peptide

plural peptides

1. chemistryAny of a class of organic compounds consisting of various numbers of amino acids in which the amine of one is reacted with the carboxylic acid of the next to form an amide bond. Such molecules joined into polypeptides and proteins constitute crucial components of living organisms.

   When it’s digested, its long amino-acid chains are first broken down into smaller fragments, or peptides. It turns out that many hormones and drugs are also peptides, and a number of casein peptides do affect the body in hormone-like ways.

   2004, Harold McGee, chapter 1, in On Food and Cooking: The Science and Lore of the Kitchen, Scribner, →ISBN

2. chemistryThe peptide bond itself.
3. euphemisticusuallyPerformance-enhancing drugs that contain such molecules, especially particular ones (often synthetically produced) that are claimed by their sellers to bestow amazing health benefits.

   It truly doesn’t, funny how so many people in this sub keep buying certain peptides for the placebo.

   2025 March 19, Reddit, archived from the original on 19 Mar 2025

   3 more examples

   Please be patient with me, I get hundreds of emails a day in regards to anything fitness related including diet, recipes, eating schedules, work out routines, recommending what peptides to take for what and so on.

   2024 June 3, Reddit, archived from the original on 19 Mar 2025

   But when online influencers talk about peptide therapy, they are generally referring to a vast constellation of emerging or experimental products, often in skin care, fitness or biohacking. These can be swallowed, injected or rubbed on the skin. […] For example, the “Barbie” peptide is often promoted by influencers and online clinics as a healthier way to tan without the sun — even though the F.D.A. has warned of “serious safety risks,” and research suggests it’s linked to an increased chance of cancer.

   2025 November 18, David Dodge, “The Internet Loves Peptide Therapy. Is It Really a Miracle Cure?”, in The New York Times, →ISSN

   So, I was sort of like a well-known name in a really small, tight-knit community. And then I kind of took it a little bit more serious because people were asking me, like, "How do you do this?", "What was your experience like with this peptide?", whatever, and it started to get a lot of traction very early on.

   2026 March 29, Andrew Callaghan, “Clavicular Interview”, in Channel 5 with Andrew Callaghan, via YouTube, 3:59–4:19