Peptides are a class of research chemicals that can be used off-label to enhance performance and/or improve quality of life. Peptides occur naturally and can be classified into dozens if not hundreds of categories.
They can be found in all living organisms, including humans, plants, and even fungi. As you may or may not know, some Peptides have gone through human clinical trials, while others have only been tested on animals. A big percentage of what we know about Peptides and their actions is not based on actual science, but on the anecdotal reports of thousands of users. In other words, the science on Peptides and other Research Chemicals is not settled yet.