Leftose has been around for over 4 decades and been prescribed by doctors. It is proven to be effective, especially for phlegm, chesty cough and sore throat.  The reclassification to a health supplement was not because of its ineffectiveness.  It was due to the fact that it is made from natural enzyme.  The effectiveness of the product is the reason Leftose have been trusted and used by doctors and well-loved by parents.