  The apparent missing mass in galaxies and galaxy clusters, commonly viewed as
evidence for dark matter, could possibly originate from gradients in the
gravitational coupling parameter, $G$, and active gravitational mass,
$M_{act}$, rather than hypothetical beyond-the-standard-model particles. We
argue that in (the weak field limit of) a Weyl-invariant extension of General
Relativity, one can simply affect the change $\Phi_{b}(x)\rightarrow\Phi_{b}(x)
+ \Phi_{DM}(x)$, where $\Phi_{b}$ is the baryon-sourced potential and
$\Phi_{DM}$ is the `excess' potential. This is compensated by gradients of
$GM_{act}$ and a fractional increase of $O(-4\Phi_{DM}(x))$ in the baryon
density, well below current detection thresholds on all relevant scales.
