Olympic gold metal winning cyclist and former Lance Armstrong teammate Tyler Hamilton told 60 Minutes that he witnessed Armstrong taking EPO, a banned substance that boosts your red blood cell count thus enabling your body to more efficiently transfer oxygen to the muscles, as well as other illegal performance enhancing drugs. Synthetic EPO was the doping drug of choice for pro riders during the 1990s and early 2000s.
“(Armstrong) took what we all took … the majority of the peloton. … There was EPO … testosterone … a blood transfusion.”
("Peloton" is the French word for "the group" -- commonly used to designate both a large group of riders, or the general field of pro riders.)
If you read the article, note the number of reacts in which teammates and other riders don't commit to defending Armstrong. That speaks volumes about how toxic (figuratively) Armstrong is right now.
It's worth noting, however, that it was exactly a year ago, also during the Amgen Tour of California, when Floyd Landis unveiled latest accusations against Armstrong. Both Landis and Tyler Hamilton were banned from cycling for doping.