Number of stripped medals at the Summer Olympics per country and by color 1968-2020

A total of 133 Olympic medals (42 gold, 43 silver and 48 bronze) have been retroactively stripped from athletes for a variety of offences at the Summer Games. Most* of these offences were related to doping, usually where banned substances were found in urine samples, but also where athletes tampered with these samples or failed to provide a valid sample on time (and a small number of non-doping related offences). The death of Danish cyclist Knud Enemark Jensen during the Team Time Trial in 1960 led to the formation of an Olympic medical committee in 1961; this committee then introduced drug testing at the Summer Olympics in 1968. The first athlete to have a medal rescinded as a result of these tests was Hans-Gunnar Liljenwall in 1968; the Swede had two beers to calm his nerves before a shooting event, but had inadvertently consumed an illegal amount of alcohol. Since then, a number of other athletes (or their horses) have accidentally or unknowingly taken banned substances, but evidence suggests that a great deal more have done so intentionally. The first high-profile athlete to be stripped of their medal was Canada's Ben Johnson, following his victory in the 100m sprint in 1988. The scandal rocked the world of sport, was covered heavily by international news outlets, and increased public awareness of the use of steroids in top-level sports.

BALCO and Team USA in 2000

Athletes representing the U.S. have been stripped of ten medals in total, with seven of these coming in the 2000 Games in Sydney; five of these were from one athlete. A 2002 federal investigation into the Bay Area Laboratory Co-operative found that the lab was providing many professional and Olympic athletes with prohibited substances. When investigators were anonymously provided with a syringe containing unknown substances, this allowed them to trace the materials back to other athletes' samples, who were speedily implicated and charged. The anonymous whistleblower turned out to be the running coach of Marion Jones, who took gold in the 100m, 200m, and 4x400m, and bronze in the Long Jump and 4x100m in Sydney. The investigation did not immediately incriminate Jones, further testing led to her admission of guilt in 2007, and she subsequently turned over her five Olympic medals. Although Jones had won two of her medals in team events, her co-competitors had their medals restored to them in 2010 as the rules in 2000 did not punish teams for the actions of one member. This ruling also benefitted the men's 4x400 team, who had been stripped of their medals in 2004 for the actions of one of the runners in the heats and semi-finals. The men's team's records and medals were restored the following year, but the team was then re-stripped of their medals in 2008 when another member (who ran in the final) also admitted to doping. The seventh medal was stripped from Lance Armstrong, who won the bronze in Individual Time Trial; Armstrong returned his medal in 2013, following the development of the largest doping scandal relating to any individual athlete.

Russian doping scandal

While the Soviet Union and Eastern European states had a history of state-sponsored doping programs throughout the 1970s and 1980s, their doping methods were usually one step ahead of the testing methods, and were difficult to prove (in the past twenty years these countries have had more medals stripped than the rest of the world combined). WADA, the World Anti-Doping Agency, was formed in 1999 by the IOC, and is the world's leading organization in the fight against doping in sports. Their actions in the past two decades have led to large improvements in testing methods and regulations, and they have helped to identify many cheats throughout this time. In spite of this, it was not until Russian whistleblowers came forward in the early 2010s that the largest doping scandal in the world came to light.

Starting in 2010, a small number of athletes and testing officials reported that RUSADA (the Russian Anti-Doping Agency) was deliberately working against WADA to help athletes cheat and conceal this from testing authorities. The allegations implicated many renowned athletes and high-ranking testing officials, and even indicated that President Vladimir Putin was aware of these activities. In the wake of these revelations and WADA's investigations, 145 Russian athletes have been added to the "most suspicious" list, and have been banned from taking part in any major athletics tournaments. Since 2010, Russian athletes have been stripped of more medals than any other country, 29 medals were stripped from Russian competitors relating to the 2008 and 2012 games alone. In December 2019, WADA announced that RUSADA were still non-compliant with international procedures and regulations, and Russia would be banned from all major sporting events for a period of four years. WADA did, however, allow Russian athletes to participate in the Tokyo Games provided they had been individually cleared by WADA and represented the Russian Olympic Committee, and not Russia.