Fitness expert Jillian Michaels warned Americans against a dangerous trend of buying unregulated, “gray-market” weight-loss peptides online and self-dosing.

Speaking on the “Fox News Rundown,” Michaels said foreign-sourced, unapproved chemical compounds pose severe health risks, including potential heart issues, vision loss and hormonal imbalances.

“These are very significant things that need to be further researched and discussed with your doctor before you decide, ‘Hey, this sounds like a miracle drug! And I’m buying it on the web, and I am dosing myself in the bathroom off of a Reddit forum,'” Michaels told Fox News’ Alex Hogan.

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She noted that although it’s “not difficult to get” peptide drugs online, consumers often don’t know the true source of the products they’re buying. Michaels warned Americans not to take these drugs “into their own hands,” but instead to use them under the supervision of a medical professional.

The federal government has cracked down on illegal sales and dangerous marketing tactics surrounding GLP-1 compounds. In March, the U.S. Food and Drug Administration (FDA) announced it had issued 30 warning letters to telehealth companies for making false or misleading claims about compounded GLP-1 products.

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“Compounded drugs can be important for overcoming shortages or meeting unique patient needs — but compounders should not try to compound drugs in a way that circumvents FDA’s approval process,” FDA Commissioner Marty Makary said in a statement.

In June, the U.S. Food and Drug Administration (FDA) issued a warning about unapproved GLP-1 drugs, noting that it had logged hundreds of adverse event reports potentially tied to the products. The agency warned that unapproved versions “do not undergo FDA’s review for safety, effectiveness and quality before they are marketed” and called out vendors falsely labeling chemicals as “for research purposes only.”

A stock image shows a woman holding a peptide injection pen at home. (martin-dm/iStock)

Michaels argued that the surge in illegal sales is largely driven by people trying to lose “vanity pounds” quickly after taking inspiration from extreme body transformations in pop culture.

“You’ve got women in particular, but men as well, in all the major cities that want to go from a size eight to a size two for their summer vacation, and they are getting these things on the gray market. And we’re starting to see the results of that in famous celebrities,” Michaels said, adding that many people are taking these drugs when they don’t need to.

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“Every week, there’s another famous celebrity whose face is being splashed through the headlines and on the front page of different publications… and they look gaunt, they look aged, they’re losing their hair. I mean, there are real serious ramifications for this,” she added.

While Michaels noted that FDA-approved GLP-1s can be appropriate under medical supervision for individuals with severe obesity or chronic health conditions, she warned that using them or unapproved peptides for minor weight loss carries risks that users overlook.

She pointed to potentially severe side effects, including vision loss and suicidal ideation.

If you or someone you know is having thoughts of suicide, please contact the National Suicide Prevention Lifeline at 1-800-273-TALK (8255).

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She added that when users stop taking unregulated weight-loss compounds, they often experience an aggressive rebound in hunger.

“You might think, ‘Oh, I’m doing this for my summer vacation.’ But then when you get off of them, all of a sudden you’re hungrier because you’ve impacted your body’s ability to make these hormones naturally,” she said.

“And you’ll get a cycle of yo-yo dieting that you no longer know how to stop because you messed up your own biochemistry. These things are not a joke, man. They are not something that you play around with for vanity purposes, for sure,” Michaels added.