The authors made a point of clarifying that mouse skin is different than human skin and these ingredients may not affect human skin the same way.
They were investigating whether caffeine has an effect on the development of skin cancer and used a moisturizing cream mixed with caffeine. They found that the cream itself caused more skin cancers.
Next they tested 4 common moisturizers: Dermabase, Eucerin, Dermovan, and Vanicream, and found the mice who were treated with the moisturizers developed more, larger skin cancers faster than those who were not treated with moisturizers. The moisturizer ingredients they suspected were mineral oil and sodium lauryl sulfate.
Finally, they made a moisturizer without these ingredients and found that it did not increase skin cancer in the mice.
One large caveat to this study is that the authors also tested other moisturizers that don't have these two ingredients and those moisturizers did increase the number of skin cancers.
After reading this study, I'm not throwing away any moisturizer I have that contains mineral oil and/or sodium lauryl sulfate, and I'm certainly not going to stop using a moisturizer. I am going to watch for further studies on human skin to see if certain moisturizer ingredients have the same effect.
The active ingredient in Mederma is onion extract - not a compound you would think to put on a scar. Does Mederma live up to the advertisements? Find out more