Timber-to-timber connections are vital for the structural integrity of mass timber systems, especially in sustainable construction practices that avoid adhesives and metal fasteners. However, design codes offer limited guidance for wooden dowel connections, particularly regarding their load-carrying capacity. This study assesses the mechanical performance of timber connections assembled with wooden dowels through experimental testing, analytical formulas, and probabilistic modelling. It explores different lamellae materials (Pinus taeda and Eucalyptus grandis), dowels (Eucalyptus grandis, Eucalyptus tereticornis, and Balfourodendron riedelianum), and diameters (15, 18, and 20 mm). Experiments focused on measuring load capacity and failure modes in double shear connections, comparing results with Eurocode 5 and the Timber Frame Engineering Council (TFEC) predictions. Eurocode 5 generally overestimates capacity, while TFEC aligns more closely with experimental data, especially for dowel-related failures. Calculations followed standards for deterministic values, and Monte Carlo simulations accounted for material variability. The experimental analysis identified failure modes aligned with Mode IV of Eurocode 5, Mode V of TFEC, and mixed behavior. These findings support the development of adhesive and metal-free timber connections, in particular where the combination of material may lead to different failure modes.