Beauty Quickie: Mascara and liquid eyeliner should be laid to rest after 3-4 months. Nevertheless, your entire makeup collection should be cleaned out at least once a year to remove any old products. Bacteria could be lurking in older cosmetic products and need to be thrown out. Even if there is some product left in the bottles, tubes or compacts it is better to just say goodbye. Skin irritation or breakouts are just not worth the risk.