When Jennifer Gunter, MD, learned that Marie Claire magazine published an article suggesting that the recent solar eclipse affected menstrual cycles, she turned to social media to dismantle that assertion.

“If the new moon were associated with menstruation, then all women all over the world would be menstruating at the same time,” Dr. Gunter wrote in an Aug. 21, 2017 entry on her personal blog, which includes the slogan “Wielding the Lasso of Truth.” “Have none of these people ever considered that? Maybe that happens in the “Mists of Avalon,” but it doesn’t happen on Earth.”

Then there were the health claims published on goop , a lifestyle website started by actress Gwyneth Paltrow, alleging that women can improve their sex lives by inserting jade eggs into their vaginas, that wearing bras is linked to breast cancer, and that tampons contain toxins. “It is possible that, if goop got their tampon information from a gynecologist, they would know that 40 years of exclusive tampon use would expose a woman to a maximum of 1 mg of glyphosate over her lifetime,” Dr. Gunter wrote in a blog entry on July 14, 2017. “According to European standards a 50-kg woman can safely eat 25 mg of glyphosate a day. A lifetime of heavy tampon use doesn’t approach the amount of glyphosate allowed for one day of oral intake. Pointing this out with snark is only mocking the person at goop who couldn’t be bothered to look it up.”

Disputing such claims “keeps me pretty busy,” said Dr. Gunter, who’s become a hero to many in the ob.gyn. community, with more than 55,000 followers on Twitter and about 5,000 subscribers to her blog, which she launched in 2010.

“When I go to medical conferences, I get lots of physicians high-fiving me and thanking me, and that’s really nice,” she said. “They’re just like me. They’ve sat with patients and tried to explain how bioidentical hormones aren’t ground up yams and why salivary hormone testing is not recommended. They tell me that they’ve taken my blog posts and turned them into handouts. That’s the kind of thing that keeps me going: knowing that I’ve written something that’s going to help somebody else.”

Dr. Gunter, who practices gynecology in San Francisco, said that she established a social media presence because she’s compelled to wage war against medical misinformation, especially content marketed to women. “I can’t stand seeing websites that tell people they can lose weight doing this new fad or by taking certain supplements,” the Winnipeg, Canada, native said. “That’s the same snake oil that used to go town to town in the 1800s. It’s not any different; it’s just on a larger scale. Misinformation makes me sad. If people are making informed choices that’s one thing, but if they are hooked in by fancy websites with attractive celebrities and doctors branding supplements with their names, that bothers me. The Internet is only as good as the information you put into it. When you search for something, it’s really a shame that an accurate website isn’t coming up first, but it’s all driven by page clicks. What’s surprised me the most has been that people were ready for a voice like mine to stand up. I think the same feelings I’ve had have been brewing for a lot of people.”

Dr. Gunter devotes about 45 minutes every weekday to social media. Inspiration for her blog posts and her tweets on @DrJenGunter come from a variety of sources, often from followers who send her links to articles about wild medical claims. “I might post on my lunch hour but never during the work day,” she said. “A lot of people like to unwind at the end of the day by watching TV. I’m divorced and my kids are with their dad half the time so on the evenings when I’m by myself, if I’ve read something interesting, I’ll tweet about it.”

She shared the following tips for ob.gyns. looking to establish a presence on social media: