CLA or Conjugated Linoleic Acid is a natural and healthy fatty acid that is actually essential to the basic functioning of your body. It will help you burn fat and build muscle mass overtime. If use along with exercise it can also contribute to a healthy heart rate. There is no conjugated linoleic acid side effects associated to it at all except if you are allergic to the source. So make don't waste time on exercise alone use CLA to achieve the best result.