JournalEducationPeptide Categories Explained: From Growth Hormone to Nootropics
Education

Peptide Categories Explained: From Growth Hormone to Nootropics

The world of research peptides spans numerous categories, each targeting different biological systems. This guide breaks down the major peptide families and their research applications.

Dr. James Chen

Senior Research Scientist

8 March 2026
11 min read

Overview of Peptide Categories

Research peptides can be broadly categorised based on their primary mechanisms of action and research applications. Understanding these categories helps researchers select appropriate compounds for their specific areas of study.

Growth Hormone Secretagogues

Growth hormone secretagogues (GHS) are peptides that stimulate the release of growth hormone from the pituitary gland. They work through two main mechanisms:

GHRH Analogues: These peptides mimic Growth Hormone Releasing Hormone. CJC 1295 (with and without DAC) is the most widely studied example. It stimulates GH release through the GHRH receptor pathway.

Ghrelin Mimetics: These peptides activate the ghrelin receptor (GHS R1a). Examples include Ipamorelin, GHRP 2, GHRP 6, and Hexarelin. They stimulate GH release through a pathway complementary to GHRH.

Combination Approach: Research often combines a GHRH analogue with a ghrelin mimetic (such as CJC 1295 plus Ipamorelin) for synergistic GH release.

Healing and Repair Peptides

This category includes peptides studied for their tissue repair and regenerative properties:

BPC 157: Derived from gastric juice, studied for gastrointestinal protection and multi tissue repair.

TB 500 / Thymosin Beta 4: Regulates actin polymerisation and promotes cell migration for wound healing.

Pentadecarginine: A newer compound studied for wound healing applications.

GLP 1 and Metabolic Peptides

The fastest growing category in peptide research:

Semaglutide: Long acting GLP 1 receptor agonist

Tirzepatide: Dual GIP/GLP 1 receptor agonist

Retatrutide: Triple GIP/GLP 1/Glucagon receptor agonist

AOD 9604: Growth hormone fragment studied for metabolic effects

Nootropic and Neuroprotective Peptides

Peptides studied for cognitive and neurological effects:

Selank: Synthetic analogue of tuftsin, studied for anxiolytic and nootropic properties

Semax: Synthetic ACTH analogue, studied for neuroprotective and cognitive effects

DSIP: Delta Sleep Inducing Peptide, studied for sleep regulation

Dihexa: Studied for cognitive enhancement through HGF/MET pathway

Anti Aging and Longevity Peptides

Epithalon: Synthetic version of epithalamin, studied for telomerase activation

GHK Cu: Copper peptide studied for skin remodelling and wound healing

NAD+: While technically a coenzyme, NAD+ precursors are studied for cellular energy and longevity

MOTS c: Mitochondrial derived peptide studied for metabolic regulation

Cosmetic Peptides

Snap 8: Studied for its effects on muscle contraction related to expression lines

GHK Cu: Also falls into this category for its skin related research applications

Sexual Health Research Peptides

PT 141 (Bremelanotide): Melanocortin receptor agonist studied for sexual function

Kisspeptin: Studied for its role in reproductive endocrinology

Conclusion

The diversity of peptide categories reflects the breadth of biological processes they influence. As research continues to expand, new categories and subcategories will emerge, further enriching this dynamic field.

All products are for research purposes only. Not for human consumption.

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