  As a check of the first massive integrated vertex operator in the pure spinor
formalism constructed in arXiv:1802.04486, we compute the one loop 2-point
function of the stable non-BPS massive states in SO(32) heterotic string
theory. This allows us to compute the one loop renormalized mass of these
states using the pure spinor formalism. Our results are in agreement with the
corresponding results obtained by Sen using the RNS formalism. This provides an
instance of the equivalence between the RNS and the pure spinor formalism for
the massive states at loop level.
