Stretch marks rank right up there with cellulite and varicose veins on many a new mother's list of woes.

The list of so-called remedies is long, too, ranging from coffee grounds to Vicks VapoRub to cocoa butter and others that do little to erase the unsightly striae, as the marks are called by doctors.

'Fifty different treatments is a dead giveaway that there isn't a front-runner that works for everyone,' says Linda K. Franks, assistant professor of dermatology at NYU Medical Center in New York and director of Gramercy Park Dermatology.

Doctors haven't figured out the exact mechanism that causes stretch marks, which appear when the skin is pulled quickly, leaving a red scar that tends to fade over time. Whatever is happening, the skin stops producing enough collagen, a protein that is vital for elasticity. A mix of hormones, weight gain and genetic disposition seems to be at play, Dr. Franks says.

She offers some tips on which treatments might be worth trying, and which ones to skip.

Most remedies work by simply moisturizing, which stimulates the skin to make more collagen. This can be achieved with olive or grapeseed oil, or a moisturizer from brands such as Neutrogena or Aveeno, says Dr. Franks. Moisturizing is most helpful before stretch marks appear. More expensive lotions, cocoa butter and shea butter tend to work in the same way, by super-hydrating the skin.

'Anything that is $200 an ounce is not worth throwing on the pregnant abdomen,' she says. 'A good moisturizer would do.'

This prescription-only medicine is best known as a treatment for acne. Using the cream can reverse the scarring of stretch marks, but early intervention is vital. Dr. Franks suggests applying it while the scars are still red. That means as soon as possible after delivery, though it shouldn't be used while the new mom is nursing.

Some laser treatments, such as the vascular lasers also used to treat varicose veins and rosacea, can erase stretch marks that are still red. The heat from the laser creates more collagen and the treatment costs about $600.

Treatments using Fraxel and CO2 lasers can erase the older white scars, says Dr. Franks, by wounding the skin and generating collagen. But these cost closer to $900 for each of several treatments, and they don't tend to be covered by insurance.

Internet searches suggest Vicks VapoRub as a treatment, but Dr. Franks had never heard of it being used. However, menthol -- an ingredient in VapoRub -- can be used as a lip plumper, suggesting it could temporarily improve the appearance of stretch marks, she says.

There are also some indications that mixing coffee grounds with oil may be effective, says Dr. Franks. Caffeine might be helpful in reducing cellulite, which also involves weakened collagen.

However, she adds, 'There's nothing quick. It all takes time to build collagen back up.'