Retinal (also known as retinaldehyde) behaves similarly to the better-known retinol but is much more stable and effective. When the body does not use vitamin A, it is stored within the skin cells as retinyl esters. Once the skin is ready to metabolize vitamin A, these esters are converted to retinol and then to retinaldehyde before ultimately becoming retinoic acid that is utilized by the skin.
That's why all variations of vitamin A, including retinol and retinal, must be converted to retinoic acid before they can take effect. Retinol must be metabolized to retinal and then to retinoic acid, whereas retinal only requires one conversion to retinoic acid. Crucially, this last step is extremely rapid compared to the previous conversions, which is why Retinal can provide such quick results (up to 11 times faster) than retinol. In addition, retinal has a much higher exfoliation rate than retinol to reduce skin roughness and increase dermal thickness, collagen strength, and new collagen fibers.
These benefits can be delivered without the skin irritation effects often accompanying retinoic acid.
