When human compete against another, the competitors seek to achieve an advantage over their opponent, this give the reason for some athletes to take illegal substances (doping) to improve their performance, in sports doping refer to any substance foreign to the body or any physiological substance taken in an abnormal quantity or taken by an abnormal route of entry into the body with the sole purpose of increasing his/her performance in an artificial and unfair manner.<br />Doping can help athletes develop bigger and stronger muscles , in many cases, blood doping increases the amount of hemoglobin in the bloodstream. Hemoglobin is an oxygen-carrying protein in the blood. So increasing hemoglobin allows higher amounts of oxygen to reach and fuel an athlete's muscles. This can improve stamina and performance, particularly in long-distance events, such as running and cycling.<br />Athletes use doping because they need to perform their best or may be because of money, that is to say They know that winning can reap them more than a gold medal. A star athlete can earn a lot of money and a lot of fame, and athletes only have a short time to do their best work. Athletes know that training is the best path to victory, but they also get the message that some drugs and other practices can boost their efforts and give them a shortcut, even as they risk their health and their athletic careers.<br />It should be noticed that taking doping has threaten life since it cause certain disease like, aching joints, blood-clotting problems , high blood pressure , liver problems , and mood swings , moreover its use is unethical in sports since it is considered bad for sports and a form of cheating. <br />Historically speaking, the use of substance to enhance performance in sports is a long standing phenomenon and dates back to the ancient Greek, endurance athlete and cyclists are often use alcohol, cocaine, strychnine and caffeine. As such, international amateur athletics federation (IAAF) become the first international sports federation to ban the use of stimulating substances, yet there was no laboratory test available at this time to enforce this ban until the death of cyclist Tom Simpson, during the Tour de France, following the use of amphetamines which catalyzed the situation, from that time they increase their awareness to intensify efforts to fight doping in sports . In 1999, world Anti- Doping Agency (WADA) was established in which 192 countries and more than 570 sporting organizations have signed up with WADA, its aims are to promote, co-ordinate and monitor the fight against doping in sports , to protect the athletes right to compete in a doping free sports , and to promote the equality among the competitors worldwide . WADA is responsible for the World Anti-Doping Code in order to harmonize these rules in all sports and all countries. <br />To conclude, performance enhancing drugs should be banned because of its health concern, ethical concern, and legal concern., in other words, doping effect the natural talent and moral integrity of the true spirit of the sport as such it gives unfair advantage and violates the spirit of competition so, this will give wrong message to children as well as unfairly diminish the historic achievements of clean athletes. so that, the efforts to stop it should remain strong for our sports need to return to the real spirit of sport where all athletes compete on a level playing field. <br />Key words : doping, advantage and disadvantage <br />