USA Swimming's new policy requires trans women to have low testosterone levels for 3 years

• USA Swimming announced new hormone restrictions for trans women who wish to compete.
• The new policy states that trans women must have low levels of testosterone for three years.

USA Swimming, the national governing body for competitive swimming in the US, announced new hormone restrictions for trans women competing at the professional level on Tuesday.

Effective immediately, the new requirements state trans women must have a concentration of testosterone in their blood lower than 5 nanomoles per liter for at least 36 months. Trans women who want to compete must also provide evidence that going through puberty of the sex they were assigned at birth "does not give the athlete a competitive advantage over the athlete's cisgender female competitors."

The Athlete Inclusion, Competitive Equity and Eligibility Policy will require a panel of three independent experts to review the evidence provided by athletes who want to compete.

The guidelines have some of the longest required time frames on hormones for trans athletes, as the since-overturned International Olympic Committee regulations mandated 24 consecutive months of low testosterone levels. Less than a week prior to USA Swimming's new guidelines, the NCAA adopted new "case-by-case" guidelines concerning trans athletes that will consider "fairness, inclusion and safety for all who compete."

On January 13, Olympic Gold medalist swimmer Michael Phelps told CNN the NCAA and USA swimming needed to "level the playing field" in response to the success of trans University of Pennsylvania swimmer, Lia Thomas. Advocates say the regulations are a direct reaction to Thomas' record-breaking success.

"In what seems to be a last-minute policy change, USA Swimming and the NCAA are changing the rules in the middle of the season for athletes who have worked hard, followed the rules, and just want to swim," Joni Madison, Interim President of the Human Rights Campaign, said in a statement.

"There are still more questions than there are answers, but one thing is clear – transgender girls & women will be unfairly impacted by this new policy."

Similar regulations on hormones for athletes have been criticized for not having a basis in science and unfairly targeting trans women and intersex people, as testosterone levels alone have not been scientifically linked to heightened athletic performance.

"What we see is they base their information on myths, misconceptions, and stereotypes about the trans community," Chris Mosier, an advocate and the first out trans member of Team USA, previously told Insider. "They're largely comparing trans women to cisgender men."