A slimmed-down Oprah Winfrey unveils her painting at the National Portrait Gallery in Washington, D.C. as mystery around her weight loss continues. Winfrey revealed that she’s on a weight loss drug that she would not identify. Winfrey says she went on the medication after hosting a show about weight loss. Her revelation comes as poison control announces a startling 1,500 percent spike in calls related to injected weight loss drugs.