Olay Regenerist Daily Regenerating Serum
"There's some good evidence that peptides can trigger your skin to create more of the collagen that makes skin taut and smooth," says dermatologist Jeffrey Benabio, MD, of Kaiser Permanente in San Diego. "This serum contains a peptide that's also found in far more expensive brands." Use it in the morning under makeup or at night under a richer moisturizer.

$19, drugstores

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