As indicated earlier, phentermine is the main ingredient found in Duromine. The phentermine is responsible for working to block transmitters that can be found in the brain. It is also able to jolt the central nervous system and the brain to release chemicals that are needed to block the feelings of hunger. These chemicals include a adrenaline and dopamine and they work effectively and efficiently in stopping and suppressing the appetite. There will be no cravings or feeling of hunger as the body will no longer be receiving the messages. In Duromine, the phentermine is mixed with a resin that will result in the slow release of phentermine throughout the day. This is very effective as the effects of Duromine will be felt as the day progresses.