Retin-A can help self-conscious teenagers get past acne and soften the wrinkles of the middleaged. Now, researchers say, it may shrink stretch marks from pregnancy or obesity.
Tretinoin, the active ingredient in Retin-A acne cream and Renova wrinkle cream, shrank stretch marks 14 percent lengthwise and 8 percent in width among 10 patients who rubbed it on daily for six months, researchers said.
Twelve people with similar stretch marks who were given a dummy cream saw their stretch marks grow an average 10 percent in length and 24 percent in width in the same period, said the researchers, led by Dr. Sewon Kang of the University of Michigan Medical Center at Ann Arbor.
The study was supported partly by Johnson & Johnson Corp., of Raritan, N.J., the parent of Ortho Pharmaceutical Corp., which makes Retin-A and Renova. But the company had no role in the study itself, the authors said.
The researchers declined to comment on their published work. “They don’t want to appear to be promoting an unapproved use,” said medical center spokeswoman Michelle Donaldson.
The subjects in the study were ages 17 to 32 and had stretch marks caused by pregnancy, obesity, weightlifting and large breasts.
All had stretch marks described as being in their “early” stages, when they were pink or violet and the skin was still smooth. Previous studies of tretinoin to treat stretch marks included subjects with older, established marks, and the results of those studies varied.
To work, tretinoin probably must be applied when the stretch marks are in their early stages, the researchers reported in the May issue of the American Medical Association’s Archives of Dermatology.