Tretinoin and retinol are both derived from vitamin A. However, tretinoin requires a prescription, while retinol is available over the counter. Tretinoin is derived from retinol and is more powerful.
Retinol is not as harsh as tretinoin, so sensitive skin tends to tolerate retinol better. However, it is less potent and may take 12 weeks or more to show benefits in smoother skin with improved tone and texture and fading of fine lines and wrinkles.
Tretinoin is up to 20 times more powerful than retinol, showing results in 4-6 weeks. However, tretinoin may have more side effects, like unusual skin dryness, redness, irritation, peeling, and pain.

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