  We employ the graviton self-energy induced by a massless, minimally coupled
(MMC) scalar on de Sitter background to compute the quantum corrections to the
gravitational potentials of a static point particle with a mass $M$. The
Schwinger-Keldysh formalism is used to derive real and causal effective field
equations. When evaluated at the one-loop order, the gravitational potentials
exhibit a secular decrease in the observed gravitational coupling $G$. This can
also be interpreted as a (time dependent) anti-screening of the mass $M$.
