Peptides Are All the Rage, Promising Miracle Cures and Makeovers Delivered by Injection. How Did We Get Here?

Peptides seem like they’re everywhere: on social media, on medical spa menus and beyond. Name your problem, and you can probably find a peptide—with a cryptic moniker like BPC-157 or GHK-Cu—that promises to help. A few years ago, these drugs belonged to the world of bodybuilder message boards and the dark web.

Today, they’re sold via polished websites with a medical gloss, with each peptide promising to deliver a remarkable benefit, such as weight loss, younger-looking skin or muscle repair. In Silicon Valley, devotees have gathered at peptide parties to drink, dance and inject themselves with these chemicals—all in pursuit of sharper minds and more sculpted bodies. But within the last few years, peptides have become a much broader phenomenon, not just taken for self-optimization but for treating chronic pain and various other conditions.

Simply put, peptides are short chains of amino acids—the building blocks of proteins—that carry specific instructions to specific cells. By linking up various amino acids in sequence, the body produces peptides that carry out a wide range of functions, including immune support, tissue repair and appetite control. Scientists, in turn, have developed synthetic copies or modified cousins of these peptides to use as medications.

By contrast, many peptides available for purchase online are experimental chemicals: They are not approved by the Food and Drug Administration and are openly sold with disclaimers, such as “for research use only.” As yet, these peptides are “completely untested and unregulated,” says Deborah Doroshow, an oncologist and historian at Mount Sinai in New York. There’s little to no research proving these molecules are safe or effective and no assurance from the FDA about their identity, purity or strength. Despite the uncertainty around them, peptides have garnered a cult following.

According to a recent survey of over 500 physicians, nearly half said a patient had disclosed using an experimental peptide in the past year. This boom is even more visible online: As of May, peptide-related hashtags had generated more than 130,000 Instagram posts and 230 million TikTok views. Teenagers and retirees alike broadcast before-and-after pictures and trade their “stacks,” or custom combinations of peptides, like recipes.

Experts say the peptide boom offers a window into a larger transformation in American health care: a shift from a market driven by diagnoses to one driven by demand, in which medicine is increasingly viewed as a consumer good—an Amazon-like product delivered to your doorstep. Peptides have long been essential medications. The first one was insulin: In the 1920s, scientists isolated the peptide from animal pancreases and began using it to treat Type 1 diabetes.