“I was blown away with how well it worked,” Gronkowski said at a news conference.

Gronkowski, who retired in March, said CBD — or cannabidiol, a nonintoxicating chemical in cannabis — was the only thing that took away the pain caused by more than a decade of punishing hits on the football field.

CBD, a cannabis substance that is quickly emerging from the fringes of alternative medical treatment, took a big step toward mainstream acceptance Tuesday as retired Patriots star Rob Gronkowski announced that he is the new face of a company touting the drug for myriad ills.

The announcement by the three-time Super Bowl champion instantly raised the profile of a substance that is exploding in popularity, even as questions swirl about its legality and medical effectiveness. Though Gronkowski is the latest in a long line of celebrities to promote CBD, his endorsement could signal a key moment in the drug’s evolving acceptance among sports leagues and consumers.

“It really is a step toward greater knowledge about the benefits of the substance and it really is important in the NFL, perhaps as much as anywhere in society,” said Steve Fox, strategic adviser for the Cannabis Trade Federation, a national industry group. “It makes a difference when athletes get involved, given the fact that they generally care about what they put in their bodies.”


Gronkowski, who has begun exploring various business ventures in his post-football life, said he first tried CBD a few months ago on the recommendation of his father, who used the product daily for his back pain.

Christopher Gasper: Gronk has a point: Athletes should be allowed to use CBD

“I am pain-free, and that is a big deal,” the 30-year-old former tight end said as he promoted his partnership with Abacus Health Products, the makers of the CBDMEDIC line of topical creams, lotions, and ointments.


Cannabis of any kind, including CBD, is banned in the NFL, as well as other professional sports leagues, although some forms have been legalized federally. The CBDMEDIC products are made with hemp, a type of cannabis plant that is similar to marijuana but has very little THC, the compound that can make a person high. Hemp is legal under federal law; marijuana is not.

Hype over CBD has spread internationally with wild claims that the drug can cure all types of maladies from cancer to Alzheimer’s, despite a lack of scientific evidence. Federal officials have slapped dozens of companies for marketing CBD with unsubstantiated claims out of concern that patients will forgo medical care because they believe CBD is treating their condition.

The US Food and Drug Administration is developing CBD regulations and has said companies cannot sell food products with CBD, or market the products as having any medical benefits. Massachusetts officials have backed up that ban.

Curaleaf, a Wakefield company and one of the country’s largest cannabis businesses, was the latest to be admonished by the FDA for selling CBD products with unfounded medical claims. Curaleaf removed the problematic wording.

Topical products like CBDMEDIC are generally allowed by the FDA, although the company’s website — which claims its products treat arthritis and muscle and joint pain — could draw scrutiny similar to what Curaleaf faced.

While more research is needed, doctors say so far there is no evidence that CBD products are effective at treating people’s pain.


CBD skin ointments and lotions, like those Gronkowski is promoting, have not been proven to relieve pain and cannabis’s active chemicals don’t generally absorb through the skin, said Dr. Jordan Tishler, of InhaleMD, a Massachusetts cannabis-focused medical practice.

“To boil it down, no, topical CBD doesn’t work,” Tishler said, adding that people’s claims of miraculous results could be linked to the powerful placebo effect.

But Gronkowski said Tuesday that the products were “life-changing” for him. When he decided to leave football, he said, he was struggling. He wished he could have used CBD to relieve the pain while he played.

“I needed to recover,” Gronkowski said, his voice cracking. “I was not in a good place. Football was bringing me down, and I didn’t like it.”

“During that time, I had countless injuries and nine surgeries, which took an absolute beating on my body and my soul,” he continued. “I was hurt both mentally and physically, day in and day out. I decided to walk away from the game for one main reason: I had to recover.”

In Gronkowski’s nine years with the Patriots, he suffered myriad injuries, including a broken forearm in 2012, which took four surgeries to heal. He tore a knee ligament in 2013, and in the Super Bowl last February, a blow to his leg left him with major swelling.

He implored sports leagues to change their cannabis policies to allow athletes to use CBD while recovering from injuries. The NFL punishes players who test positive for marijuana with fines, game suspensions, and bans.


“I’m here today to appeal to the sports-governing bodies of the world to update their position on CBD whether that’s the NBA, MLB, or NFL,” he said. “It’s just time.”

In May, the NFL announced the creation of a committee to research “pain management and alternative therapies,” which could include the use of marijuana among athletes. Dr. Allen Sills, the NFL’s chief medical officer, also said marijuana and CBD would be considered as alternative treatments.

For NFL players, pain is a constant reality and often their only option to treat it are opioids, which team doctors freely prescribe, said Eugene Monroe, a former Baltimore Ravens offensive lineman turned cannabis advocate. Monroe finds marijuana more effective than CBD for relieving his stiff ankles, knees, and back.

Other former NFL players Ricky Williams, Joe Montana, and Jim McMahon have all become outspoken advocates for cannabis, too.

Many players secretly use CBD now, he said, because they think the league doesn’t test for it, but they should have access to marijuana, as well.

“The NFL should not be punishing adults for consuming something that’s safer than what the team doctors are prescribing,” Monroe said.

Cannabis could become a central issue when players negotiate their next contract with the league, as most teams are based in states with legal medical or recreational marijuana. Monroe worked with the group Doctors for Cannabis Regulation on a recent campaign to change the NFL’s cannabis policy that argued the NFL’s current rules hurt players and disproportionately penalize black athletes.


Harvard University is working with former NFL players — including ex-Detroit Lions Calvin Johnson and Robert Sims — to study cannabis’s potential in treating pain and chronic traumatic encephalopathy, or CTE, a brain disease caused by repeated head trauma that afflicts many football players.

Ben Volin of the Globe staff contributed to this story. Felicia Gans can be reached at felicia.gans@globe.com. Follow her on Twitter @FeliciaGans.