Pure TheraPro Rx Vitamin K2 is the 100% Trans form. Vitamin K2 is available in two forms: Trans and Cis. Various studies suggest the body may only utilize the Trans form of K2. Most supplement companies try to keep their raw material costs down by diluting or mixing (i.e. 50/50 mimx) of the Trans form with the less desirable and unusable Cis form. We take this supplement daily and wouldn’t if it was formulated any other way. Purity is our priority.