peptide

noun

1. Any 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.”

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

   “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.”

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

   “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.”