Shake the bottle well before use and ensure shoulders are covered with a towel. Holding the spray approximately 10cm from the hair carefully spray sufficient solution evenly over dry hair, so that the scalp and hair are fully covered and the hair is saturated. Work into the hair, spreading the solution thoroughly and evenly from the roots to tips. Ensure solution is left in the hair for at least 8 hours (It can be left in overnight if you prefer). Rinse or shampoo solution out (you will notice it comes out easily, with the dead lice). Apply again after 7 days to combat any lice which may hatch in that time.