Retin-A (tretinoin) is a form of vitamin A that helps the skin renew itself. The Retin-A and Avita brands of tretinoin are used to treat acne. The Renova brand of tretinoin is used to reduce the appearance of fine wrinkles and mottled skin discoloration, and to make rough facial skin feel smoother.Retin-A may also be used for purposes not listed in this medication guide. Retin-A can make your skin more sensitive to sunlight and sunburn may result. Use a sunscreen (minimum SPF 15) and wear protective clothing if you must be out in the sun. Avoid getting Retin-A in your eyes, mouth, and nose, or on your lips. If it does get into any of these areas, wash with water. Do not use Retin-A on sunburned, windburned, dry, chapped, irritated, or broken skin. Also avoid using this medication in wounds or on areas of eczema. Wait until these conditions have healed before using Retin-A. Slideshow: OTC Medication Use In Pregnancy: Wise or Worrisome? Use this medication for as many days as it has been prescribed for you even if you think it is not working. It may take weeks or months of use before you notice improvement in your skin. If you are using Retin-A to treat acne, your condition may get slightly worse for a short time when you first start using the medication. Call your doctor if skin irritation becomes severe or if your acne does not improve within 8 to 12 weeks.