Structural thermosetting adhesives, such as rubber-toughened epoxy resins, are indispensable in modern engineering, due to their high strength and stiffness, excellent adhesion to diverse substrates, and high chemical resistance. To ensure long-term durability and safety of structural bonding applications, it is essential to properly dimension the adhesive joint for the intended service life and conditions. Numerical modeling enables prediction of the adhesive layer’s mechanical response under various loading conditions and design parameters, thereby supporting joint optimization and guiding the experimental studies to target only critical cases. However, capturing the complex behavior of the bulk material remains a significant challenge. This work proposes a novel finite-strain hyperelastic-viscoplastic constitutive model utilizing implicit gradient-enhanced damage. A compressible Neo-Hookean hyperelastic framework using the Pence-Gou potential is employed to ensure thermodynamic consistency. Utilizing the phenomenological framework of Balieu et al. [1], the inelastic behavior incorporates non-associative Perzyna-type viscoplasticity governed by the Raghava yield criterion. The plastic potential is formulated to allow for an independent evolution of the viscoplastic flow direction under tensile and compressive hydrostatic stress states. This enables the model to distinguish between rubber particle cavitation-induced volume expansion in tension and matrix shearing in compression. To resolve pathological mesh dependency during strain softening, an implicit gradient-enhanced damage formulation is introduced. The model is efficiently implemented in a finite element framework and validated against experimental data, demonstrating robust predictive capabilities. [1] R. Balieu, F. Lauro, B. Bennani, R. Delille, T. Matsumoto, E. Mottola. A fully coupled elastoviscoplastic damage model at finite strains for mineral filled semi-crystalline polymer. International Journal of Plasticity, Vol. 51, pp. 241-270, 2013.