Ferulic acid for skin with signs of premature aging, is an ingredient to be favored, as products with this ingredient will firm the skin and brighten the complexion. It is an organic acid naturally present in certain fruits and vegetables such as spinach and rhubarb. It is found in different types of products such as serums, lotions and creams. At what time of the day should I use a ferulic acid care? How often, and how long can I use it?