Former NFL lineman Jeremy Newberry says he often hobbled into the 49ers locker room using a walking boot and crutches, then lined up behind as many as two dozen teammates for treatment — in his case, a shot of the painkiller Toradol. Ten minutes later, he sprinted onto the field to play.

The toughness of pro football players is part of the league’s image, but a lawsuit filed Tuesday on behalf of more than 600 former players contends it was abetted by team physicians and trainers across the NFL who routinely dispensed powerful narcotics and other controlled substances on game days to mask the pain.

Although painkillers have been discussed around NFL locker rooms for decades, plaintiffs in this suit give details about which drugs they say teams persuaded them to use and how even severe injuries were covered up temporarily.

Painkillers Percodan, Percocet and Vicodin, anti-inflammatories such as Toradol, and sleep aids such as Ambien were “handed out like candy at Halloween,” according to lead attorney Steven Silverman. Sometimes, the lawsuit also charges, the drugs were given in combinations as “cocktails.”

“The stuff works,” Newberry, who played seven of his nine seasons in San Francisco before retiring in 2009, told The Associated Press in an interview. “It works like crazy. It really does.”

But only for so long.

Newberry, now 38 and one of the eight plaintiffs named in the lawsuit, says that because of the drugs he took while playing, he suffers from kidney failure, high blood pressure and violent headaches. Others — including three members of the NFL champion 1985 Chicago Bears: quarterback Jim McMahon, Hall of Fame defensive end Richard Dent and offensive lineman Keith Van Horne — reported a range of debilitating effects, from chronic muscle and bone ailments to permanent nerve and organ damage.

NFL Commissioner Roger Goodell, in Atlanta for the league’s spring meetings, said Tuesday that league attorneys had not yet studied the lawsuit.

Six of the named plaintiffs in the suit filed in federal court in San Francisco were also parties to the concussion-related class-action lawsuit less than a year ago. The NFL agreed to pay $765 million to settle that case — without acknowledging it concealed the risks of concussions from former players. A federal judge has yet to approve the settlement, expressing concern the amount is too small.

“The difference is that the concussion case claimed the NFL knew or should have known,” Silverman said. “We’re saying this was intentional.”