It was originally researched for the treatment of Alzheimer's disease and Parkinson's Disease, but was subsequently dropped from development for these applications after early trial results showed limited efficacy for treatment of Parkinson's,[1][2] but significant weight loss in trial participants who were obese.[3] It is now being researched for the treatment of obesity, acting both as an appetite suppressant and also stimulating resting metabolic rate.[4] As of 2006 it was in Phase II trials for the treatment of obesity, and Phase III trials are currently underway.[5] Sustained treatment with tesofensine has also been shown to increase BDNF levels in the brain, and may possibly have an antidepressant effect.[6]