Before we dive into stretch mark creams, here's what you need to know: When you quickly increase in size, you stretch the elastin in your skin (located in the dermis) and that ultimately causes it to break down. "Think of it as pulling a rubber band," says Murad. "If you keep stretching and stretching, it doesn't come back to the same shape."

As for improving their appearance, any marks that have turned white are sadly ones you may need to learn to love. "But if stretch marks are relatively new (usually dark in color), you should see results within three months of daily application," Murad says. If the marks are white and have been around for years, that means the skin has undergone more or less permanent damage. (But remember, it happens to a lot of us.) "[At that point] I'm not sure a cream can do a lot of good, though it's worth a try," says Murad. "It may take five to six months to show results."

Now that you've gotten the lowdown on stretch marks, it's time to dive into testing stretch mark creams. Do they really work? Let's find out.

Claims: "Decreases the appearance of existing stretch marks" with the use of Darutoside (a botanical ingredient shown to help with the texture and size of stretch marks) and Registril (a combo of plant extracts shown to improve stretch marks' depth and color)

Pros: Safe for use during pregnancy and breastfeeding, contains natural and organic ingredients, free of dyes, parabens and phthalates, easy to apply, short drying time

Cons: Expensive, must be used twice daily for first month

Results: "True to this product's word, it is a 'minimizing cream,' not a 'disappearing cream.' I started using the [citrus-scented] cream a week after having my third child, and although I can't say my stretch marks are gone, I can say that their color has faded and my skin [texture] is much smoother." — Robin