UFC heavyweight Josh Barnett is going after the company he alleges caused a positive drug test and upended his UFC career.

Barnett (35-8 MMA, 7-3 UFC) on Monday filed a lawsuit in Los Angeles Superior Court against supplement company Genkor on grounds of negligence, breach of implied and express warranty, and strict product liability.

Genkor, based in Los Angeles, makes the Tributestin supplement Barnett took that was found by the U.S. Anti-Doping Agency to contain the banned anabolic agent ostarine.

Barnett claims the supplement company “poisoned” him with ostarine and cost him fight purses, attorney fees from his case with UFC anti-doping partner USADA, reputational harm, and physical and emotional distress as the result of the contaminated supplement.

READ: Josh Barnett’s full lawsuit against Genkor

“He has lost, and continues to lose income,” states the suit. “He has also suffered and continues to suffer reputational harm and emotional distress.”

Barnett seeks unspecified general and compensatory damages, in addition to attorney and court fees, to be determined at a trial.

As previously reported, Barnett became the first UFC fighter to be exonerated under the USADA program when a third-party arbitrator found he didn’t knowingly take ostarine and was the victim of a contaminated supplement. As a result, the veteran heavyweight received only a verbal warning from the anti-doping agency.

In an interview with MMAjunkie, Barnett spoke at length about the struggle to clear his name. He said the anti-doping agency initially tried to work with him but reversed course after identifying the tainted supplement. Then, USADA reps tried to strong-arm him into accepting an 18-month suspension by factoring in a 2009 drug positive, later found to be inadmissible by the arbitrator.

“I’m not against the idea and the spirit of USADA, or what an independent drug testing program is for – not at all,” Barnett said. “I don’t have an issue with any of these things, and even though I took a supplement that was tainted, I’m OK with having to go through the process to test the supplements. I’m totally fine with that.

“The only thing I protest to is being hammered after the fact, after finding that I am innocent of any wrongdoing, and instead of moving on and considering the time spent researching and finding the data and appealing my case as enough – the extra efforts to come after me, that’s where I draw the line.”

In the suit, Barnett claims he started taking the Tributestin supplement in fall 2016 with the expectation that it contained tribulus terrestris, a legal herb purported to boost natural testosterone. On Dec. 9, 2016, he submitted a urine sample to USADA that came back positive for ostarine. As a result, he was taken out of the running for a fight in September 2017 that would have paid him $275,000.

Barnett’s attorney, Peter Fredman, told MMAjunkie that lost fight purse serves as a baseline for potential damages available to Barnett but will increase with damages for reputational and emotional harm.

Fredman noted Barnett’s case might be unique among fighters who’ve claimed to have ingested supplements, given the UFC heavyweight’s diligence in tracking his supplement use. He said the case could serve as a blueprint for other fighters, too.

“If they could identify a solvent supplement maker that sold them a tainted supplement, they would have good cases, too,” Fredman said. “The fact that you sell a tainted supplement is a pretty serious thing.”

Although Barnett was exonerated by USADA, he will need to re-enter the USADA testing pool for six months before he is cleared to compete. He most recently was seen in the octagon in September 2016, when he submitted ex-UFC champ Andrei Arlovski at UFC Fight Night 93.

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