List of products in the National Drug Code with proprietary name . This medication is used to reduce excess fat in the stomach area (abdomen) in people with HIV infection who have changes in the way their body fat is distributed. Some HIV drugs may cause this side effect (increased fat in the upper back and stomach areas, decreased fat in the arms and legs). Tesamorelin works by causing your body to make more growth hormone. This medication should not be used for weight loss.