  It is widely believed that the top loop corrections to the Higgs effective
potential destabilise the electroweak (EW) vacuum and that, imposing stability,
lower bounds on the Higgs mass can be derived. With the help of a scalar-Yukawa
model, we show that this apparent instability is due to the extrapolation of
the potential into a region where it is no longer valid. Stability turns out to
be an intrinsic property of the theory (rather than an additional constraint to
be imposed on it). However, lower bounds for the Higgs mass can still be
derived with the help of a criterium dictated by the properties of the
potential itself. If the scale of new physics lies in the Tev region, sizeable
differences with the usual bounds are found. Finally, our results exclude the
alternative meta-stability scenario, according to which we might be living in a
sufficiently long lived meta-stable EW vacuum.
