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.

Sydney Haddon seen showing her “stack” of peptides.…