Many women and men may turn to facial exercises or facial yoga to tighten and tone lax skin and reign in jowling, but there is not enough evidence to support these practices, a systematic review shows. Researchers from Belgium reviewed nine published studies that were conducted in South America on effects of facial muscle exercises on facial rejuvenation. Although the authors of all studies reported positive outcomes, the research team found that the quality of the available evidence was insufficient for determining the efficacy of facial exercises for aesthetic rejuvenation. "Our review shows that there is not enough evidence to conclude whether facial exercises are effective for reducing the signs of aging," says lead author John Van Borsel, Ph.D., professor of Neurolinguistics and Logopedics at Ghent University (Belgium) and Veiga de Almeida University (Rio de Janeiro) in a news release. "The existing published studies were not randomized or controlled. Most lacked blinding and only used subjective measures to assess the effectiveness of treatment. We need better studies before we can draw any conclusions about the usefulness of facial exercises."