  Many scalar field theories with attractive self-interactions support
exceptionally long-lived, spatially localized and time-periodic field
configurations called oscillons. A detailed study of their longevity is
important for understanding their applications in cosmology. In this paper, we
study gravitational effects on the decay rate and lifetime of dense oscillons,
where self-interactions are more or at least equally important compared with
gravitational interactions. As examples, we consider the $\alpha$-attractor
T-model of inflation and the axion monodromy model, where the potentials become
flatter than quadratic at large field values beyond some characteristic field
distance $F$ from the minimum. For oscillons with field amplitudes of
$\mathcal{O}(F)$ and for $F\ll 0.1 M_\mathrm{pl}$, we find that their evolution
is almost identical to cases where gravity is ignored. For $F\sim 0.1
M_\mathrm{pl}$, however, including gravitational interactions reduces the
lifetime slightly.
