A robust synthesis technique is devised for synergism and saturation systems, commonly known as S-systems, for controlling the steady states of the glycolysis-glycogenolysis pathway. The development of the robust biochemical network is essential owing to the fragile response to the perturbation of intrinsic and extrinsic parameters of the nominal S-system. The synthesis problem is formulated in a computationally attractive convex optimization framework. The linear matrix inequalities are framed to aim at the minimization of steady-state error, improvement of robustness, and utilization of minimum control input to the biochemical network.