Mascara: should be changed every season (every four months). Take no chances with eye products as bacteria can cause infection.
Foundation: once a year…unless product starts to seperate; then replace immediately.
Eyeliner: once a year.
Concealer: once a year.
Eyshadow and Blush: once a year.
Lipstick: every six months unless it comes in contact with a cold sore, then pitch it and start a new one.