Zabel's admission comes a few days after he was named in a French government report that identified cyclists who had tested positive for EPO during the 1998 Tour de France. He also admitted to blood doping and using cortisone.
"EPO, cortisone and then even blood doping. It's really a lot," said Zabel, a six-time winner of the Tour de France's green jersey competition for best sprinter.
The 43-year-old, who retired in 2008, had previously admitted in 2007 to having taken EPO in 1996, although he said he had stopped using it after one week.
However, now he has finally come fully clean, he explained how he graduated from EPO to blood doping as detection methods improved.
"In 2003, I had a transfusion of my own blood," he added before explaining why he had previously lied about his doping past.
"First and foremost I wanted to preserve my life, the dream life of a professional cyclist.
"I loved it so much, the discipline, the travel. Basically, my selfishness was the strongest [thing]."
The inquiry by the French government commission into the effectiveness of the fight against doping decided to publish on Wednesday the results of samples from the 1998 and 1999 Tours that were retroactively tested for EPO in 2004.
In 1998 there wasn't an effective test for EPO so the drug went undetected.
Zabel, fellow sprinter Mario Cipollini as well as known dopers and former Tour winners Marco Pantini and Jan Ullrich were amongst the cyclists revealed to have used EPO in 1998.
Disgraced former seven-time Tour winner Lance Armstrong's samples from the 1999 Tour, the first one he won before later being stripped of all his titles, also tested positive for EPO.
Zabel actually tested positive for a banned anabolic steroid in 1994, right at the start of his career, but got away with a fine of 3,000 Swiss francs and no suspension.
In 2007 in the wake of admissions from former teammates and team officials from his former squad Telekom that doping was systematic in the German outfit, Zabel had said he tried EPO for just one week in the lead up to the 1996 Tour before stopping due to side effects.
However, his new admission shows that he in fact continued using doping products throughout the majority of his career, and principally the most successful period when he won six successive green jerseys from 1996 to 2001.