This work shows the usefulness of assigning current-branches-bias levels, in order to improve and accelerate the sizing optimization of MOSFET-based analog integrated circuits (ICs). That way, the proposed procedure relies on the search of current branches from the associated incidence matrix by applying a recursive technique for exploring circuit graphs. The goal is focused on determining the bounds of the width/length (W/L) search space for each MOSFET before starting the sizing optimization process. As a case of study, the proposed current-branches-bias assignment (CBBA) approach is applied in the sizing optimization of the recycled folded cascode operational transconductance amplifier by applying evolutionary algorithms (EAs). From the feasible optimization results, we conclude that our proposed CBBA approach enhances and accelerates the biasing and sizing of analog ICs by EAs.