Full marks head lice solution is a simple treatment that takes approximately 10 minutes to work and is clinically proven to kill head lice quickly why use full marks head lice solution contains cyclomethicone isopropyl myristate which cause the lice to to die through dehydration eliminates eggs fine metal tooth comb included in the pack low odour no traditional pesticides suitable from 2 years and over including those with asthma and sensitive skin