I recently did some research since I was hearing people state different shelf life for basic makeup products. I did this a few nights ago before I went through my makeup kit and started throwing out the old and making a list to restock it with new products, which i religiously do the last week of every month. Here is a basic guide of expected life span of your makeup cosmetics and a few things to watch out for! The reason you should do it is to prevent, unwanted break outs, and skin or eye infections.
MASCARA- Should last up to 2 months or when the label is warn off, it clumps, specks, becomes dry, or smells bad.
FOUNDATION- Lasts 18-24 months, throw away if it smells bad or if cream foundation separates.
POWDER- Lasts up to 2 years unless it becomes dry, or has an odor other than its original fragrance.
LIP PENCILS- Up to 1 year- always sharpen or dip in alcohol to kill germs after each use.
EYE PENCILS- Up to typically 3 months- always sharpen or dip in alcohol to kill germs after each use.
EYE SHADOWS & BLUSH- Lasts the longest, throw away if it has become too dry or has lost its pigment.
BRUSHES- When your brushes start to look like fans & the tips begin to stain a different color its time for new brushes. Keep brushes clean with brush cleaner and 90% alcohol. Wash your brushes with conditioner once a month and let air dry.
* To make sure your products are up to date place a small piece of tape on back of the containers and record the date purchased on it.