Here’s What Really Causes Stretch Marks

If you’re loading up on cocoa butter to ward off pregnancy-related stretch marks, you might want to save your money, because the truth about what causes stretch marks is not so simple. As it turns out, genetics can seriously increase your odds of getting stretch marks, according to research published in the Journal of Investigative Dermatology.

For the study, scientists from the personal genetics company 23andMe examined the DNA of 33,930 people, 4,967 of whom were women with severe pregnancy-related stretch marks. They found that mutations in or near four specific genes—ELN, SRPX, HMCN1, and TMEM18—increased the participants’ risk of stretch marks by 40 percent. Of these genes, ELN (aka elastin) was the most strongly tied to stretch marks, especially those developed during pregnancy. Elastin is the major component of elastic fibers, which help tissues stretch and retract.

See, while excess tension on the skin is the short explanation for stretch marks, some people are more prone to developing them than others, says study author Joyce Tung, Ph.D., Vice President of research at 23andMe. For instance, in the study, only 25 percent of the men reported having stretch marks, but 55 percent of the women did.

MORE: 5 Products That Actually Help Prevent Stretch Marks

“Previously, no genetic variants were known to be associated with isolated stretch marks,” says Tung, who hopes the findings will lead to more effective treatments that target elastin production.

In the meantime, talk to your doctor about these science-approved prescriptions for preventing and erasing stretch marks.

Tretinoin Cream

Retin-A’s not just for acne anymore. It, along with other tretinoin creams (think: Renova, Avita), can help reduce the appearance of stretch marks that are less than a few months old and are still pink or red. For example, in one Advances in Therapy study, new moms who applied tretinoin cream 0.1 percent every day for three months shortened their baby bump-related stretch marks by 20 percent.

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Microdermabrasion

This procedure uses a hand-held device to blow abrasive crystals onto the skin, gently removing the skin’s top-most layer and triggering the growth of new, more-elastic skin, says Mohamed L. Elsaie, M.D., a clinical fellow of dermatology, lasers, and cutaneous surgery at the University of Miami Miller School of Medicine. One 2008 study in the Journal of the Egyptian Women’s Dermatologic Society found that it only takes five microdermabrasion treatments (at a cost of about $150 each) to significantly reduce the appearance of stretch marks in more than half of patients. Even better, this therapy is one of the few that’s effective at erasing older marks, says Elsaie.

Laser Treatments

Intense light therapies stimulate collagen, elastin, and melanin production. One of the most effective options out there is intense pulsed light therapy, which is effective at treating older stretch marks, as well as fractional photothermolysis, a resurfacing laser technique that increases in the number of collagen and elastin fibers, according to a 2009 review published in the journal of the American Society for Dermatologic Surgery. While pulsated dye and 1,450 nm diode lasers are also effective, you should know that they can actually spur skin pigment changes in patients with dark complexions. Depending on the laser that’s right for your skin, sessions cost anywhere from $300 to $750 a pop (and you’ll probably need at least a few of them).

*This story was originally published on WomensHealth.

Originally published October 2013. Updated July 2017.