What is banned
The world Anti-Doping Agency's list of banned drugs and methods.
Doping - the rules
What is classed as doping, why it is wrong and what happens to those caught doing it.
Some examples demonstrate how complicated it can be to apply the rules about doping in sport.
Drugs in sport - public opinion
How doping stories are affecting public confidence in sport
It's good news that athletes have failed drugs tests
Denise Lewis is pleased that cheats are exposed and punished.
Cheating in sport is becoming ever harder to judge
There are many issues to deal with in trying to ensure fairness in sport - doping, technology and now gender.
Lance Armstrong's drug of choice 'doesn't work' scientists claim
When in 2012 disgraced cyclist Lance Armstrong finally confessed to the most "sophisticated, professionalised and successful" doping programme the world had ever seen, he became sport's ultimate bogeyman.