Ultimate Fighting Championship [UFC] superstar Jon Jones has blamed a sexual-enhancement pill for a positive drugs test which has seen him banned for 12 months by the United States Anti-Doping Agency (USADA). The 29-year-old was withdrawn from UFC 200 in June after being provisionally suspended for testing positive for banned substances clomiphene and letrozole, and following an investigation, has been banned for 12 months.

Jones had protested his innocence and insisted he was "1000%"certain he had not taken performance-enhancing drugs in the lead-up to his UFC light heavyweight championship unification rematch with Daniel Cormier in Las Vegas. His attorney, Howard Jacobs, claimed Jones believed he had ingested sexual-enhancement pill Cialis – which cures erectile dysfunction – after obtaining it from teammate Eric Blasich and the checking with agent Malki Kawa.

The tablet eventually turned out not to be Cialis, but another form of Tadalafil which Blasich had purchased from AllAmericanPeptide.com, leading to the positive test. The three-man panel found that Jones' conduct was "reckless" having not properly confirmed what was contained within the substance or clarified the details of the pill with Kawa. However, having proved he did not take the pill to directly enhance his performance he has avoided an automatic two-year ban.

"On the evidence before the panel, [Jones] is not a drug cheat," the panel said. "He did not know that the tablet he took contained prohibited substances or that those substances had the capacity to enhance sporting performance. However, by his imprudent use of what he pungently referred to as a 'd*** pill,' he has not only lost a year of his career but an estimated $9m [£7.5m]."

USADA rigorously assessed the substance before discovering it contained the aforementioned banned substances – leading to the agency sanctioning Jones. The punishment is backdated to 6 July, the date Jones was withdrawn from his fight with Cormier, meaning he is free to return in eight months' time.

"Although I was hopeful for a better outcome in the USADA ruling today I am very respectful of the process in which they allowed me to defend myself," Jones, who could still face action from the Nevada State Athletic Commission, said in a statement to ESPN. "I have always maintained my innocence and I am very happy I have been cleared in any wrongdoing pursuant to the allegations made that I had intentionally taken a banned substance. I am pleased that in USADA's investigation they determined I was 'not a cheater of the sport.'

"Being cleared of these allegations was very important to me. I have worked hard in and outside of the octagon to regain my image and my fighting career and will take these next eight months to continue my training and personal growth both as a man and a athlete. Thank you to all of my fans, teammates, coaches, sponsors and to the UFC for their continued support."