What are the main types of peptides?

Natural peptide hormones, approved peptide medicines, cosmetic peptides, supplement peptides such as collagen, and unapproved research peptides.

What are examples of peptide drugs?

Insulin, semaglutide, liraglutide, tirzepatide, teriparatide, leuprolide and octreotide.

Are all peptides injected?

No. Many drugs are injected because peptides are digested, but collagen is eaten, cosmetic peptides are applied to skin, and oral semaglutide is a tablet.

Types of Peptides: Hormones, Medicines, Supplements and Research Peptides

Types of peptides explained with a list: natural peptide hormones, approved peptide drugs, cosmetic and supplement peptides, and unapproved research peptides. Not medical advice.

Anonymous user report. Not medical advice. Peptides discussed are not FDA-approved for the uses described. Editorial process →

Short answer

Peptides are short chains of amino acids (see what are peptides). They can be grouped by length (dipeptides, oligopeptides, polypeptides) or, more usefully, by what they are used for and how well they are tested: natural hormones, approved medicines, cosmetic and supplement peptides, and unapproved research peptides. Peptide Confessions does not publish dosing, timing, injection or sourcing guidance.

A list of peptide types by use

Last reviewed October 15, 2026.

Type	Examples	Evidence and status
Natural peptide hormones	Insulin, GLP-1, oxytocin, vasopressin, ghrelin, leptin	Made by the body
Metabolic drugs	GLP-1 receptor agonists (semaglutide, liraglutide), tirzepatide, insulin analogues	Approved; large trials
Hormone and bone drugs	Teriparatide, leuprolide, octreotide, desmopressin	Approved
Antimicrobial peptides	Vancomycin, daptomycin, colistin; LL-37 (natural, research)	Antibiotics approved; LL-37 research only
Cosmetic peptides	Copper peptides, palmitoyl pentapeptide-4, acetyl hexapeptide-8	Small studies; sold as cosmetics
Food and supplement peptides	Collagen peptides, whey and other protein fragments	Modest evidence
Growth hormone secretagogues	Sermorelin, CJC-1295, ipamorelin, tesamorelin	Tesamorelin approved for one use; others research or compounded
"Healing" research peptides	BPC-157, TB-500	Animal data; unapproved; banned in sport
Nootropic and longevity peptides	Semax, Selank, epitalon, MOTS-c	Mostly small or animal studies; unapproved in US and Canada

Why the type matters

The same word covers products with very different evidence and oversight. An approved peptide drug has a label, known side effects and manufacturing standards. A research peptide sold online has none of these, and testing has found wrong contents and contamination. Before trusting a claim, check which group a peptide belongs to. See are peptides safe? and peptide injections.

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Community Q&A

What are the main types of peptides?: Natural peptide hormones, approved peptide medicines, cosmetic peptides, supplement peptides such as collagen, and unapproved research peptides.
What are examples of peptide drugs?: Insulin, semaglutide, liraglutide, tirzepatide, teriparatide, leuprolide and octreotide.
Are all peptides injected?: No. Many drugs are injected because peptides are digested, but collagen is eaten, cosmetic peptides are applied to skin, and oral semaglutide is a tablet.
Does this page give dosing advice?: Peptide Confessions does not publish dosing, timing, injection or sourcing guidance.

Anonymous first-hand reports plus sourced context — educational only, not medical advice. Editorial policy & corrections.