We study the spectral minimum and Lifshitz tails for continuum random Schrödinger operators of the form urn:x-wiley:0025584X:media:mana201300160:mana201300160-math-0001where V0 is the periodic potential, are i.i.d random variables and u is the sign‐indefinite impurity potential. Recently, this model has been proven to exhibit Lifshitz tails near the bottom of the spectrum under the small support assumption of u and the reflection symmetry assumption of V0 and u. We here drop the reflection symmetry assumption of V0 and u. We first give characterizations of the bottom of the spectrum. Then, we show the existence of Lifshitz tails in the regime where the characterization of the bottom of the spectrum is explicit. In particular, this regime covers the reflection symmetry case.