Users claim synthetic proteins aid weight loss, anti-ageing and muscle repair, but concerns abound over regulation
Once a niche interest among powerlifters and bodybuilders, the injectable substances have flooded the online wellness sphere. Social media is awash with people raving about their effect on everything from weight loss to concentration. Athletes and wellness influencers hail peptides as a way to speed muscle recovery and slow ageing. Demand is surging and authorities are “starting to take notice”.
Short chains of amino acids (small proteins) produced by our bodies to help regulate hormones, reduce inflammation and repair tissue. Synthetic versions are manufactured to mimic, or even enhance, those naturally occurring proteins.
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Peptides are the P in GLP-1s (the class of weight-loss drugs that includes Ozempic and Wegovy). Plenty of long-established drugs, such as insulin, are peptide-based – but “grey-market injectable peptides” are “unregulated, experimental compounds”, said The Guardian. Some are “bootleg versions of approved drugs”, sold for “a fraction of their market price” online.
In the US, the Food and Drug Administration (FDA) bars pharmacies from compounding peptides, but they can be bought from manufacturers in China, which export them under the label “for research purposes only”, or “not for human consumption” – a legal loophole. In practice, they are “packaged, dosed and marketed in ways that clearly anticipate human use”, said three public health experts from Australia on The Conversation. This creates “a parallel market”, outside clinical oversight and regulation.
According to US customs data, imports of hormone and peptide compounds from China reached $328 million in the first three quarters of 2025, up from $164 million in the same period the previous year, said The New York Times.
Many peptides and cosmetic injectables are sold with claims that they can accelerate skin repair, improve wrinkles and even reverse aspects of ageing. But high-quality human evidence is limited. Most claims are based on “a handful of laboratory studies”, usually on animals, said the public health experts on The Conversation.
Using peptides is “unfounded and reckless”, Eric Topol, director of the Scripps Research Translational Institute, told The New York Times. Last year, two women were hospitalised after injecting unknown peptides at a Las Vegas anti-ageing festival.
They lack “reliable safety data and quality control”, said The Guardian. According to Taylor, users are “converting themselves into the guinea pigs or the lab rats”.
Precise numbers are impossible to discern, but wellness influencers, bio-hackers and Silicon Valley tech bros are among those publicly endorsing the practice.
Unregulated peptides have “flooded some corners of the tech scene” in the US, said The New York Times. They’re showing up in “hacker houses, start-up offices and even ‘peptide raves’”. Tech podcaster and self-proclaimed “gym bro” Jayden Clark posted on X that “the elites all have a Chinese peptide dealer”. The term “Chinese peptides” has become a meme.
US podcaster Joe Rogan claims peptides BPC-157 and TB-500, a combination known as the “Wolverine stack” after the Marvel superhero, help with injury recovery. Robert F. Kennedy Jr, the US health secretary, says he is “a big fan of peptides”. In 2024, RFK Jr said on X that he would end the FDA’s “aggressive suppression” of peptides.