Reformulation is when a fragrance company changes the original formula of a scent. The public is not made aware of this. Usually but not always, after a reformulation the scent may become altered and or weakened.

Reformulations may happen because of ingredient recalls, or a change of manufacturer. Often after a reformulation the packaging may also undergo a change. It can be a new bottle style, or sometimes very subtle like a slight rewording or placement of text.