Sitting in the passenger seat of a car, a high school teen clutches an insulin needle beneath her pursed lips. She overlays the social media video with a sexually charged caption: “when he says he wants to pin me so i lowkey grab the r3ta and he looks at me weird.”

No, this isn’t a new sexual fetish that today’s young people are into.

What the 17-year-old is referring to is retatrutide — a next-generation, triple-agonist weight-loss drug that the teen has managed to get her hands on for cheap as a quick fix to look more toned.

The peptide supposedly suppresses appetite, controls blood sugar, and increases energy. She’s been injecting 0.5mg every week for a month and has already lost 10 pounds. The high schooler also injects melanotan I, a tanning peptide that increases melanin production even with minimal sun exposure.

The teen sources her products through her boyfriend’s “connection” on Telegram, an encrypted messaging app.

“When I first started using them it felt a bit risky, but I made sure to collect as much information as possible,” she told The Post. “I’ve felt more confident on peptides for sure,” she added, noting that she has since gotten two of her friends to try them, who’ve also lost weight.

She’s not alone.

What started as a niche trend among bodybuilders and biohackers to lose fat and boost muscle growth is now making its way into high schools, as an alarming number of teens are experimenting with “sketchy” peptides to address body insecurities, favoring retatrutide, melanotan, and GHK-cu, a peptide known to boost collagen, something that seems counterintuitive for someone whose body is still naturally producing it.

A quick search of the hashtag #Peptide yields over 342,000 videos on TikTok, many of them showing users’ step-by-step tutorials, detailing everything from peptide “stacks” to dosing schedules and how to inject them at home. This content has become as ubiquitous as “What I eat in a day” videos.

Influenced by the broader “looksmaxxing” culture, where young people are encouraged to optimize their appearance, peptides are framed as shortcuts to rapid transformation. The result is an unusual number of tan, lean teenagers posing with syringes.

Access is easy. These products are often labeled “not for human consumption,” which allows them to remain on the market and in a legal and medical gray area with minimal oversight, allowing users to get their hands on them through social media, Amazon storefronts, messaging app “dealers,” or websites that sell them directly to consumers.

These “research use only” peptides are also typically less expensive, costing in the low to mid-hundreds, whereas if a doctor or compounding pharmacy prescribed them, they’d cost anywhere from low hundreds to thousands, depending on the peptide.

“Prices are very cheap, like $10 for 50 mg if you buy directly from China but the risk of scams is high,” cautioned a 22-year-old user who goes by the TikTok handle capitalchia. “With buying from US labs [has] less risk but [it] could be $100 for 10mg.”

“Spend five minutes online, and you can find a source, though you might get scammed,” the teen explained. 

But for users like Sydney Haddon, 18, the risk of this unregulated and expansive market is worth the seeming reward.

It didn’t take much convincing for Haddon to give retatrutide, which is hailed as a weight-loss champion with even early studies showing it’s significantly more effective than its predecessors, semaglutide or tirzepatide, a try.

No matter how much she dieted and exercised, the 18-year-old told The Post that she couldn’t shed stubborn weight from her face or stomach, making this particular peptide enticing. 

“I know many, many people my age and younger on peptides as well, more than I could count,” Haddon told The Post. “I feel pressured by this sudden trend of ‘looksmaxxing’ or just this overall trend of just fixing yourself.”

“It’s hard being a teenage girl and seeing these easy fixes to some of our biggest insecurities being promoted so heavily.” 

Haddon told The Post that the peptides that have helped her lose around 20 pounds in two months come from “numerous places, including US-marketed brands and from suppliers in China,” recommended to her by friends. 

“They all had their official labs and proof of real peptides,” said Haddon. “I’ve never felt unsafe taking it.”

Users like Haddon often use the drugs in combination with others, a process known as “stacking” to optimize their results. Teens mix concoctions akin to a high school chemistry lab, using powders, water, and precisely measured doses.

While many still live under their parents’ roofs, teens exercise discretion. Some invest in mini fridges hidden in their bedrooms, while others hide their peptides in a fake soda can in said fridge, since peptides need to be temperature-controlled to maintain potency.

This is alarming health practitioners like Dr. Samantha Nish, a licensed NYC clinical psychologist specializing in child and adolescent psychology. She often sees in her practice an “increasing pressure [for teens] to manage and improve their appearance, in part driven by social media environments that reinforce comparison and idealized standards.”

But that sense of control can also be part of the risk. In a culture where appearance is constantly evaluated and compared, the pressure to improve doesn’t necessarily stop once a goal is reached.

“There is often a sense that one is never ‘done,’ and that there is always another product, routine, or change that could bring them closer to an ideal,” Nish explained.

Among the teens he works with, psychotherapist John Puls said the pattern often follows a familiar progression.

“It usually starts with working out and trying to look better,” Puls told The Post. “Then it becomes obsessively tracking calories, weighing food, and eventually it can lead to injecting peptides.”

Over time, that focus can begin to interfere with daily life, according to Puls, who has treated teens who avoid social scenes involving food, skip family meals, or isolate themselves to maintain strict routines. Yet online, this type of behavior is praised as #leanislaw.

“It creates a cycle of obsession, anxiety and isolation,” he added — across both genders.

For boys in particular, the pressure often centers on achieving a hyper-lean, muscular physique, driven in part by looksmaxxing influencers like Clavicular, who has built a following of almost 600,000 Instagram followers by promoting extreme, often dangerous ways for men to improve their physical appearance.

“What’s different now is how early these concerns are emerging,” said Nish, noting that children as young as 9 or 10 are already engaging with appearance-focused trends online.

Many of the peptides circulating among teens are not only unregulated — they’re also being used in ways they were never intended.

Drugs like retatrutide are still in clinical trials and are being developed for patients with obesity or metabolic conditions under strict medical supervision.

“These are very potent drugs that are meant to be used under medical supervision, for specific indications,” said NYC-based longevity doctor, Dr. Amanda Kahn,

“These medications affect metabolism, appetite regulation, and hormone signaling,” Kahn said. “In a developing body, interfering with those systems can have long-term consequences we don’t fully understand.”

Tanning peptides add another layer of uncertainty.

Melanotan is marketed online as a way to achieve a darker complexion with minimal sun exposure. But experts say the science and the safety remain unclear.

“I’ve heard of racing heart, high blood pressure, flushing, headaches,” Kahn said, adding that she refuses to prescribe tanning peptides. “The risk-benefit ratio just isn’t there.”

More broadly, she said, many of these compounds are designed for use later in life and not during adolescence, when the body is still actively developing.

“These are being used as a kind of shortcut or workaround,” Kahn said. “But that doesn’t come without a cost.”