Stretch marks affect anywhere from 50 to 90 percent of women, some of whom are at a higher risk than others due to reasons such as family history.
Frank Wang, M.D., an assistant professor and dermatologist at the University of Michigan Health System, believes that very few to none of the products currently available for stretch marks actually work. In order to find a solution that is truly effective, his team analyzed the cause of stretch marks at the molecular level by narrowing in on the dermal elastic fiber network. This network provides the skin with its elastic properties. Wang and his team evaluated skin samples from 27 pregnant women who had stretch marks that were recently formed and compared them to older stretched skin on the abdomen and the hip. The fiber network was examined by immunofluorescent staining, while gene expression was measured by real-time polymerase chain reactions.
Wang and his team discovered that the elastic fiber network in the dermis gets disrupted in a stretch mark and continues to remain that way. Although the skin does try to repair the disruption, it does not appear to be effective, which is why many older stretch marks appear slack and loose. Wang believes that it "make[s] more sense to focus on preserving the elastic fibers you have rather than repairing damaged ones within stretch marks. Regardless, it's more complicated than just rubbing something on your stomach."
McDougall, A. (2015, November 24). More research needed into stretch mark causes before any treatment can be effective.