Retin-A improves the cosmetic appearance of the skin, but it also helps treat some functional problems of the skin such as acne and mottled colouring. The earliest effect of Retin-A is that the outer layer of keratinocytes start shedding off, leaving the skin fresher, smoother and more evenly pigmented. The next effect seen is that the epidermal cells start to replicate faster causing the skin to look and feel softer, more robust and healthier. Finally, the collagen bundles in the dermis will thicken and organize, causing the appearance of fine lines and wrinkles to lessen with time. Typical treatment regimens include a period of tapering up. The topical product is applied sparingly 2-3 nights per week for several weeks and then the frequency is gradually increased until a nightly regimen is attained. Do not apply to eyelids, corners of the nose and mouth.