Can neem oil help eliminate lice? Randomised controlled trial with and without louse combing

Background: Neem oil and wet combing with conditioner are both claimed to facilitate elimination of head louse infestation. The aim of this pilot study was to identify whether a 1% neem oil lotion showed activity itself and/or enhanced the effectiveness of combing in treating infestation. Methods: We treated 47 participants with 1% neem-based lotion on four occasions 3-4 days apart in a randomised, community based trial, analysed by intention to treat. The participants were randomly divided between two groups: One group used a grooming comb (placebo) and the other a head louse detection and removal comb (wet combing with conditioner method) to systematically comb the hair. Cure was defined as no lice on both Day 10 and Day 14. Results: The cure rates of 6/24 (25.0%) for the placebo comb group and 8/23 (34.8%) for the louse comb group were not significantly different. Conclusion: These results indicate that this formulation of neem oil was ineffective in the treatment of head louse infestations, even when accompanied by combing. Both combing methods were also ineffective, despite being implemented throughout by trained professionals.