Dipeptide
Carnosine
Oligopeptide
Oxytocin
Peptide
BPC-157
Polypeptide
GLP-1 Long
Protein
Albumin
Peptides are short chains of 2 to ~50 amino acids linked by peptide bonds. They share the same building blocks as proteins but operate differently due to their smaller size and targeted structure.
Many peptides function as hormones, neurotransmitters, or growth factors — carrying chemical signals between cells, organs, and tissues. GLP-1, GH, oxytocin, and insulin are all peptides.
Unlike small-molecule drugs, peptides have delicate three-dimensional structures. Temperature, light, agitation, and pH can all degrade them, which is why proper handling is critical.
Over 100 peptide-based drugs are FDA-approved (insulin, semaglutide, linaclotide, etc.). Hundreds more are in clinical trials. Synthetic research peptides mimic these same biological pathways.
Peptide vs. Protein vs. Small Molecule
| Property | Small Molecule | Peptide | Protein |
|---|---|---|---|
| Molecular Weight | <500 Da | 500–5,000 Da | >5,000 Da |
| Amino Acid Chain | None | 2–50 AA | >50 AA |
| Examples | Aspirin, caffeine | BPC-157, GLP-1, oxytocin | Albumin, GH (191 AA) |
| Oral Bioavailability | Often high | Generally low | Very low / none |
| Stability | High | Moderate (fragile) | Low (very fragile) |
| Route of Admin | Oral / topical | Injection / topical | Injection |
Bind to Receptor
A peptide travels to its target tissue and binds to a specific cell-surface receptor — like a key fitting a lock.
Trigger Signal
Receptor binding activates intracellular signaling (often via cAMP or kinases), sending instructions into the cell.
Biological Effect
The cell responds — producing hormones, repairing tissue, modulating immunity, or altering metabolism.
