There are many prejudices and misconceptions about what this medicine does. Some still think Duromine burns fat or prevents excess calories from splitting in the body. Actually, this is not what Duromine is used for. The main advantage of this drug is the ability to suppress the appetite. Phentermine – an active ingredient from what Duromine is made of, leads to the production of norepinephrine in the brain. Norepinephrine is a neurotransmitter that helps a person feel full. Thus, the key to better understanding Duromine and what does it do lies in the biochemical reactions that this medicine produces.