From The Telegraph September 2016:

"David Millar, who was banned for doping in 2004, told Telegraph Sport on Monday that the drug was the most potent thing he took in his career, and that included the banned blood booster EPO and testosterone. Millar said it helped him to lose weight and still feel stronger than he did before.

His testimony is backed up anecdotally by other riders as well as by some randomised controlled trials [RCTs] with amateur athletes."