Disclosed is a fiber elasticity conserving hair relaxer composition having an alkalinity of at least pH 12 comprising a fiber elasticity conserving amount of at least one hair fiber elasticity conserving agent selected from the group consisting of poly-organosiloxanes containing, per molecule, at least one siloxyl unit substituted with at least one group having one or more of a sterically hindered piperidinyl functional group. The composition substantially ameliorates the loss of hair fiber elasticity that frequently occurs during the hair relaxing step of a process for relaxing the natural curl of hair under such strongly alkaline conditions.
