What is the Difference Between Tretinoin and Retinoic Acid, or is There One?

Tretinoin or Retin-A is the topical form of retinoic acid. It is commonly used for acne. Tretinoin also has rejuvenative effects on the skin namely compacting the epidermis so skin looks and feels smoother, increasing collagen content so that skin has less fine lines and wrinkles, and minimizing brown spots to provide more even coloration.