Sometimes they can be toxic and actually age skin in the long run by over thinning, stressing and over drying. In addition Retin A often contain warnings such as:
It is not known whether Retin-A will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medication.
It is not known whether Retin-A topical passes into breast milk or if it could harm a nursing baby. Tell your doctor if you are breast-feeding a baby.
What is the negative perception of chemically based Retin A?
