What Are Research Peptides?
Peptides are short chains of amino acids — the same building blocks that make up proteins. Where proteins can be hundreds or thousands of amino acids long, peptides typically consist of between 2 and 50 amino acids linked by peptide bonds. This smaller size gives them a distinct advantage in research contexts: they tend to interact with specific biological targets with a high degree of precision.
In the human body, peptides function as signalling molecules. They carry instructions between cells, regulate hormone release, mediate immune responses, and play a role in tissue maintenance and repair. Many of the body’s most important biological processes — from growth and metabolism to inflammation and cognition — are governed at least in part by endogenous peptides.
Research peptides are synthetic analogues of these naturally occurring compounds. They are produced in controlled laboratory conditions, typically via solid-phase peptide synthesis (SPPS), and are used in scientific research to study how specific peptide sequences interact with biological systems. Research into these compounds spans cell biology, endocrinology, neuroscience, immunology, and regenerative medicine.
Important notice: All compounds listed in this encyclopedia are sold strictly for in vitro laboratory and scientific research purposes. They are not approved for human use, are not medicines, and should not be interpreted as such.
Compound Profiles
BPC-157
Category: Tissue Repair
Full name: Body Protection Compound-157
Sequence: Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val (15 amino acids)
BPC-157 is a synthetic pentadecapeptide derived from a sequence found in human gastric juice. It has been the subject of substantial research interest due to its apparent role in tissue and wound healing processes.
Mechanism of action: Research suggests BPC-157 promotes angiogenesis — the formation of new blood vessels — through upregulation of vascular endothelial growth factor (VEGF). It appears to interact with the nitric oxide (NO) system and has demonstrated modulatory effects on several growth factor pathways including EGF and FGF. Studies in cell cultures and animal models have investigated its effects on tendon, ligament, muscle, bone, and gastrointestinal tissue.
Research context: The majority of published BPC-157 research has been conducted in rodent models. Studies have investigated its potential in models of tendon injury, inflammatory bowel conditions, and nerve damage. Research into its systemic tolerability profile is ongoing. Human clinical trials remain limited as of 2025.
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TB-500
Category: Tissue Repair
Full name: Thymosin Beta-4 (synthetic fragment)
Note: TB-500 is a synthetic analogue of the naturally occurring peptide Thymosin Beta-4
Thymosin Beta-4 is an endogenous peptide found in virtually all human and animal cells. It plays a central role in the organisation of actin — a structural protein essential to cell movement and shape. TB-500 is a synthetic fragment corresponding to the active region of this molecule.
Mechanism of action: TB-500’s primary mechanism involves binding to actin monomers (G-actin), which promotes cell migration and proliferation. This actin-sequestering activity is understood to be central to its role in wound healing and tissue repair processes. It has also been shown in research to have anti-inflammatory properties and to promote differentiation of stem cells.
Research context: Research has investigated TB-500 in models of cardiac injury, wound healing, and corneal regeneration. It has been studied in the context of hair follicle cell migration and has shown activity in central nervous system repair models. Its stability and water solubility make it a commonly used compound in tissue repair research.
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BPC-157 / TB-500 Combination
Category: Combination Products
This combination pen delivers both BPC-157 and TB-500 in a single formulation. The two peptides are among the most well-researched compounds in tissue repair science and are frequently studied together due to their complementary mechanisms — BPC-157’s influence on angiogenesis and growth factor signalling pairing with TB-500’s actin-binding and cell migration activity.
Research context: Combination studies examining BPC-157 and TB-500 together are an area of growing interest, with researchers exploring whether the two compounds produce additive or synergistic effects in tissue repair models.
View the BPC-157 / TB-500 10mg Combination Pen →
Ipamorelin
Category: Growth Hormone
Type: Growth hormone secretagogue (GHS) / Ghrelin receptor agonist
Ipamorelin is a synthetic pentapeptide and selective growth hormone secretagogue. It is one of the most studied compounds in the ghrelin receptor agonist class due to its selectivity profile.
Mechanism of action: Ipamorelin binds to the ghrelin receptor (GHS-R1a) in the pituitary gland, stimulating the pulsatile release of growth hormone (GH). Unlike earlier-generation secretagogues, ipamorelin is highly selective — research demonstrates it produces minimal effect on cortisol, prolactin, or ACTH release at standard doses, making it a useful research tool for studying isolated GH axis activity.
Research context: Ipamorelin has been investigated in studies examining growth hormone deficiency, body composition, bone density, and gut motility. Its clean selectivity profile has made it a popular reference compound in GHS research. It is frequently studied alongside GHRH analogues (see CJC-1295).
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CJC-1295 No DAC
Category: Growth Hormone
Full name: CJC-1295 without Drug Affinity Complex
Type: Growth hormone releasing hormone (GHRH) analogue
CJC-1295 No DAC is a synthetic analogue of growth hormone releasing hormone (GHRH), the endogenous peptide responsible for stimulating GH secretion from the pituitary. The “No DAC” designation refers to the absence of a drug affinity complex, giving this version a shorter half-life than the DAC variant.
Mechanism of action: CJC-1295 No DAC binds to GHRH receptors on pituitary somatotrophs, stimulating GH release. Because it acts on a different receptor to ghrelin-mimetics like ipamorelin, the two compounds are often studied in combination to examine synergistic effects on the GH axis.
Research context: Research has examined CJC-1295 No DAC in the context of GH pulse amplitude, IGF-1 levels, and metabolic parameters. Its shorter half-life compared to the DAC version makes it preferable in research designs requiring more controlled pulsatile GH release.
View the CJC-1295 No DAC 10mg Research Pen →
Ipamorelin / CJC-1295 No DAC Combination
Category: Combination Products
This combination pen delivers both ipamorelin and CJC-1295 No DAC. The combination is one of the most frequently studied pairings in growth hormone research, exploiting the synergy between GHRH receptor stimulation (CJC-1295) and ghrelin receptor stimulation (ipamorelin) to produce amplified and more physiologically natural GH release.
Research context: Studies examining this combination have looked at GH pulse frequency and amplitude, IGF-1 production, and downstream metabolic and anabolic parameters.
View the Ipamorelin / CJC-1295 No DAC Combo Pen →
Tesamorelin
Category: Growth Hormone
Full name: Tesamorelin
Type: GHRH analogue
Tesamorelin is a stabilised synthetic analogue of the full 44-amino-acid human GHRH sequence. It is one of the more clinically advanced GHRH analogues, having received FDA approval in the United States for a specific HIV-related lipodystrophy indication — making it notable among research peptides for its level of human clinical study.
Mechanism of action: Tesamorelin binds to pituitary GHRH receptors, stimulating pulsatile GH secretion and downstream IGF-1 production. Its structural modifications relative to endogenous GHRH improve metabolic stability.
Research context: Published human clinical trial data on tesamorelin covers visceral adiposity, cognitive function in older adults, and cardiovascular risk markers. This relatively robust clinical dataset makes it a valuable compound in translational research contexts.
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IGF-1 LR3
Category: Growth Factors
Full name: Insulin-like Growth Factor 1 — Long Arg3 variant
IGF-1 LR3 is a synthetic, extended-half-life variant of Insulin-like Growth Factor 1 (IGF-1). It contains a 13-amino-acid extension at the N-terminus and an arginine substitution at position 3, which reduces its binding affinity for IGF-binding proteins (IGFBPs) and extends its active half-life substantially compared to native IGF-1.
Mechanism of action: IGF-1 binds to the IGF-1 receptor (IGF1R), a tyrosine kinase receptor that activates the PI3K/Akt and MAPK signalling pathways. These pathways regulate cell proliferation, differentiation, survival, and protein synthesis. IGF-1 is a primary mediator of GH’s anabolic effects and plays a central role in muscle, bone, and connective tissue biology.
Research context: IGF-1 LR3 is widely used in cell culture research as a growth factor supplement. Research applications include muscle cell biology, metabolic studies, and investigations into the GH/IGF-1 axis.
View the IGF-1 LR3 1mg Research Pen →
GHK-Cu
Category: Growth Factors / Tissue Repair
Full name: Copper peptide GHK-Cu (Glycyl-L-histidyl-L-lysine : copper)
GHK-Cu is a naturally occurring copper-binding tripeptide found in human plasma, urine, and saliva. Plasma concentrations decline significantly with age, a fact that has driven research interest in its role in biological ageing and tissue maintenance.
Mechanism of action: GHK-Cu is a pleiotropic compound with a wide range of documented biological activities in research. It has been shown to stimulate collagen, elastin, and glycosaminoglycan synthesis; promote wound healing and tissue remodelling; activate antioxidant pathways; and modulate gene expression across hundreds of genes related to inflammation, DNA repair, and nervous system function. Its copper-chelating properties are believed to be central to many of its activities.
Research context: GHK-Cu has been studied extensively in wound healing, skin biology, and anti-ageing research. It has also been investigated for neuroprotective and anti-inflammatory properties. A significant volume of the published literature focuses on topical applications, though systemic research is ongoing.
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Epithalon
Category: Longevity & Anti-Ageing
Full name: Epitalon (Epithalamin fragment)
Sequence: Ala-Glu-Asp-Gly (tetrapeptide)
Epithalon is a synthetic tetrapeptide derived from epithalamin, a polypeptide extract from the pineal gland. It was developed and studied extensively by Russian researcher Vladimir Khavinson at the St. Petersburg Institute of Bioregulation and Gerontology, and represents one of the more studied compounds in the longevity peptide space.
Mechanism of action: Epithalon’s primary mechanism under investigation involves telomerase activation — the enzyme responsible for extending telomeres, the protective caps on chromosomes that shorten with each cell division. Research has also examined its effects on melatonin production, pineal gland function, antioxidant activity, and circadian rhythm regulation.
Research context: Published research on Epithalon spans cell culture studies, animal lifespan models, and a body of human clinical work from Russian research institutes. Studies have examined its effects on biomarkers of ageing, immune function, and cancer incidence in aged animal populations.
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Thymosin Alpha-1
Category: Longevity & Anti-Ageing
Full name: Thymosin Alpha-1 (Tα1)
Thymosin Alpha-1 is a 28-amino-acid peptide naturally secreted by the thymus gland. It is one of the most extensively studied immunomodulatory peptides and has received regulatory approval in over 35 countries for specific infectious disease and oncology indications — giving it one of the most substantial clinical evidence bases of any peptide in this category.
Mechanism of action: Thymosin Alpha-1 modulates both innate and adaptive immune responses. It acts on dendritic cells, T-cells, and natural killer (NK) cells, promoting differentiation and activation. It upregulates toll-like receptor expression and stimulates cytokine production including interferon-α and interleukin-2. It also exhibits antioxidant and anti-inflammatory activity.
Research context: Published research covers HIV, hepatitis B and C, cancer immunotherapy, sepsis, and COVID-19. Thymalfasin — the pharmaceutical grade version — is approved and marketed in several countries. This established clinical literature makes Thymosin Alpha-1 a valuable reference compound in immunology research.
View the Thymosin Alpha-1 5mg Research Pen →
MOTS-c
Category: Metabolic / Longevity & Anti-Ageing
Full name: Mitochondrial Open Reading Frame of the 12S rRNA-c
MOTS-c is a mitochondria-derived peptide (MDP) — a relatively recently discovered class of signalling molecules encoded within mitochondrial DNA rather than nuclear DNA. It was first identified in 2015, making it one of the newer compounds in this encyclopedia.
Mechanism of action: MOTS-c translocates to the nucleus under stress conditions and activates AMPK (AMP-activated protein kinase), a master metabolic regulator. This drives glucose uptake, fatty acid oxidation, and mitochondrial biogenesis. Research has also identified roles in regulating the folate cycle and methionine metabolism. Circulating levels of MOTS-c decline with age and obesity, implicating it in metabolic ageing.
Research context: Research has examined MOTS-c in models of obesity, type 2 diabetes, physical performance, and ageing. Animal studies have demonstrated effects on insulin sensitivity, body composition, and lifespan extension. Its mitochondrial origin and AMPK-activating mechanism make it of significant interest in metabolic disease research.
Available as a 20mg or 40mg research pen.
NAD+
Category: Mitochondrial / Longevity & Anti-Ageing
Full name: Nicotinamide Adenine Dinucleotide
NAD+ is a coenzyme found in every living cell. It is central to cellular energy metabolism and plays an essential role in redox reactions, DNA repair, gene expression regulation, and circadian rhythm maintenance. NAD+ levels decline with age, a finding that has generated considerable scientific interest.
Mechanism of action: NAD+ is required by sirtuins (SIRT1–7), a family of protein deacylases involved in longevity signalling, DNA repair, and metabolic regulation. It is also consumed by PARP enzymes in DNA strand-break repair and by CD38 in calcium signalling. By acting as an electron carrier in the mitochondrial electron transport chain, NAD+ is directly tied to ATP production efficiency.
Research context: Research into NAD+ and its precursors (NMN, NR) has grown substantially over the past decade. Studies have examined its role in ageing, neurodegeneration, metabolic disease, and mitochondrial dysfunction. Direct NAD+ administration is studied alongside precursor compounds to assess bioavailability and downstream pathway effects.
Available in 500mg and 1000mg research pen formats.
Glutathione
Category: Mitochondrial / Longevity
Full name: L-Glutathione (reduced form)
Sequence: γ-Glu-Cys-Gly (tripeptide)
Glutathione is the body’s master antioxidant — a tripeptide synthesised in virtually every cell and present at millimolar concentrations in the cytoplasm. It is central to cellular redox homeostasis and is one of the most studied molecules in biochemistry.
Mechanism of action: Glutathione neutralises reactive oxygen species (ROS) and reactive nitrogen species by donating electrons. In doing so, it converts to its oxidised form (GSSG), which is recycled back to the reduced form (GSH) by glutathione reductase. Beyond direct ROS scavenging, glutathione participates in Phase II detoxification, immune cell function, protein folding, and the regulation of gene expression. Intracellular GSH levels are a key indicator of cellular health and oxidative stress burden.
Research context: Glutathione depletion is associated with ageing, neurodegenerative disease, liver disease, and mitochondrial dysfunction. Research has examined exogenous glutathione administration via multiple routes, with a focus on bioavailability and tissue-level effects on oxidative stress markers.
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Kisspeptin
Category: Hormonal
Also known as: Metastin
Kisspeptin is an endogenous neuropeptide encoded by the KISS1 gene. It is a master regulator of the hypothalamic-pituitary-gonadal (HPG) axis and plays a critical gatekeeping role in reproductive endocrinology. The peptide was originally identified as a metastasis suppressor before its role in reproduction was discovered.
Mechanism of action: Kisspeptin binds to the KISS1 receptor (GPR54) on GnRH neurons in the hypothalamus, triggering pulsatile release of gonadotropin-releasing hormone (GnRH). This downstream cascade drives LH and FSH secretion from the pituitary, and ultimately gonadal sex hormone production. Kisspeptin neurons are responsive to feedback from oestrogen, testosterone, and metabolic signals, making kisspeptin a central integrator of reproductive and metabolic status.
Research context: Kisspeptin has been studied in the context of reproductive disorders, puberty timing, hypothalamic amenorrhoea, and the relationship between energy balance and fertility. Human clinical trials have been conducted at Imperial College London and elsewhere. It is also under investigation for its role in sexual aversion and social behaviour.
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Melanotan 2
Category: Melanocortin
Also known as: MT-II
Type: Non-selective melanocortin receptor agonist
Melanotan 2 is a cyclic synthetic analogue of α-MSH (alpha-melanocyte-stimulating hormone), an endogenous peptide involved in pigmentation, appetite, and sexual function.
Mechanism of action: Melanotan 2 binds to melanocortin receptors (MC1R–MC5R). MC1R activation triggers eumelanin production in melanocytes, producing skin and hair pigmentation. MC3R and MC4R activation has been linked to appetite suppression and sexual arousal effects respectively. Its non-selectivity across receptor subtypes is important context for interpreting research findings.
Research context: Melanotan 2 has been studied in models of photoprotection, sexual dysfunction, obesity, and skin pigmentation disorders. Its broad receptor profile has made it both a useful pharmacological tool and a compound of ongoing study for its complex constellation of effects.
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Semax
Category: Cognitive & Neurological
Derived from: ACTH(4-7) fragment
Semax is a synthetic heptapeptide analogue of the adrenocorticotropic hormone (ACTH) fragment 4-7, with added Pro-Gly-Pro stabilisation. It was developed in Russia and has been approved there as a pharmaceutical for neurological applications, providing a meaningful body of human research data.
Mechanism of action: Semax exerts neuroprotective effects through multiple pathways. Research indicates it increases brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) expression, promotes neuroplasticity, and modulates serotonin and dopamine neurotransmitter systems. It demonstrates anti-inflammatory effects in brain tissue and has been shown to reduce oxidative stress in neuronal cells.
Research context: Studies have examined Semax in models of stroke, cognitive impairment, ADHD, and optic nerve disease. Clinical data from Russian medical literature includes trials in ischaemic stroke recovery. Its BDNF-upregulating properties are of particular interest in neuroregeneration research.
View the Semax 20mg Research Pen →
Selank
Category: Cognitive & Neurological
Derived from: Tuftsin
Selank is a synthetic analogue of the endogenous immunopeptide tuftsin (Thr-Lys-Pro-Arg), extended with the sequence Pro-Gly-Pro to improve stability. Like Semax, it was developed in Russia and has been studied in clinical contexts.
Mechanism of action: Selank’s primary mechanism involves modulation of the GABAergic system and regulation of GABA-A receptor activity, producing anxiolytic effects comparable to benzodiazepines in research models without the sedative or dependence profile. It also influences expression of BDNF and IL-6, and has demonstrated effects on serotonin transporter activity. Its immunomodulatory parent compound tuftsin contributes an additional layer of immune-relevant activity.
Research context: Research has examined Selank in models of anxiety, depression, and cognitive enhancement. Clinical studies in Russia have investigated it as an anxiolytic with nootropic properties. Its dual mechanism — anxiolytic and neurotrophic — has made it a compound of interest in neuropsychiatric research.
View the Selank 10mg Research Pen →
All compound profiles are provided for educational and research reference purposes only. Information is drawn from publicly available scientific literature. These compounds are not medicines, are not approved for human use, and are sold exclusively for in vitro laboratory research. R&D Peptides does not endorse or encourage use of these compounds outside of legitimate scientific research contexts.
Profile content last reviewed: March 2026
