More and more a big portion of all electrical power is transported and distributed through a power electronics converter, which comprises invariably magnetic components. In most cases, such components are made with Ferrites which introduce a certain amount of losses and weight/volume to the system. In addition, there is a need for outstanding magnetic components with low-loss and high dense properties able to work under the specifications that novel Wide Bandgap semiconductors demand: high frequency operation, fast transients, compactness, etc. However, there is not a clear ground about how magnetics components operate at high frequencies and under the influence of these semiconductors. Then, magnetic characterization of ferrites under distinct conditions is essential to understand the operation of these components, especially in the MHz order. Harmonic content, introduced by the switching of the fast semiconductors, and fast transients raise higher challenges for an accurate identification of the magnetic properties. Therefore, having a complete understanding of how these harmonic contents affect the operation of the magnetic components could be beneficial for improving the material selection and design procedures themselves. This paper studies the effect of Gallium Nitride inverter conditions (deadtime, fast transients, fundamental frequencies, etc.) on iron loss characterization procedures of Ferrite materials.