NEW YORK• Dr Jen Gunter, an obstetrician and gynaecologist in the San Francisco Bay Area, did not mean to pick on Goop, actress Gwyneth Paltrow's lifestyle and wellness e-commerce company.
In fact, she is a fan of Paltrow's acting.
"Shakespeare In Love is one of my favourite movies," Dr Gunter said of the 1998 film. "She was so wonderful in that movie."
But she does not think much of the stories posted by Goop on health and sex.
One that sent the doctor to her blog earlier this year was the suggestion in a Goop story that women insert jade eggs into their vaginas to improve their sex lives.
"I read the post on Goop and all I can tell you is it is the biggest load of garbage I have read on your site since vaginal steaming," Dr Gunter, 51, wrote on her personal blog, which carries the tagline "Wielding the Lasso of Truth".
Another Goop story that said bra-wearing may increase the chance of breast cancer also irked her. "It's breast size that increases the risk of breast cancer," she wrote in retort.
What about another practice recommended by a doctor interviewed on Goop: cleansing the body with goat's milk as a hedge against parasites?
"I'd just write it off as crazy except some people are going to follow this advice and waste a lot of money," Dr Gunter wrote, adding a certain modifier before "crazy".
Goop, which held the In Goop Health conference last month in Culver City, California, for acolytes who paid US$500 (S$680) to US$1,500 a ticket, had 1.8 million American visitors to its website last month, a 62 per cent increase from the previous June, according to comScore, an analytics company.
Comparatively, Dr Gunter's blog is small potatoes.
It is hard to navigate and antiquated in design, and failing to meet comScore's threshold of about 50,000 unique visitors a month, its Web traffic is too meagre to be measured.
However, after posting a few viral essays in recent years, Dr Gunter has emerged as the most ardent critic of Paltrow's website, routinely responding with snark and medical data to its pronouncements on diet and female genital health.
It may have been the lectins - which are plant proteins that have been targeted on Goop by one of its contributors, Dr Steven Gundry - that finally got to Paltrow and the Goop team.
After Dr Gunter posted a sweeping rebuke of several of the alternative health trends promoted by Goop, including a diet low on lectins, Goop posted a retort, which Paltrow tweeted to her nearly three million followers, along with a line that alluded to a Michelle Obama speech: "When they go low, we go high".
The post was intended to take a stand for open discussion about alternative approaches to health and wellness, said Ms Elise Loehnen, head of content for Goop.
The doctors interviewed by Goop are "highly vetted" and offer advice based on "evidence from their own practices", Ms Loehnen said, adding that Goop's wellness stories include a standard disclaimer.
Titled Uncensored: A Word From Our Doctors, Goop's "we go high" post seemed to single out Dr Gunter (without naming her but referring to her "wielding the lasso of truth" line) as looking to "critique Goop to leverage that interest and bring attention" to herself.
In a section attributed to "Team Goop", it went on to note Dr Gunter's "strangely confident assertion that putting a crystal in your vagina for pelvic-floor-strengthening exercises would put you in danger of getting toxic shock syndrome".
The rest of the post was written by two of Goop's featured doctors, including one who cited Dr Gunter by name and castigated her for using swear words.
"Now, it's fine to get into a reasonable discussion about the pros and cons of lectins without throwing F-bombs," Dr Gundry wrote. "Dr Oz and I just had a friendly discussion on this topic - you might learn something if you tune in."
The flame war continued with another post from Dr Gunter titled Goop's Misogynistic, Mansplaining Hit Job.
"I am not strangely confident about vaginal health; I am appropriately confident because I am the expert," she wrote.
She then cited her credentials, which include a medical degree from the University of Manitoba, a residency at the University of Western Ontario and a fellowship in infectious disease at the University of Kansas Medical Center.
The post has generated 157,000 page views, she said. Other medical professionals have written in support of her.
Dr Gunter, who works as a gynaecologist and obstetrician for Kaiser Permanente in San Francisco, began to blog in 2010, around the time she published a book, The Preemie Primer. She has long written about "snake oil", she said, focusing on trends and products marketed to women to better their sex lives or vaginal health.
"Every single day, I am talking to women about how you shouldn't use this product and why you shouldn't use that product," she said.
She said she does not check the Goop website every day. She usually ends up there after she has grown frustrated with political tweets. "I try to shift my indignation to something I can do something about," she said.