The effect of a topically-applied cosmetic oil formulation on striae distensae

Background: Stretch marks or striae distensae are tears in the dermis, above which the epidermis remains intact. Striae result from rapid expansion of the underlying tissue, e.g. during puberty, pregnancy or rapid weight gain. The prevalence of striae is high (up to 80% in most populations). Many of the successful treatment modalities for striae (laser, surgery, prescription-only medication) entail high costs, often with the involvement of private medical practitioners. The objective of the study was to investigate the effect of a topical application (Bio-Oil™) on striae in 20 healthy Caucasian women. The study was performed according to standard good clinical practice guidelines. Methods: The study was conducted among 20 healthy Caucasian women with bilateral abdominal striae. The women used the test product on one side of their abdomen twice a day for 12 weeks, and their normal moisturising routine on the other side. Assessment methods were: 1) subjective visual self-assessment, using both the Patient and Observer Scar Assessment Scale (POSAS) and a directed difference (i.e. comparison of sides), and 2) objective laboratory visual assessment (blinded) using the same scales. Results: The subjective visual self-assessment yielded statistical significance at four weeks in terms of improvement of the treated striae when compared to the untreated sites, using both the POSAS and directed difference. Objective laboratory visual assessment, using the POSAS and directed difference, showed a statistical improvement on the treated side from week 2 onwards. Conclusions: The test product (Bio-Oil™) significantly improved the appearance of striae on the treated side of the abdomen as assessed by both subjective and objective assessments. This study has shown that it is possible to improve the appearance of striae with the topical application of a relatively low-cost, non-medicinal product.