BPC-157. TB-500. MOTs-C. If those sound like droids from a Star Wars spinoff, congratulations on your healthy relationship with the internet. For everyone else: peptides are the injectable wellness trend that jumped from bodybuilding forums to med spas to your feed, promoted for healing, muscle, fat loss, and living forever. But what does the science say, and what are peptides, actually?

Some of them became legitimate blockbuster drugs: insulin is a peptide, and so are the GLP-1s. But the ones flooding your feed never went through human trials. They went from lab animal studies straight to "research chemical" websites, and from there to longevity clinics charging four figures for injections of compounds nobody has proven do anything in people.

This week, Zoë traces how we got from insulin to Instagram: the bodybuilding underground, the anti-aging clinics, and the influencer economy that turned unproven injectables into a billion-dollar category. Kylee breaks down what the research actually shows for the big-name peptides, why "thousands of patients swear by it" is not evidence, and what she tells athletes who ask whether BPC-157 will fix their tendons faster. Plus: what to know about anything sold in a vial labeled "for research purposes only."

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