Jose Luis Castillo was fined US$250,000 and his Nevada boxing license was suspended for the rest of the year for failing to make weight for a June 3 title fight against Diego Corrales.
The Nevada Athletic Commission also banned him from fighting below 140 pounds (63.5 kg) in the state.
The commissioners, at a hearing on Thursday at the Reno-Tahoe International Airport, were angered by Castillo's testimony that an unidentified member of his camp offered to draw his blood to help him shed weight.
"That was an outrageous suggestion and to his credit, he said no," commission member Tony Alamo said.
"If you truly care about a person, you don't offer to drain their blood so they can lose weight to fight," he added.
Castillo weighed in June 2 at 139.5 pounds (63.3 kg) -- 4.5 pounds above the 135-pound limit for a lightweight title match. Losing 900g would have salvaged the fight as a non-title bout.
While imposing the maximum fine, the commissioners decided not to revoke Castillo's license, which would have made him unable to reapply for 12 months.
The fine was the largest given to a boxer in Nevada who did not receive a purse. Neither fighter was paid after the bout was canceled at the Thomas & Mack Center in Las Vegas.
Axel Murillo, a Las Vegas-based weight-loss expert, testified about a failed attempt to help Castillo shed weight by putting him in an impromptu sauna created by burning alcohol in his bathroom. Murillo said Castillo was too dehydrated for the attempt to work.
Corrales promoter Gary Shaw called the commission sanctions too lenient, and said he was angered that Corrales wasn't invited to testify.
Corrales is suing Castillo and his promoter, Top Rank Inc, over the canceled bout.
A lawsuit that was filed on June 12 in New York state court in Manhattan seeks payment of a US$1.2 million purse, plus US$750,000 for Shaw Productions LLC and US$10 million in punitive damages.