Real Simple answers your questions.

By Real Simple
Updated March 04, 2009

Q. How long can you keep a bottle of body lotion or moisturizer?
Ashley Marcelle
Spring, Texas

A. Most skin-care products, even those with natural ingredients, contain preservatives to keep them fresher longer. “But like anything in nature, even preservatives lose their optimal function over time," says Fran E. Cook-Bolden, a New York City dermatologist. When it comes to body moisturizer, throw away unfinished containers that have been open for more than two years. (If you’re using a lotion on a regular basis, though, odds are you’ll need to replenish it before it expires.) An expired lotion doesn’t hurt or damage skin, but the product won’t lock in moisture or hydrate as thoroughly. Sealed and unopened bottles should be good for three years.

If, however, you notice changes in your moisturizer’s smell or texture before the two- or three-year mark, toss it. The more active ingredients a lotion contains (like SPF) and the more bacteria introduced (as when you put your fingers into a jar), the less stable the lotion will be and the more quickly it will expire. Check the product’s back label to find out how many active ingredients there are. Also, opt for pumps or tubes, which keep germs out effectively, over screw-top tubs that your fingers have to reach into. Finally, if you’re not storing the lotion in a cool spot (about 10 degrees lower than normal room temperature), the lotion will probably spoil faster than usual.
― Sarah Smith