  We computed flat rotation curves from scalar-tensor theories in their weak
field limit. Our model, by construction, fits a flat rotation profile for
velocities of stars. As a result, the form of the scalar field potential and DM
distribution in a galaxy are determined. By taking into account the constraints
for the fundamental parameters of the theory $(\lambda, \alpha)$, it is
possible to obtain analytical results for the density profiles. For positive
and negative values of $\alpha$, the DM matter profile is as cuspy as NFW's.
