Peptides are short chains of amino acids — the same building blocks that make up proteins. The difference between a peptide and a protein is simply length: peptides contain 2–50 amino acids; proteins contain 50+. This smaller size gives peptides unique properties: they're absorbed more easily, can cross biological barriers more readily, and are highly specific in their receptor targeting.
The human body naturally produces hundreds of peptides with critical functions: hormones (insulin, glucagon), neurotransmitters (endorphins), immune modulators, and growth factors are all peptides or peptide-derived. Therapeutic peptide therapy leverages this biology — introducing specific peptides to direct desired physiological responses.
Over 7,000 naturally occurring peptides have been identified in the human body. Therapeutic peptide research has yielded 60+ FDA-approved drugs, with 150+ more in clinical trials — one of pharma's fastest growing categories.
The key advantage of peptides over traditional drugs is specificity: a peptide like CJC-1295 signals the pituitary to release growth hormone through a highly targeted mechanism, versus a drug that might broadly affect multiple systems. This specificity translates to cleaner side effect profiles and more predictable outcomes.