Jessica Penne, who competed for the UFC strawweight title back in 2015, announced her retirement from active competition after being suspended by USADA for four years following a second failed drug test.

Penne, 36 years old, revealed the news in a social media post, citing many issues with the testing structure used by the UFC and USADA. She is a former Invicta FC champion and also competed in the first-ever women's bout in Bellator MMA.

"I am heartbroken and defeated," Penne wrote on Instagram. "I spent thousands of dollars I didn't have testing medications and supplements. At my age there is no way I can come back in four years. At this point I am lost and defeated."

Penne battled several injuries, which she claims forced her to take different medication in hopes of competing again at full strength. She also noted several "not pleasant" run-ins with a member of the USADA staff.

"I am innocent," Penne said. "I don't know where I go from here. At this point USADA has held me from making a career and income for the last three years and I am ashamed to say I am broke, defeated and heartbroken.

"I love this sport and gave my life to it."

USADA responded with a statement sent to MMA Fighting, saying "Given Jessica Penne's public statement, we can confirm her positive test for stanozolol. However, there are many factual inaccuracies and unfounded allegations in her statement, including that she has been forced out of UFC.

"In fact, she has exercised her right to contest her case before an independent arbitrator, per a request USADA received after she released her public statement. Under the UFC Anti-Doping Policy, all athletes have the right to present the facts and circumstances during a full evidentiary hearing. We look forward to the opportunity to present the facts and evidence through this process."