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# Peptides

pep·tides - PEP-tydz

## Definition

Peptides are short chains of amino acids linked by peptide bonds - typically containing between 2 and 50 amino acids. They are essentially small proteins and serve as signaling molecules, hormones, neurotransmitters, and antimicrobial agents throughout the body. While proteins are larger and form complex three-dimensional structures for mechanical and enzymatic functions, peptides tend to act as [chemical messengers](/glossary/hormone) that trigger specific biological responses.

Your body produces thousands of different peptides with diverse functions. Insulin (51 [amino acids](/glossary/amino-acid)) and glucagon (29 amino acids) regulate blood sugar. Oxytocin (9 amino acids) promotes bonding and uterine contractions. Endorphins modulate pain perception. Antimicrobial peptides (defensins) provide innate immune defense. [Growth hormone](/glossary/growth-hormone)\-releasing peptides stimulate growth hormone secretion. [Collagen](/glossary/collagen) peptides - fragments of the collagen protein - are widely used in supplements for skin, joint, and bone health.

Peptide therapeutics represent one of the fastest-growing segments of the pharmaceutical industry. Over 80 peptide drugs have been approved globally, treating conditions from diabetes (GLP-1 agonists like semaglutide) to [osteoporosis](/glossary/osteoporosis) to cancer. Peptides are also increasingly popular in cosmetic dermatology, where topical peptides are used to stimulate collagen production and address signs of aging.

## Also Known As

Polypeptides Short-chain amino acids 

## Key Facts

-   • Peptides contain 2-50 amino acids, while proteins typically contain 50+ amino acids. 
-   • Over 7,000 naturally occurring peptides have been identified in the human body. 
-   • GLP-1 receptor agonists (semaglutide, liraglutide) are peptide drugs revolutionizing treatment of type 2 diabetes and obesity. 
-   • Collagen peptide supplements are among the most popular peptide-based consumer products for skin and joint health. 
-   • Antimicrobial peptides produced by the skin and immune system are a critical first-line defense against infection. 

## How It Relates To Your Health

Peptides are increasingly relevant in modern medicine. If you've been prescribed semaglutide (Ozempic, Wegovy) for diabetes or weight management, you're using a peptide drug that mimics GLP-1, a natural gut peptide that regulates insulin secretion and appetite. Other peptide therapies include teriparatide for [osteoporosis](/glossary/osteoporosis), octreotide for hormonal tumors, and desmopressin for diabetes insipidus.

In the wellness and cosmetic space, collagen peptides, BPC-157, and various growth [hormone](/glossary/hormone)\-releasing peptides have gained popularity, though evidence levels vary widely. Some peptides available through compounding pharmacies or online sources are not FDA-approved for their marketed uses, making it important to discuss any peptide supplementation with your healthcare provider.

## Related Terms

[Amino Acid](/glossary/amino-acid)[Collagen](/glossary/collagen)[Insulin](/glossary/insulin)[Hormone](/glossary/hormone)[Growth Hormone](/glossary/growth-hormone)[Enzyme](/glossary/enzyme)

## Sources

1.  [Peptides](https://www.ncbi.nlm.nih.gov/books/NBK557791/) - StatPearls / PubMed
2.  [Therapeutic Peptides](https://www.fda.gov/drugs/pharmaceutical-quality-resources/peptide-drug-products) - U.S. Food and Drug Administration
3.  [Peptide Hormones](https://my.clevelandclinic.org/health/articles/peptide-hormones) - Cleveland Clinic

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