Retinol and retinoids are forms of vitamin A, popularly used for their ability to treat aging, acne, and hyperpigmentation. Retinol and retinol compounds, such as retinyl palmitate and retinoic acid (tretinoin), have been shown to negatively impact hormones by interfering with testosterone, estrogen, and progesterone. Retinol is not safe for pregnancy or breastfeeding.