Peptides are short chains of amino acids—typically between 2 and 50—that serve as the building blocks of proteins. Linked together by peptide bonds, they are naturally produced by the body and play many important roles, such as acting as hormones, enzymes, or signaling molecules. When these chains become longer and more complex (usually over 50 amino acids), they form proteins. Peptides are involved in several key functions in the body, including blood pressure regulation and fluid balance. A well-known example is insulin, a 51-amino-acid peptide hormone that helps regulate blood sugar levels. Since the early 20th century, researchers have been developing synthetic peptides to support medical treatments—insulin, in fact, was the first lab-made peptide used to treat type 1 diabetes in 1923. Today, peptides continue to be studied for their potential in supporting wound healing, collagen production, weight-loss and muscle development.