Soothing Agent Best Antioxidant Soothing Anti-Ageing Soothing Agent opis Any ingredient that soothes and improves signs of sensitivity. Interestingly, most antioxidants function as soothing ingredients because one of the skin’s responses to environmental damage is sensitivity, visible signs of stress on skin’s surface, and redness. These ingredients go a long way toward helping the skin deal with its daily struggle against environmental damage and seasonal environmental extremes.