An Etsy page claiming that ground-up oak galls are good for vaginal health is just the latest piece of questionable medical advice to be found online.

First there was Goop, now there are galls.

Oak galls, to be precise. These little balls, 1 to 2 inches in diameter, are found in oak trees. They’re made up of bark and chemicals injected by the larva of certain types of gall wasps.

Now, they’ve found their way onto Etsy, the e-commerce site that specializes in handmade and vintage items, as a supposed homeopathic way to tighten a woman’s vagina.

It’s far from the first time that dubious medical advice has gone viral. And this purported remedy has health professionals shaking their heads.

Jen Gunter, OB-GYN and pain medicine physician, sounded the alarm over the oak gall advice on her personal blog in a post last month, “Don’t put ground up wasp nest in your vagina.”

Gunter notes that salicylate, the phenolic acid found in many types of tree bark, has been used to treat pain and fever for centuries. But putting astringents directly in one’s vagina, as the Etsy page recommends, is a definite no-go.

“This product follows the same dangerous pathway of other ‘traditional’ vaginal practices, meaning tightening and drying the vagina, which is both medically and sexually (for women, anyway) undesirable,” she wrote in her blog.

“Drying the vaginal mucosa increases the risk of abrasions during sex (not good) and destroys the protective mucous layer (not good). It could also wreak havoc with the good bacteria. In addition to causing pain during sex it can increase the risk of HIV transmission. This is a dangerous practice with real potential to harm. Here’s a pro-tip, if something burns when you apply it to the vagina it is generally bad for the vagina.”

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While the oak gall therapy came from an Etsy seller and not a celebrity, it’s part of a broader trend of questionable health advice that tends to spread online.

Often, this advice gets a wide audience because it came from a celebrity.

Case in point: Earlier this year, Gwyneth Paltrow touted the purported benefits of women putting jade eggs in their vagina.

This recommendation, published in Paltrow’s online health newsletter, Goop, attracted widespread condemnation from physicians.

A gynecologist interviewed by Healthline said that while Paltrow’s heart might be in the right place, she isn’t qualified to give such recommendations.

“Everyone in this world has their gift, and for Gwyneth Paltrow that gift is acting,” Dr. Christine Greves of Orlando Health’s Center for Obstetrics and Gynecology, told Healthline.

“[Paltrow] seems to have a good heart, and many people might see her health advice as well-intentioned and will want to follow it. But it’s incredibly important to ask, ‘Is this backed by a physician’s recommendations or not? Is it FDA approved?’ Ultimately, it’s best to talk to your physician before trying out a remedy you see online.”

In a March blog post, Gunter slammed the magazine Women’s Health for putting Paltrow on the cover and publishing some of her problematic health advice.

Gunter broke down some of her issues with Paltrow’s advice, writing, “Her advice on iodine could kill someone. Everyone is not suffering from chronic yeast infections that only some private doctor’s diet can cure. Using vaginal jade eggs could injure your pelvic floor. Bras will not give you breast cancer. If this is what Women’s Healthis okay calling wellness then they are either a simpering pandering pile of trash trying to cash in on the Paltrow crazy train, or they really believe there are toxins everywhere.”

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While it may be tempting to try out a new remedy you read about online, it’s always best to consult with your doctor beforehand.

It’s worth noting, Greves says, that doctors aren’t going to automatically reject a potential therapy just because it’s homeopathic in nature.

“It’s important for people to realize that when they’re talking to their physician, that physician isn’t necessarily going to pooh-pooh their ideas,” she told Healthline. “In fact, there are many homeopathic remedies that are advisable, depending of course on the patient’s condition.”

“All we can really do is advise our patients and try to educate them on the risks of potential treatments.”

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