Low poo refers to a shampoo that contains no sulphates or silicones. Sulphates (often labelled as Sodium Laureth Sulphate or SLS) are the ingredients in shampoo that provide lather and bubbles. Remove the sulphates and you get a low foaming shampoo. Silicones coat the hair, initially giving the allusion of shiny hair but over time these silicones can build up and leave the hair dull and lacklustre