Source: A randomized, controlled comparative study of the wrinkle reduction benefits of a cosmetic niacinamide/peptide/retinyl propionate product regimen vs. a prescription 0.02% tretinoin product regimen (The British Journal of Dermatology - Mar, 2010)
If your skin gets irritated, you should stop using tretinoin immediately
It's important to be patient with any irritation you have when starting your tretinoin journey. A little bit of skin irritation is all part of the process, so you don't worry if your skin becomes slightly dry, flaky, or red when you first introduce tretinoin into your skincare routine. However, if your skin is really uncomfortable and super-dry, speak to your dermatologist about switching to a weaker, less concentrated tretinoin dosage. Pain is never a good thing.
You don't need to use tretinoin until you have wrinkles
Dermatologists actually recommend adding an active ingredient such as tretinoin into your skincare routine once you hit 30 to prevent the visible signs of aging. Plus, even if you don't have wrinkles yet, tretinoin will help reduce the sun damage you may have gotten over the years and will prevent wrinkles and dark spots.
: Tretinoin will make your rosacea worse
It's not a good idea to use tretinoin in the midst of a rosacea outbreak. Otherwise, however, you shouldn't have any additional redness after the first couple weeks of use. And, in fact, studies have found that tretinoin might even be a treatment for rosacea.