In this paper Modified gravity is studied over the weak field linearized metric perturbation in post-Minkowskian theory. This is a different aspect for studying the two body dynamics or binary system. Here despite of usual self force originated from the radiative backscattering of gravitational waves we are considering new paradigm of perturbation that is multiplicative approach. The new perturbed metric is determined over the multiplication of isolated background metric of curved space-time for two different massive sources in post-Newtonian theory. To verify the model and the theoretical result the binary system of Milky Way central super massive black hole to Sun is considered. The computation shows remarkable result without MOND for galactic flat rotation curve and solar rotational speed 249km/sec, obviously very good agreement with recent observed data.