  We investigate the influence of the spatial extent of the proton
magnetization and charge densities on the 2S hyperfine splitting in muonic
hydrogen. The use of a non-perturbative relativistic Dirac approach leads to
corrections of 15% to values obtained from the perturbative treatment
encapsulated by the Zemach radius, which surpass the next-leading order
contribution in the perturbation series by an order of magnitude.
