  We examine the effects of relic dark matter annihilations on big bang
nucleosynthesis (BBN). The magnitude of these effects have scale simply with
the dark matter mass and annihilation cross-section, which we derive. Estimates
based on these scaling behaviors indicate that BBN severely constrains hadronic
and radiative dark matter annihilation channels in the previously unconsidered
dark matter mass region MeV $\lesssim m_{\chi} \lesssim 10$ GeV. Interestingly,
we find that BBN constraints on hadronic annihilation channels are competitive
with similar bounds derived from the cosmic microwave background.
