Leading researchers have suggested that CLA's body-composition-altering effects are likely due to its ability to regulate the metabolism of fat through a fairly complex process having to do with our body’s enzymes (namely, lipoprotein lipase and hormone-sensitive lipase). More simply, CLA appears to block fat uptake and then increase the speed of fat burning.

Various scientific research studies have confirmed that CLA supplementation results in (to varying degrees) weight reduction, giving it the scientific backing that’s often called into question with supplement effectiveness.
 
When leading CLA researcher Michael W. Pariza from the University of Wisconsin-Madison was asked, "How does CLA work?" he replied, "In a general sense, what it's doing is keeping little fat cells from getting big... perhaps by blocking certain enzymes that let fat cells swell."

Pariza's research did not find weight loss in his group of 71 overweight people, but what he did find was that when the dieters stopped dieting, and gained back weight, those taking CLA "were more likely to gain muscle and not fat.'' In a separate study conducted at Purdue University in Indiana, CLA was found to improve insulin levels in about two-thirds of diabetic patients, and moderately reduced the blood glucose level and triglyceride levels.

It’s important to know that CLA alone will not help you lose weight, well not significantly anyway. CLA is most effective when taken as a supplement while following a balanced, reduced-calorie diet and with regular exercise, especially the incorporation of weight bearing activities.

CLA has been the subject of a variety of research in the past several years, and findings also suggest that some of the other benefits of CLA include the following:
• Improves metabolic rate
• Decreases abdominal fat
• Enhances muscle growth
• Lowers cholesterol and triglycerides    
• Lowers insulin resistance
• Reduces food-induced allergic reactions
• Enhances immune system

Most researchers agree that 3000 mg divided into three dosages per day with meals is necessary for fat reduction. Recent studies have also shown that 3000–6000mg  of CLA divided into three dosages per day with meals has been shown to help induce muscle-tissue growth.

USN offers three variations of CLA: