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List of Peptides and What They Do: A Complete Guide
More and more scientists are turning to peptide research. There have been a number of advances in solid-phase synthesis and a growing understanding of how short amino acid chains regulate complex biological systems are fueling this growth.
Today, the list of peptides and what they do includes hundreds of distinct compounds. Some are endogenous signaling molecules, and others are precision-engineered synthetic analogs that scientists study in laboratories across many different research branches.
In this guide, we’ll take a look at the major categories of peptides and their primary areas of research.
Or, if you’re interested in bacteriostatic water, check out our page.
Important: Research peptides are manufactured for laboratory use only and are not intended for human consumption, clinical use, or diagnostic purposes. This article is intended to support scientific understanding and does not constitute medical advice.
Table of Contents
What Are Peptides? A Brief Overview
How Peptides Are Categorized in Research
Primary Peptide Classification Axes:
List of Peptides and What They Do
Tissue Repair and Regeneration Peptides
Growth Hormone Secretagogue Peptides
- CJC-1295 (With DAC)
- CJC-1295 (No DAC)/ModGRF 1-29
- AOD9604
- IGF-1 LR3
- Ipamorelin
- Tesamorelin
- Sermorelin
- Fragment 176-191
Neuropeptides and Cognitive Research Peptides
Anti-Aging and Longevity Peptides
Immune and Anti-Inflammatory Research Peptides
Reproductive, Endocrine, and Sexual Health Research Peptides
Emerging Research Peptides: Metabolic and GLP-1 Analog Peptides
Cellular Repair and Bioregulators
Quick-Reference Table: List of Peptides and What They Do by Category
Looking for a Specific Research Peptide?
Frequently Asked Questions
What Are Peptides?
Simply put, peptides are made up of 2 to 50 amino acids, linked together by peptide bonds, and are essentially smaller fragments of proteins. (Proteins are slightly different, being made up of 50 or more amino acids.) Peptides interact with specific receptors in the body, acting as precise molecular messengers, which makes them incredibly valuable for research.
Peptide Structure and Peptide Bonds
Peptides form when amino acids join together through links called peptide bonds. How many amino acids there are depends on the peptide. For example, Sermorelin has 29 amino acids, whereas BPC-157 has 15. The number of amino acids in the chain gives each peptide a unique structure and function, and also determines how the compound is classified:
- Dipeptides: 2 amino acids
- Oligopeptides: 2–12 amino acids
- Polypeptides: 13–50 amino acids
- Proteins: Typically more than 50 amino acids
This seemingly simple arrangement has remarkable biological specificity. Even small changes in the sequence of the amino acids can change how the peptide interacts with receptors or signaling pathways.
Researchers are interested in how studying small changes in the sequence of the amino acids affects the binding of receptors and metabolic activity.
Peptides vs. Proteins
Peptides and proteins may seem similar, but they are distinct molecular classes, with a few differences. The main difference between them is their size. In general, peptides contain fewer than 50 amino acids, whereas proteins are larger and often have more complex three-dimensional structures.
Here’s how their characteristics differentiate below:
| Peptides | Proteins | |
| Size | Typically 2–50 amino acids | Usually more than 50 amino acids |
| Structure | Has a simpler molecular architecture | Complex folded structures |
| Biological Function | Often signaling or regulatory | More structural and functional roles |
| Metabolism | Can break down into amino acids relatively quickly | May have a longer metabolism, depending on the structure |
We noted earlier that peptides are smaller than proteins. Because of this, researchers are interested in investigating how they interact with systems in the body in highly specific ways. They’re great candidates for laboratory synthesis and research.
How Peptides Are Categorized in Research
According to a study in Nature Reviews Drug Discovery, more and more researchers are studying peptides because of advances in processes like the synthesis of peptides.17
Lau and Dunn explain that researchers are more interested in the way that a peptide works rather than in its characteristics alone.2 Studies now classify peptides according to their function.
Primary Peptide Classification Axes:
- Biological Target System: Musculoskeletal, endocrine, CNS, immune, dermal, and metabolic
- Mechanism Class: Secretagogue, receptor agonist, antimicrobial peptide, or signaling fragment
- Origin: Endogenous/naturally occurring, synthetic analog, or bioregulator
Major Categories of Peptides
We’re able to organize the majority of peptides into several major groups based on their function and the system they interact with in the body. There also tends to be an overlap between the categories of peptides, with some having multiple jobs or functions.
| Category | Primary Research Focus | Example Peptides |
| Tissue Repair and Regeneration Peptides | Investigated for interactions with connective tissue, fibroblasts, angiogenesis, and repair signaling pathways | BPC-157, TB-500, GHK-Cu |
| Growth Hormone Secretagogue Peptides | Studied for effects on the GH/IGF-1 axis, endocrine communication, and metabolic signaling | CJC-1295, Ipamorelin, Sermorelin, Tesamorelin |
| Neuropeptides and Cognitive Research Peptides | Examined for roles in neurotransmission, neuroprotection, learning, memory, and circadian biology | Semax, Selank, DSIP, Pinealon |
| Anti-Aging and Longevity Peptides | Researched for mitochondrial function, cellular aging, telomere biology, and energy regulation | Epithalon, SS-31, MOTS-c |
| Immune and Anti-Inflammatory Peptides | Investigated for immune signaling, inflammatory pathways, and barrier function | Thymosin Alpha-1, KPV |
| Reproductive, Endocrine, and Sexual Health Peptides | Studied for reproductive hormone regulation and neuroendocrine signaling | Kisspeptin-10, PT-141, Oxytocin |
| Metabolic and GLP-1 Analog Peptides | Examined for appetite regulation, glucose metabolism, and incretin signaling | Semaglutide, Tirzepatide, Retatrutide |
| Cellular Repair and Bioregulators | Studied for tissue-protective signaling and cellular homeostasis | Ara-290, Melanotan II |
A Quick Note on Purity and Research Standards For Peptides
Because they’re used within scientific study, it’s essential that all research-grade peptides meet rigorous quality standards. Even the smallest impurity could have an effect on the lab results, which affects reproducibility. If you’re studying peptides, look for compounds that have been:
- Verified for a purity of 99% or higher
- Confirmed through HPLC and mass spectrometry
- Screened for contaminants such as endotoxins and lipopolysaccharides (LPS).
Note: When you’re evaluating peptide suppliers, review the available analytical data and manufacturing standards so you can understand how companies are producing the compounds and verifying them.
At Licensed Peptides, we provide Purity Reports, Endotoxin Reports, and Manufacturing Process documentation to prove the quality of our products. We ensure that researchers receive the guidance they need on peptide quality standards and analytical testing.
For researchers preparing different peptide compounds, our peptide calculator provides a quick way to calculate reconstitution and concentration values while standardizing laboratory preparation.
List of Peptides and What They Do
Tissue Repair and Regeneration Peptides
Researchers are interested in studying these peptides because of how they interact with fibroblasts and growth factor signaling pathways – meaning how they may help heal wounds and grow tissue.
It’s important to note that this research is still in its initial stages, and much of what we know about these peptides comes from early laboratory and animal studies.
1. BPC-157
If you’re familiar with this peptide, you may have also heard it referred to as Body Protection Compound-157. It’s a synthetic peptide that’s been derived from a protein fragment originally identified in gastric juice. BPC-157 is popular in the world of research peptides, with extensive discussions ongoing about its involvement in multiple biological systems in preclinical models.
Research suggests that this peptide may have an influence on pathways for nitric oxide (NO) signaling, fibroblast migration, angiogenesis (the formation of new blood vessels), and even growth factor regulation.3
Key Research Areas of BPC-157:
- Tissue biology
- Cellular repair research
- Gastrointestinal mucosal integrity research
- Tendon-to-bone healing models
- Systemic anti-inflammatory signaling studies
Research Note: When we say this peptide is the subject of “extensive discussions,” we mean regarding studies where researchers use animal models. Currently, there’s no large-scale human RCT on BPC-157 that has been published.
Researchers interested in this compound can review the available BPC-157 research peptides offered by Licensed Peptides, including BPC-157 10mg research vials and BPC-157 capsules (250mcg).
2. TB-500 (Thymosin Beta-4 Fragment)
TB-500 is another synthetic peptide that mimics the healing part of the naturally occurring protein Thymosin Beta-4.
Thymosin Beta-4 helps regulate actin, which is a key component of the cellular cytoskeleton that’s responsible for the shape of cells, their movement, and intracellular organization (how components are arranged inside a cell). In fact, evidence suggests that TB-500 may influence actin dynamics and related signaling pathways, which is why it’s being investigated in several areas of regenerative biology and tissue research.4
Key Research Focus Areas of TB-500:
- Cellular migration pathways
- Soft tissue biology
- Angiogenesis research
- Cytoskeletal regulation
- Inflammatory signaling models
Both TB-500 and BPC-157 have overlapping tissue-signaling pathways and regenerative mechanisms, and because of this, researchers often study them together. We offer a research blend that contains both peptides for in vitro protocols: BPC-157 + TB-500 (Thymosin Beta-4) blend.
3. GHK-Cu (Copper Tripeptide)
If you are interested in skincare research, you may have heard of GHK-Cu. This is because it’s one of the most extensively studied compounds among copper peptides, and researchers study it with regard to regenerative medicine and skin biology.
This is a naturally occurring copper-binding tripeptide made up of glycyl-L-histidyl-L-lysine complexed (joined together) with copper ions. Research in BioMed Research International suggests that it may influence extracellular matrix remodeling through pathways associated with collagen, elastin, and glycosaminoglycan synthesis, which is why it’s so famous in the world of skincare.5
Key Research Focus Areas of GHK-Cu:
- Dermal remodeling studies
- Connective tissue biology
- Hair follicle and hair growth research
- Skin elasticity pathways
- Cellular repair signaling
You’ll also find GHK-Cu included in research formulations with BPC-157 and TB-500. Here at Licensed Peptides, we offer BPC-157 + TB-500 + GHK-Cu (Glow Blend) in one 70mg vial.
Growth Hormone Secretagogue Peptides
Growth hormone secretagogues (GHS) interact with the hypothalamic-pituitary axis. Growth hormone controls how our bodies grow and use energy, which is why it’s such an interesting area of study. Many researchers have studied GHSs in endocrine research, with applications spanning GH/IGF-1 axis dynamics and metabolic signaling, as well as adipose tissue biology.
4. CJC-1295 (With DAC)
CJC-1295 with Drug Affinity Complex (DAC) is a synthetic analog of growth hormone-releasing hormone (GHRH). It binds to the receptors of GHRH within the pituitary gland, and the addition of DAC prolongs its circulation time.6 Because it has an extended half-life, researchers are able to study the patterns of sustained growth hormone secretion and downstream GH/IGF-1 axis dynamics over longer experimental periods.
Key Research Areas of CJC-1295 With DAC:
- GH/IGF-1 signaling dynamics
- Hypothalamic-pituitary axis studies
- Endocrine pathway research
- Hormone regulation mechanisms
- Metabolic signaling investigations
Available for research at Licensed Peptides: CJC-1295 (DAC) 5mg.
5. CJC-1295 (No DAC)/ModGRF 1-29
The no-DAC variant of CJC-1295 has a much shorter half-life and has the ability to model more natural GH release patterns, which makes for interesting scientific research. Researchers like to study this peptide along with GHRP compounds in the lab, as it mimics natural biological synergy.
Key Research Areas of CJC-1295 With No DAC:
- Pulsatile endocrine signaling
- Growth hormone-releasing peptide studies
- Hypothalamic-pituitary axis research
- Secretagogue comparisons
You can get research-grade CJC-1295 No DAC to use in the laboratory.
6. AOD9604
A modified fragment, AOD9604 is derived from the C-terminal region of human growth hormone (HGH). Research suggests that it may interact with different pathways, such as adipose tissue signaling pathways, without replicating the profile of full-length growth hormone.7 This means it doesn’t behave like standard HGH, as it ignores other receptors in the body in favor of the ones on fat cells.
Key Research Areas of AOD9604:
- Adipose tissue biology
- Metabolic signaling pathways
- Cellular energy regulation
- Lipid metabolism research
Researchers investigating metabolic peptides often compare research peptides like AOD9604 5mg with related growth hormone fragments.
7. IGF-1 LR3
A long-acting variant of insulin-like growth factor-1, IGF-1 LR3 has modifications in its structure that make it last longer and reduce binding protein interactions. This peptide is useful for studying IGF-related signaling pathways.
Key Research Areas of IGF-1 LR3:
- Skeletal muscle cell differentiation models
- Glucose transport pathways
- Cellular growth signaling
- Endocrine regulation studies
8. Ipamorelin
Ipamorelin is another pentapeptide growth hormone secretagogue that researchers often study alongside the peptide CJC-1295. Developers made it as a selective growth hormone secretagogue with high affinity for ghrelin-related signaling pathways (networks that control appetite and growth hormone release within the body).8
Key Research Areas of Ipamorelin:
- Growth hormone signaling pathways
- Ghrelin receptor interactions
- Endocrine communication
- Secretagogue receptor specificity
Because researchers often study Ipamorelin together with CJC-1295, it’s common to find blends of both in laboratories. Blends such as CJC-1295 No DAC + Ipamorelin help investigators to evaluate these compounds within the same framework.
9. Tesamorelin
Tesamorelin is a synthetic analog of growth hormone-releasing hormone (GHRH), and researchers are interested in studying its effects on endocrine signaling and metabolic regulation. Studies continue to examine its interactions with adipose tissue biology, hormone regulation pathways, and broader metabolic processes.9
Key Research Areas of Tesamorelin:
- Endocrine pathway regulation
- Adipose tissue signaling
- Metabolic research
- Hypothalamic-pituitary axis studies
Interest in Tesamorelin’s role in metabolic and endocrine signaling has led scientists to develop research formulations such as Tesamorelin + Ipamorelin blends, which combine two widely studied growth hormone secretagogues.
10. Sermorelin
Sermorelin is made up of the first 29 amino acids of endogenous GHRH and is one of the most widely studied GHRH analogs in endocrine research.
Key Research Areas of Sermorelin:
- Hypothalamic-pituitary communication
- Endocrine signaling pathways
- Growth hormone regulation mechanisms
- GHRH receptor interactions
You’ll find that sermorelin is structurally similar to endogenous GHRH, which makes it a useful model for studying physiological growth hormone signaling. If you’re investigating this pathway, you’ll notice that this peptide comes in Sermorelin 5mg research vials, commonly used in endocrine and growth hormone signaling studies.
11. Fragment 176-191
Fragment 176-191 represents a specific region of human growth hormone that has been isolated for laboratory investigation. According to Heffernan et al., researchers have investigated this fragment independently from full-length growth hormone because of its distinct biological activity.7
Key Research Areas of Fragment 176-191:
- Adipose tissue biology
- Lipid metabolism pathways
- Metabolic signaling research
- Growth hormone fragment studies
Important: Scientific literature commonly talks about growth hormone secretagogues. However, you shouldn’t interpret research findings as evidence of clinical effectiveness or human-use outcomes without appropriate regulatory approval and supporting clinical data.
Neuropeptides and Cognitive Research Peptides
12. Semax
A synthetic peptide derived from the ACTH(4-10) sequence, Semax was developed as a neuroactive peptide capable of influencing central nervous system signaling pathways. Subsequent research has suggested that Semax may affect brain-derived neurotrophic factor (BDNF) expression and interact with neurotransmitter systems involved in learning, memory, and attention.
Key Research Areas of Semax:
- Neuroprotection studies
- Cognitive function pathways
- Attention and memory research
- Neuroplasticity investigations
- Neurotransmitter regulation
Semax is one of the most frequently researched neuroactive peptides in the lab. Research materials include both Semax 30mg vials and Semax nasal formulations, which reflects the ongoing interest in different delivery approaches.
13. Selank
Selank is a synthetic heptapeptide derived from tuftsin. Sokolov et al. note that scientists investigate Selank for how it interacts with neurotransmitter systems involved in stress-response and behavioral regulation. Research indicates that Selank may interact with GABAergic and serotonergic signaling pathways (serotonin), which is why there’s so much ongoing interest in immune-neural communication and neurobiology research.10
Key Research Areas of Selank:
- Anxiety-model research
- Neurotransmitter regulation
- Stress pathway studies
- Immune-neural crosstalk
Researchers are continuing to evaluate different delivery approaches in laboratory settings, including Selank 10mg vials and Selank nasal formulations.
14. DSIP
A naturally occurring nonapeptide, Delta Sleep-Inducing Peptide (DSIP) was originally isolated from rabbit cerebral venous blood.
Researchers have been investigating DSIP for its potential role in sleep regulation and neuroendocrine signaling, although its precise physiological function remains the subject of ongoing study.
Key Research Areas of DSIP:
- Circadian rhythm regulation
- Neuroendocrine signaling
- Delta-wave sleep biology
- Stress-response pathways
Although many questions remain regarding its biological activity, DSIP continues to attract attention in sleep and neuroendocrine research. Research materials include DSIP 5mg vials, which are commonly used in laboratory investigations of sleep-related signaling pathways.
15. Pinealon
Pinealon is a short bioregulatory peptide that researchers are studying primarily for its interaction with pineal gland biology. Research focus areas include:
- Circadian biology
- Melatonin pathway regulation
- Neurological aging models
- Epigenetic regulation research
Many scientists are interested in Pinealon because of its association with circadian regulation and neuroendocrine function, placing it within a growing category of bioregulatory neuropeptides.
16. Cerebrolysin (P21 Fragments)
Researchers evaluate Cerebrolysin (and its defined peptide fragments – particularly P21) for areas such as neurogenesis, synaptic plasticity, and neuroprotective pathways. You’ll find that P21, a synthetic CNTF (ciliary neurotrophic factor)-derived peptide, is studied in models of neurodegenerative disease and cognitive decline.
Expert Insight: Some hormone peptides primarily target endocrine pathways, but that’s not the case with Cerebrolysin. Researchers evaluate neuroactive peptides because they can influence neurotransmission, neuroprotection, and communication between neural networks.
Anti-Aging and Longevity Peptides
17. Epithalon
Epithalon is a synthetic tetrapeptide that comes from Epithalamin, a naturally occurring peptide complex. Scientists commonly investigate Epithalon for its potential interactions with telomerase activity, melatonin regulation, and cellular aging pathways.
Key Research Areas of Epithalon:
- Telomere biology
- Cellular aging models
- Circadian rhythm research
- Immune-endocrine interactions
Researchers are likely to use Epithalon 10mg vials when investigating aging-related biological pathways.
18. SS-31
SS-31 is a mitochondria-targeting tetrapeptide that interacts with cardiolipin, a phospholipid located within the inner mitochondrial membrane. It was developed to selectively target mitochondria, and researchers investigate it for its potential effects on mitochondrial bioenergetics (how your body gets energy) and oxidative stress pathways.11
Key Research Areas of SS-31:
- Mitochondrial dysfunction research
- Cardiac cellular biology
- Energy production pathways
- Age-related cellular decline studies
Because mitochondrial dysfunction shows up in numerous biological processes, SS-31 is an important compound when it comes to longevity research.
19. MOTS-c
MOTS-c is a mitochondria-derived peptide encoded within mitochondrial DNA rather than nuclear DNA. The discovery of MOTS-c expanded scientific understanding of mitochondrial signaling by demonstrating that mitochondria can produce biologically active peptides involved in metabolic regulation (how the body manages energy).12
Key Research Areas of MOTS-c:
- Metabolic health models
- Exercise biology
- Cellular energy regulation
- Mitochondrial signaling pathways
Currently, MOTS-c is one of the most actively studied mitochondrial peptides. Related research materials include MOTS-c 10mg vials, which scientists like to use for metabolic and mitochondrial investigations.
20. 5-Amino-1MQ
5-Amino-1MQ is technically classified as a small molecule rather than a peptide, but it frequently appears alongside metabolic research compounds. You’ll find that research areas for this peptide include the inhibition of nicotinamide N-methyltransferase (NNMT), an enzyme involved in cellular metabolism and NAD+ regulation.
Key Research Areas of 5-Amino-1MQ:
- Fat cell differentiation studies
- Metabolic tissue research
- NAD+ pathway investigation
- Cellular energy metabolism
21. FoxO4-DRI
You’ll find that FoxO4-DRI is a prominent senolytic peptide that researchers study in longevity and cellular aging models. It selectively induces apoptosis in senescent cells, which are cells that have permanently exited the cell cycle but resist programmed death.
Research into its mechanism has created interest in the fields of aging biology and tissue homeostasis (the state of perfect balance and stability within a specific tissue of the body).
Note: Longevity-related peptide research is currently an emerging field and, because of this, many proposed mechanisms are supported primarily by lab studies, such as in vitro studies and animal models. There needs to be more investigation into this area before we can draw definitive conclusions.
Immune and Anti-Inflammatory Research Peptides
22. Thymosin Alpha-1
Thymosin Alpha-1 is a naturally occurring 28-amino acid peptide originally isolated from thymic tissue. It is one of the most extensively studied immune-related peptides discussed for its role in both innate and adaptive immune responses.
Thymosin Alpha-1 may influence:
- T-lymphocyte activity
- Antigen presentation pathways
- Cytokine signaling
- Innate and adaptive immune communication
Key Research Areas of Thymosin Alpha-1:
- Immune response modulation
- Immune function research models
- Viral immunology models
- Autoimmune pathway investigations
- Inflammatory signaling studies
A pharmaceutical form known as thymalfasin has received approval in certain countries for specific clinical applications, making Thymosin Alpha-1 one of the more extensively characterized peptides in this category.
23. KPV
KPV is a tripeptide derived from the C-terminal region of alpha-melanocyte-stimulating hormone (α-MSH). α-MSH-derived peptides have been investigated for their interactions with inflammatory signaling pathways and immune regulation.13
Key Research Areas of KPV:
- Intestinal barrier biology
- Inflammatory bowel disease models
- Immune-regulatory pathways
- Gastrointestinal and digestive tract research
Because of its relatively small size and targeted signaling profile, KPV remains an active area of investigation in immunology and digestive system research.
Note: Research-grade peptide blends allow investigators to study combinatorial signaling effects using pre-formulated multi-compound preparations. For instance, BPC-157 + TB-500 + GHK-Cu + KPV Klow blend combines four peptides commonly studied across tissue-signaling, connective tissue, immune-regulatory, and inflammatory research applications.
Reproductive, Endocrine, and Sexual Health Research Peptides
24. Kisspeptin-10
Kisspeptin-10 is a biologically active fragment of the larger kisspeptin peptide family. Research by Seminara et al. helped establish kisspeptin signaling as a key regulator of gonadotropin-releasing hormone (GnRH) activity.14 Subsequent studies have continued to investigate Kisspeptin-10 for its role in neuroendocrine communication and reproductive hormone regulation.
Key Research Areas of Kisspeptin-10:
- Hypothalamic-pituitary-gonadal (HPG) axis studies
- Fertility research
- Puberty timing investigations
- Reproductive hormone regulation
Researchers frequently evaluate Kisspeptin-10 when studying the downstream release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH).
25. PT-141
PT-141, also known as Bremelanotide, is a cyclic melanocortin receptor agonist. Research indicates that PT-141 primarily interacts with the melanocortin receptors MC3 and MC4 in the central nervous system. These melanocortin pathways are involved in a wide range of neuroendocrine processes, contributing to continued interest in PT-141 in receptor signaling research.15
Key Research Areas of PT-141:
- Neuroendocrine signaling
- Melanocortin pathway biology
- Sexual behavior research models
- CNS receptor studies
Research-grade PT-141 10mg (10 vials) and PT-141 nasal (30mg) formulations for research use remain distinct from approved pharmaceutical products and should be evaluated according to laboratory-use standards.
26. Oxytocin
Oxytocin is a neuropeptide hormone synthesized in the hypothalamus. Beyond its well-characterized roles in parturition and lactation, research focus has expanded to neuroendocrine studies, prosocial behavior models, and cardiac function research in preclinical settings.16
27. Cagrilintide
Cagrilintide is a long-acting amylin receptor agonist studied in metabolic research models. Research focus includes appetite regulation pathways and the study of metabolic hormone combinatorial signaling, particularly in combination with GLP-1 receptor agonist compounds.
Emerging Research Peptides: Metabolic and GLP-1 Analog Peptides
Glucagon-like peptide-1 (GLP-1) receptor agonists and related multi-receptor analogs have become cornerstones of modern metabolic research. Their mechanisms in insulin secretion, appetite regulation, and adipose tissue signaling have driven an enormous volume of preclinical and clinical investigation.
28. Semaglutide (Research Grade)
Semaglutide is a GLP-1 receptor agonist heavily evaluated in in vitro and animal models studying insulin secretion pathways, appetite suppression mechanisms, and the long-term effects of GLP-1R agonism on pancreatic beta-cell function.
29. Tirzepatide (Research Grade)
A dual GIP and GLP-1 receptor agonist, you’ll likely have heard of Tirzepatide if you’re interested in modern metabolic and endocrine research. The preclinical research surrounding this peptide examines its differential receptor binding kinetics compared to mono-agonist compounds, its effects on adipose tissue remodeling, and its interaction with the incretin system.
Researchers also frequently investigate this compound to examine blood sugar regulation, appetite signaling, and body fat metabolism in models.
A research-grade triple agonist compound, GLP3-R, is available for research into GIP, GLP-1, and glucagon receptor pathways.
30. Retatrutide (Research Grade)
Retatrutide is a newer triple receptor agonist targeting GIP, GLP-1, and glucagon receptors simultaneously. It is actively profiled in preclinical trials examining the additive and synergistic effects of triple agonism on metabolic signaling and represents the current frontier of multi-receptor metabolic research.
Cellular Repair and Bioregulators
31. Ara-290 (Cibinetide)
Ara-290 is a peptide derived from erythropoietin (EPO) that does not stimulate erythropoiesis. Instead, it is studied for its potential interaction with the Innate Repair Receptor (IRR), a tissue-protective receptor distinct from the classic EPO receptor. Research focus includes tissue inflammation mitigation, neuropathy models, and immune repair signaling in laboratory systems.
32. Melanotan II (MT-II)
Melanotan II is a cyclic analog of alpha-MSH studied for its interactions with melanocortin receptors. Research focus spans MC1R-mediated pigmentation pathways, appetite regulation models via MC4R, and autonomic function studies. It is evaluated separately from PT-141 due to its broader receptor binding profile.
Research-grade MTII: Melanotan 2 10mg.
Quick-Reference Table: List of Peptides and What They Do by Category
| Peptide Name | Category | Primary Research Focus | Available Form |
| BPC-157 | Tissue Repair/Signaling | GI mucosal integrity, tendon-to-bone healing, and anti-inflammatory signaling | Vials, Capsules |
| TB-500 | Tissue Repair | Soft tissue healing, angiogenesis, actin regulation, cell movement | Vials |
| GHK-Cu | Structural / Dermal | Dermal wound healing, collagen synthesis, hair follicle and hair growth biology | Vials |
| CJC-1295 (DAC) | GH Secretagogue | GH/IGF-1 axis dynamics, hypothalamic-pituitary signaling | Vials |
| AOD9604 | Metabolic | Adipose tissue biology, lipolytic pathway signaling | Vials |
| MOTS-c | Metabolic / Mitochondrial | AMPK activation, metabolic homeostasis, mitochondrial communication | Vials |
| Epithalon | Anti-Aging / Longevity | Telomere biology, telomerase regulation, circadian function | Vials |
| Semax | Neuropeptide | BDNF upregulation, neuroprotection, cognition models | Nasal / Injectable |
| Selank | Neuropeptide | Anxiety models, GABAergic/serotonergic interaction, immune-neural crosstalk | Nasal / Injectable |
| DSIP | Neuroendocrine | Sleep architecture, circadian rhythm modulation, stress response biology | Vials |
| PT-141 | Reproductive / Endocrine | Melanocortin receptor agonism, CNS sexual behavior models | Vials / Nasal |
| Kisspeptin-10 | Reproductive / HPG Axis | GnRH stimulation, LH/FSH release, fertility research | Vials |
| Thymosin Alpha-1 | Immune | T-lymphocyte activation, cytokine modulation, immune regulatory models | Vials |
| KPV | Immune / Anti-Inflammatory | NF-kB modulation, intestinal barrier function, IBD models | Vials |
| SS-31 | Anti-Aging / Mitochondrial | Mitochondrial membrane stabilization, ROS reduction, cardiac research | Vials |
Looking for a Specific Research Peptide?
Browse Licensed Peptides’ collection of research-grade peptides. We support all our peptides through purity testing and screen them for harmful endotoxins. Every peptide comes with batch-specific quality documentation, so researchers can rest assured that they’re getting high-quality peptides to help create reproducible results.
Explore All Peptides.
Frequently Asked Questions
What Is a Peptide, and How Is It Different From a Protein?
A peptide is basically a short chain of amino acids that are linked by peptide bonds. They typically have fewer than 50 amino acids, and anything longer is considered a protein. This is because proteins are larger and have more complex structures made up of longer amino acid chains. Because a peptide’s size is much smaller, scientists often use them in research to study specific biological pathways and receptor interactions.
Essentially, peptides are “cellular messengers” that pass on important information to the body’s cells. The specific message will depend on the type of peptide, but some examples include: “burn fat” or “repair tissue and lower the inflammation.”
How Many Types of Peptides Are There?
There isn’t actually a fixed number of peptides. So far, researchers have identified thousands of naturally occurring and synthetic peptides.
To make things easier, researchers typically classify peptides by their biological function or target system, such as tissue repair, neuroendocrine signaling, immune regulation, metabolism, and reproductive biology.2
Are Research Peptides the Same as FDA-Approved Peptide Drugs?
No, research peptides are not the same as FDA-approved peptide drugs. Some peptides are available for human consumption, but not research peptides, as those have been manufactured for laboratory and analytical use. In comparison, FDA-approved peptide drugs have undergone extensive clinical testing and regulatory review to ensure they’re safe for human use without severe side effects or adverse effects.
Some compounds share the same peptide sequence as approved medications, but research-grade materials are not pharmaceutical products.
What Are Growth Hormone Secretagogues?
The word “secretagogue” means a substance that stimulates secretion.
Growth hormone secretagogues (GHS) are compounds that stimulate growth hormone-related signaling pathways. Researchers commonly use peptides such as CJC-1295, Ipamorelin, Sermorelin, and Tesamorelin to study the growth hormone (GH) and insulin-like growth factor-1 (IGF-1) axis.
What Does BPC-157 Do in Preclinical Research?
Researchers investigate BPC-157 in preclinical models involving tissue biology, nitric oxide signaling, fibroblast migration, and growth factor pathways.3 Most published research remains limited to laboratory and animal studies.
What Is the Role of Collagen Peptides in Research?
Collagen peptides are frequently studied for their involvement in connective tissue biology and extracellular matrix remodeling. Research has also investigated compounds such as GHK-Cu for their relationship to collagen, elastin, and glycosaminoglycan synthesis.5
What Is DSIP?
DSIP, or Delta Sleep-Inducing Peptide, is a naturally occurring neuropeptide that has been studied for its potential role in sleep regulation, circadian biology, and neuroendocrine signaling. Its precise physiological function remains an active area of research.
What Does 99%+ Purity Mean for Research Peptides?
A purity level of 99% or higher means that at least 99% of the material is made up of the intended peptide sequence. High purity helps reduce experimental variability, which then improves the reliability of your research. A good research peptide supplier will also include data that proves that the batch has been identity tested and screened for endotoxins.
What Is the Current Regulatory Status of Research Peptides in the United States?
Research peptides are not approved drug products and are generally sold for laboratory use only. Reputable suppliers label these compounds as “For Research Use Only” and “Not For Human Consumption.” Researchers should always review current FDA guidance and institutional policies before acquiring or studying peptide compounds.
Conclusion
Peptide science continues to expand across numerous areas of biological research. From tissue-signaling compounds such as BPC-157 and TB-500 to neuroactive peptides like Semax and Selank, researchers now have access to an increasingly diverse collection of tools for investigating cellular communication, endocrine signaling, immune regulation, metabolic function, and neurological processes.
As new compounds emerge and existing mechanisms become better understood, the list of peptides will likely continue to evolve.
For researchers seeking high-purity, research-grade peptides supported by batch testing and quality documentation, Licensed Peptides provides a growing catalog of compounds suitable for laboratory, analytical, and preclinical research applications.
Note: Our research peptides are produced exclusively for laboratory and scientific research purposes.
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