Concrete is strong in compression andweak in tension,which results in a lowtoughness and ductility in plain concretemembers under flexure. The traditional solution is to use steel reinforcement bars, but other solutions can include the use of distributed fibers in the concrete mix. To transition to a bio-based circular economy, natural fibers such as abaca and coconut are currently being explored. Proper design requires understanding their tensile behavior under flexural loading. Experiments on concrete prisms with natural fibers under third-point loading have been carried out. These are compared and fitted with an analytical moment-curvature response incorporating a quad-linear tension model, enabling strain compatibility analysis for structural design. While experiments on larger scale and on reinforced concrete members have not been carried out yet, the current results provide a foundation for the analytical modelling of members with natural fibers in bending.