Actor Eddie Redmayne called out the “vitriol” hurled at Harry Potter author J.K. Rowling after she broke with her industry peers on transgenderism and said the concept of sex must be based in science. Redmayne called the backlash against Rowling “absolutely disgusting.”

Redmayne defended Rowling after the author was attacked in recent months in the wake of her comments regarding transgender people, as well as suggesting that only women can menstruate. In a recent interview with Daily Mail, the actor said that while he strongly disagrees with Rowling, he nonetheless believes that the way the author has been treated is “absolutely disgusting,” and he has been prompted him to write her a private note.

Redmayne added that insults toward transgender people are “equally digesting.”

Rowling has been attacked by leftists and her fans for publicly defending the concept of biological sex — a scientific truth largely rejected by the left — telling her 14.5 million Twitter followers that it “isn’t hate to speak the truth.”

“If sex isn’t real, there’s no same-sex attraction,” she wrote. “If sex isn’t real, the lived reality of women globally is erased. I know and love trans people, but erasing the concept of sex removes the ability of many to meaningfully discuss their lives. It isn’t hate to speak the truth.”

The bestselling author also stirred controversy after she suggested that only women can menstruate.

“‘People who menstruate.’ I’m sure there used to be a word for those people. Someone help me out. Wumben? Wimpund? Woomud?” wrote Rowling in June, reacting to an article, entitled, “Opinion: Creating a more equal post-COVID-19 world for people who menstruate.”

The most recent attacks hurled at Rowling have been in response to her latest novel, Troubled Blood, which is reportedly about “a murderous cis man who dresses as a woman to kill his victims.”

While under attack, Twitter allowed the hashtag #RIPJKRowling to trend on the platform, despite the fact that she is not dead.

Redmayne did not initially defend Rowling after she had fallen under intense security. The actor initially mansplained what it means to be a woman to Rowling.

You can follow Alana Mastrangelo on Twitter at @ARmastrangelo, on Parler at @alana, and on Instagram.