lice medication. Head lice move easily from head to head. OBJECTIVES: To test the efficacy of a slow release citronella formulation as a repellent against the head louse. METHODS:103 children were treated with the citronella test formulation and 95 with a placebo.RESULTS: A significant difference was observed on the children treated with the test repellent. CONCLUSIONS: Use of an effective repellent could significantly lower incidence of re-infestations, which would lower expenditure on lice prevention, and the time spent on treatment and removal of the nits. Licenders repellent contail virgin olive oil and citronella to keep lice away.