In tobacco products, there are many constituents. An highly toxic major alkaloid is found in tobacco plant: 1-methyl-2(3-pyridyl) pyrrolidine. This molecule plays a significant role in the development of human disease and carcinogenesis. Nicotine is also accused of addictive effect of smoking. Carbon dioxide has been used to remove the nicotine from tobacco leaves, allowing the production of new cigarettes with lower nicotine rate. Studies of supercritical processes on tobacco leaves have showed good results in terms of help in further studies on sub/supercritical co2 extraction of nicotine.