  We address the issue of the reconstruction of the scalar potential of a
two-Higgs doublet model having in mind that of the MSSM.
  We first consider the general CP conserving dim-4 effective potential. To
fully reconstruct this potential, we show that even if all the Higgs masses and
their couplings to the standard model particles are measured one needs not only
to measure certain trilinear Higgs self-couplings but some of the quartic
couplings as well. We also advocate expressing the Higgs self couplings in the
mass basis. We show explicitly, that in the so-called decoupling limit, the
most easily accessible Higgs self-couplings are given in terms of the Higgs
mass while all other dependencies on the parameters of the general effective
potential are screened. This helps also easily explain how, in the
  MSSM, the largest radiative corrections which affect these self couplings are
reabsorbed by using the corrected Higgs mass. We also extend our analysis to
higher order operators in the effective Higgs potential. While the above
screening properties do not hold, we argue that these effects must be small and
may not be measured considering the foreseen poor experimental precision in the
extraction of the SUSY Higgs self-couplings.
