4. Mascara continued...
Some new mascaras promise to deliver thicker, longer lashes and also to stimulate lash growth with so-called lash-enhancing botanicals and other ingredients. That claim is a stretch, says Wilson. "For lash enhancers to work, they need to be applied to the base of your lashes, not the actual lashes themselves," she says. "Unless you're lining your eyes with mascara, you should purchase a lash-enhancing product separately."
When to ditch it:
Protect the health of your eyes by replacing your mascara every four months, Friedman says.
5. Eye Shadow
What's in it:
Whether you're doing a full-on Kim Kardashian smoky eye or simply sweeping a veil of taupe along your lids, the eye shadow you apply will likely contain talc and mica, both fillers, as the two main ingredients. Binders, such as zinc stearate or kaolin clay, hold the formula together and help the shadow stick to your skin. Ingredients such as bismuth oxychloride and dimethicone also improve "slip" and adhesion, so the powder glides over your skin and stays where you put it. Iron oxides, which show up on labels as Colour Index 77510 or Blue 1 Lake, are what give shadows their hue.
Cream shadows add waxes and oils to the base. Shadows in stick form are the trickiest, Wilson says. "You don't want shadow to crumble as you apply it, but you also want to eliminate drag," she says, "so it's extremely important to have the right balance of waxes, binders, pigment, and emollients."
Line the lower eye?
"Women wonder whether they should skip lower eye liner because they've heard it can make their eyes look smaller or accentuate under-eye darkness," Ahnert says. The solution: Line your lower eyelid with powder eye shadow in a lighter shade than you use on your upper eyelid.
When to ditch it:
Pressed-powder eye shadow can last two years, Friedman says. Cream or stick varieties should be tossed after six months. But if you have highly sensitive skin, it's a good idea to replace all your makeup products every three to four months, he says.