Dermalogica products are designed to be most efficacious when prescribed by a Dermalogica professional skin therapist extensively trained in Face Mappingskin analysis. Face Mappinganalysis is the process of analysing your skin, zone-by-zone, to diagnose your skin condition and prescribe subsequent products for results. Without the assistance of a Dermalogica professional skin therapist, you may select the wrong products for your skin, and fail to reach your desired skin health results. Dermalogica stands behind the efficacy of every product we sell, if you have purchased it from an authorised location. Unauthorised locations, including many internet selling sites, may sell counterfeit and outdated products, and should be avoided as we do not guarantee their authenticity.