The in vivo and in situ mechanical characterization of living soft tissue presents challenges, even for properties as Young’s modulus. The VLASTIC method, based on succion, has been developed to evaluate elasticity moduli of bilayered soft tissue structures using only surface measurements. Measurements are performed with various aspiration diameters to load the material at different depths. This provides information to evaluate the upper and lower material’s Young moduli. This method is applied here to evaluate in vivo the human skin and fat Young’s moduli of human abdomen. In particular, this work challenges the method repeatability and capacity to provide patient specific mechanical properties.