Dr. Barbara Sturm Clarifying Serum Clarifying Serum, an important component of the Clarifying Line regimen, contains a powerful blend of soothing ingredients and antioxidant actives that will nourish and protect your skin. Albatrellus Ovinus extract and Purslane calm the skin and reduce the visible signs of irritation, resulting in a more even complexion. The serum delivers Hyaluronic Acid to hydrate the skin and reduce the appearance of fine lines and wrinkles.