Research Peptides in 2026: A Literature and Documentation Overview

The field of peptide research has continued to expand into 2026. Researchers across disciplines, from biochemistry and cell biology to analytical chemistry, are incorporating synthetic peptides into their in-vitro and preclinical models as tool compounds.

All compounds discussed are for research use only. Not for human consumption.

What Documentation Should a Research Peptide Have?

• HPLC purity data: A chromatogram and integrated purity value from reverse-phase high-performance liquid chromatography (HPLC).
• Molecular identity confirmation: LC-MS confirms molecular weight; FTIR confirms identity by matching the infrared spectrum to a reference.
• Lyophilization: Freeze-dried peptides are more stable for storage and shipping than liquid preparations.
• Published COA: A Certificate of Analysis should be available for the product. All 18 Excalibur Peptides products are third-party tested; each product's COA is published on the COA page.

Frequently Cited Research Peptides in 2026

BPC-157

A 15-amino-acid peptide whose sequence was derived from a protein fraction described in human gastric juice. Examined in published connective-tissue, GI, and neurological research models. View BPC-157.

TB-500 (Thymosin Beta-4 Fragment)

A synthetic fragment of Thymosin Beta-4 examined in published research on actin binding, cell migration and endothelial cell signaling. View TB-500.

GHK-Cu (Copper Peptide)

A naturally occurring tripeptide-copper complex with a published literature on copper coordination chemistry and gene-expression profiling in cultured cells. View GHK-Cu.

Tesamorelin

A synthetic analogue of growth hormone-releasing hormone (GHRH), examined in published research on GHRH receptor signaling and the growth hormone axis. View Tesamorelin.

GHRP-6

A first-generation growth hormone secretagogue and ghrelin receptor (GHS-R1a) agonist, examined in published research on receptor signaling and growth hormone secretion in animal models. View GHRP-6.

MOTS-c

A mitochondria-derived peptide encoded within mitochondrial DNA. Examined in published cell-culture and rodent research on AMPK signaling and mitochondrial-nuclear communication. View MOTS-c.

NAD+

A dinucleotide coenzyme central to cellular redox chemistry and a substrate for sirtuin and PARP enzymes. View NAD+.

Sourcing Considerations

Look for suppliers that publish third-party HPLC data with identity confirmation (LC-MS or FTIR), supply lyophilized material for stability, publish a Certificate of Analysis for each product, and label every product for research use only. All 18 Excalibur Peptides products are third-party tested, and each product's COA is published on the COA page so researchers can review it before ordering.

Frequently Asked Questions

What does "for research use only" mean for a peptide?

It means the peptide is sold solely for in-vitro laboratory research, is supplied with a published third-party COA reporting purity (HPLC) and identity (LC-MS or FTIR), and is not approved or intended for human or veterinary use.

Which research peptides are most studied in 2026?

Among the most frequently studied compounds in 2026 are BPC-157, TB-500, GHK-Cu, Tesamorelin, GHRP-6, MOTS-c, and NAD+.

What should a COA include?

An HPLC chromatogram with the integrated purity value, identity confirmation (LC-MS or FTIR), a sample or reference identifier, and the testing date.

Are all peptides at Excalibur Peptides for research use only?

Yes. Strictly for research use only. Not intended for human consumption.

How should research peptides be stored?

Lyophilized peptides should be stored at -20°C in a dry environment away from light, following standard laboratory procedures.

For research use only — not for human consumption.

Multi-Receptor Agonist Peptides in Receptor Pharmacology Research

Alongside the peptides listed above, synthetic multi-receptor agonists have become a notable topic in receptor pharmacology. These molecules are designed to bind more than one target receptor, which makes them useful tool compounds for studying how related signaling pathways interact in cell-based assays. The receptors involved are the Glucagon-Like Peptide-1 receptor (GLP-1R), the Glucose-Dependent Insulinotropic Polypeptide receptor (GIPR) and the Glucagon Receptor (GCGR), all members of the class B family of G-protein coupled receptors.

Incretin Receptor Signaling in Laboratory Models

GLP-1R and GIPR are G-protein coupled receptors (GPCRs) expressed in several cell types, and both have been characterized extensively in cell-based assays. When activated in relevant cell lines (e.g., pancreatic beta-cell lines, neuronal cells, or transfected HEK293 cells), these receptors trigger a cascade of intracellular events. The canonical pathway involves the activation of adenylyl cyclase, leading to an increase in cyclic AMP (cAMP). This rise in cAMP activates Protein Kinase A (PKA), which then phosphorylates numerous downstream targets, influencing processes like gene transcription, ion channel activity, and exocytosis in a cell-type-specific manner.

Researchers have long used single-receptor agonists to study these receptors in isolation. The published literature has since examined how the pathways interact, which has led to synthetic peptides designed to bind multiple receptors. Two such compounds available for in-vitro laboratory investigation are the dual-receptor agonist glp-2-t and the triple-receptor agonist glp-3-r. Both are used as tool compounds in receptor-level assays, and neither is approved for human use.

In-Vitro Profile of glp-2-t (Dual GIP/GLP-1 Receptor Agonist)

The compound known in research catalogs as glp-2-t is a synthetic linear peptide composed of 39 amino acids. Its sequence is modeled on native GIP but incorporates modifications so that it binds both the GIP receptor and the GLP-1 receptor. Its structure also includes modifications intended to reduce cleavage by the enzyme dipeptidyl peptidase-4 (DPP-4), which is relevant to its stability in experimental systems compared with native incretin peptides.

Mechanism of Action in Cell-Based Assays: In-vitro studies are used to characterize the receptor-level activity of glp-2-t. In assays using cell lines stably transfected to express either human GIPR or human GLP-1R (e.g., HEK293 or CHO cells), receptor activation is quantified with a cAMP accumulation assay, typically read out by HTRF, luminescence or ELISA. By comparing the concentration-response curve of glp-2-t with those of native GIP and native GLP-1 under identical conditions, it is possible to determine its EC50 and maximal response at each receptor. The ratio of those values describes the compound's relative activity at the two receptors, often referred to as its signaling bias.

This dual activity allows researchers to investigate receptor crosstalk. For example, in cell lines expressing both receptors, investigators can compare cAMP accumulation, β-arrestin recruitment and receptor internalization readouts with those produced by separate GIP and GLP-1 reference agonists, applied individually or in combination. Differences between the combined reference agonists and the single dual-receptor peptide can then be examined at the level of each readout.

Analytical Considerations: A 39-residue modified peptide presents its own analytical challenges. Reverse-phase HPLC methods for peptides of this size usually use shallow acetonitrile gradients and elevated column temperatures to sharpen peaks, and related-substance impurities such as deletion sequences or incompletely deprotected species can elute close to the main peak. Electrospray mass spectrometry of a peptide this large produces a series of multiply charged ions that must be deconvoluted to obtain the intact mass, which is then compared with the value calculated from the sequence. Because long, partly hydrophobic peptides adsorb readily to plastic and glass, low-retention tubes and pipette tips are recommended when preparing solutions. Researchers should review the documentation listed on the product page and perform their own identity confirmation where their work requires it. The compound is sold strictly for in-vitro laboratory research and is not approved for human use.

In-Vitro Profile of glp-3-r (Triple GIP/GLP-1/Glucagon Receptor Agonist)

Building upon the dual-receptor concept, the research compound glp-3-r adds a third receptor. It is a synthetic peptide designed to bind three distinct receptors: GIPR, GLP-1R, and the Glucagon Receptor (GCGR). The addition of glucagon receptor activity makes it useful for comparing three receptor systems within a single assay panel. GCGR is expressed at high levels in hepatocytes, which is why hepatocyte-derived cell lines are commonly used in GCGR signaling assays.

Mechanism of Action in Cell-Based Assays: Characterizing the receptor activity of a triple-receptor agonist like glp-3-r requires a panel of in-vitro assays. Similar to glp-2-t, its activity at GIPR and GLP-1R is measured via cAMP accumulation assays in specific receptor-expressing cell lines. To measure GCGR activity, researchers typically use hepatocyte cell lines (e.g., HepG2) or cells transfected with the human GCGR. In these systems, glucagon receptor activation also raises cAMP, and downstream readouts include PKA substrate phosphorylation and CREB reporter activity.

A key aspect of glp-3-r's in-vitro profile is that its relative activity differs across the three receptors, with comparatively lower activity reported at GCGR than at GIPR and GLP-1R. Characterizing this profile properly requires running all three receptor assays side by side, with native GIP, GLP-1 and glucagon as reference agonists, under identical assay conditions. Each assay should report EC50, maximal response and the number of independent replicates, because small differences in cell passage, receptor expression level or assay buffer can shift apparent potency between laboratories.

Documentation and Handling: As with glp-2-t, glp-3-r is a long modified peptide, and the same analytical considerations apply: shallow HPLC gradients, deconvolution of multiply charged ions in electrospray mass spectrometry, and careful attention to adsorption losses when preparing dilute solutions. Repeated freezing and thawing can reduce the effective concentration of a peptide in solution, and published receptor assays often include a carrier protein such as bovine serum albumin to limit adsorption at low concentrations. Researchers should review the documentation listed on the product page and confirm identity independently where their work requires it. Like every compound in the catalog, glp-3-r is sold strictly for in-vitro laboratory research, is not approved for human use, and must not be administered to humans or animals.

A Closer Look at Quality Documentation: Beyond the HPLC Purity Value

The purity value on a Certificate of Analysis (COA) is the most visible number on the document, but it represents the end of a multi-step analytical process. For researchers, understanding the methods behind the COA helps protect the validity and reproducibility of experimental data. A peptide preparation is not just the target molecule; it is a lyophilized powder containing the peptide itself, counter-ions from purification, residual water, and trace impurities from the synthesis. A thorough analytical program aims to characterize all of these components.

The Role of High-Performance Liquid Chromatography (HPLC)

HPLC is the standard technique for estimating the purity of a synthetic peptide. The principle relies on separating components of a mixture based on their differing affinities for a stationary phase (a solid material packed into a column) and a mobile phase (a liquid solvent mixture that is pumped through the column).

• The Process: A small, precisely measured amount of the dissolved peptide is loaded onto the HPLC system by the autosampler. It is carried by the mobile phase into the analytical column. For peptides, reverse-phase HPLC (RP-HPLC) is most common. The stationary phase is hydrophobic (e.g., C18 silica), and the mobile phase is typically a mixture of water and an organic solvent like acetonitrile, with an acid like trifluoroacetic acid (TFA) added to aid in peak sharpness. A gradient is run where the percentage of organic solvent is slowly increased over time.
• Separation and Detection: Peptides with more hydrophobic character will "stick" more strongly to the stationary phase and will take longer to elute from the column. Peptides with more hydrophilic character will elute earlier. As each component exits the column, it passes through a detector, most commonly a UV detector set to a wavelength where the peptide bond absorbs light (typically 214-220 nm).
• The Chromatogram: The output is a chromatogram, a graph of absorbance versus time. An ideally pure sample would yield a single, sharp peak. The time at which the main peak appears is called the retention time. The area under this main peak corresponds to the quantity of the target peptide. Any other peaks represent impurities: these could be deletion sequences (peptides missing an amino acid), truncated sequences, or molecules with incompletely removed protecting groups from the synthesis. Purity is calculated by dividing the area of the main peptide peak by the total area of all peaks in the chromatogram. The chromatogram itself should accompany the reported value on the COA so the integration can be checked.

Confirming Identity with Mass Spectrometry (MS)

While HPLC confirms purity, it does not confirm identity. A peak on a chromatogram only tells you that something is there; it doesn't prove it's the correct peptide. Mass spectrometry confirms that the molecular weight—and therefore the elemental composition—of the peptide is correct. FTIR spectroscopy is the other common identity method: it matches the sample's infrared spectrum to a reference spectrum for the compound.

• Ionization: Before a mass can be measured, the peptide molecules must be converted into gas-phase ions. The two most common techniques for large biomolecules like peptides are Electrospray Ionization (ESI) and Matrix-Assisted Laser Desorption/Ionization (MALDI). In ESI-MS, the peptide solution is sprayed through a high-voltage capillary, creating a fine mist of charged droplets. As the solvent evaporates, the charge density on the droplets increases until individual peptide ions are ejected into the mass analyzer.
• Mass Analysis: The mass analyzer separates these ions based on their mass-to-charge ratio (m/z). A detector then counts the number of ions at each m/z value.
• The Mass Spectrum: The output is a mass spectrum, a graph of ion intensity versus m/z. For an ESI-MS of a peptide, you will typically see a series of peaks, each corresponding to the same peptide molecule carrying a different number of positive charges (e.g., [M+2H]²⁺, [M+3H]³⁺, [M+4H]⁴⁺). Sophisticated software can "deconvolute" this series of peaks to calculate the original, uncharged molecular mass (M) of the peptide. This experimentally determined mass is then compared to the theoretical mass calculated from the peptide's amino acid sequence. A match within a very narrow tolerance (e.g., ± 0.5 Daltons) provides definitive confirmation of identity.

Endotoxin Testing: The Limulus Amebocyte Lysate (LAL) Assay

For researchers conducting cell-based (in-vitro) experiments, peptide purity and identity are not enough. The presence of endotoxins, even at picogram levels, can have a profound impact on experimental outcomes. Endotoxins are lipopolysaccharides (LPS), components of the outer membrane of Gram-negative bacteria. They are potent activators of the innate immune system.

If a peptide preparation is contaminated with endotoxins, applying it to immune cells (like macrophages) or other sensitive cell lines in culture can trigger cytokine release (e.g., TNF-α or IL-6). This cellular response would be due to the endotoxin, not the peptide being studied, leading to confounded data and incorrect conclusions.

• The LAL Test: The standard method for detecting endotoxins is the Limulus Amebocyte Lysate (LAL) assay. This incredibly sensitive test utilizes a clotting factor cascade found in the blood (amebocytes) of the Atlantic horseshoe crab (Limulus polyphemus). The lysate contains enzymes that are activated in a chain reaction by the presence of endotoxin, ultimately leading to the cleavage of a substrate.
• Methodology: In modern chromogenic LAL tests, the peptide sample is incubated with the lysate. If endotoxin is present, the cascade is activated, and an enzyme cleaves a colorless synthetic substrate to produce a colored product (often yellow). The intensity of this color, measured with a spectrophotometer, is directly proportional to the amount of endotoxin in the sample. Values are expressed in Endotoxin Units per milligram (EU/mg). Researchers planning cell-based assays should decide in advance which endotoxin level their system tolerates and confirm whether the COA reports an endotoxin value.

Assessing Peptide Content and Other Residuals

The lyophilized powder in a vial is never pure peptide. It's crucial to account for other components to prepare accurate stock solutions for assays.

• Peptide Content (by Amino Acid Analysis or AAA): This analysis determines the true proportion of peptide in the lyophilized powder by weight. A sample of the peptide is hydrolyzed, breaking it down into its constituent amino acids. The quantity of each amino acid is then measured (typically by HPLC). By comparing the measured amino acid ratios and quantities to the theoretical sequence, the exact amount of peptide in the original weighed powder can be calculated. The remaining mass consists of moisture and counter-ions, so net peptide content is commonly well below the gross weight of the powder. This value is critical for calculating precise concentrations for experiments.
• Water Content (Karl Fischer Titration): Lyophilized peptides are hygroscopic and will always contain some residual water. Karl Fischer titration is a highly accurate method to quantify this. The test involves a coulometric or volumetric titration based on the reaction of iodine with water. Knowing the water content is essential for calculating the net peptide content.
• Residual Solvents (Gas Chromatography - GC): Solvents like acetonitrile, ether, and acetic acid are used during peptide synthesis and purification. While most are removed during lyophilization, trace amounts can remain. Gas chromatography is used to test for these. A sample is heated, the volatile solvents enter a gaseous mobile phase, and are separated in a column before being detected. This ensures that no residual solvents are present at levels that could interfere with laboratory experiments.

Handling Lyophilized Peptides in the Laboratory

A peptide is most stable in its lyophilized state; once it is in solution, hydrolysis, oxidation and adsorption to surfaces all proceed faster. That is why the sealed vial is kept at the storage temperature listed on the product page, protected from light and moisture, and why repeated freeze–thaw cycles are avoided. A cold vial should reach room temperature before it is opened, so that atmospheric moisture does not condense on the powder.

Solution preparation: Excalibur Peptides does not publish preparation instructions. Laboratories choose solvents, concentrations and handling according to their own validated standard operating procedures, the published literature for the compound and the net content reported on the Certificate of Analysis, and record the solvent, its lot and the date in their methods.

Sequence Features That Affect Stability

• Oxidation: Residues such as Cysteine (C), Methionine (M) and Tryptophan (W) are susceptible to oxidation, which can appear on an HPLC trace as additional peaks close to the main peak.
• Deamidation and Aspartimide Formation: Sequences containing Asparagine (N) or Aspartic Acid (D) can deamidate or form aspartimide, producing related substances with a small mass shift that LC-MS can detect.
• Adsorption: Hydrophobic peptides adsorb readily to glass and plastic surfaces, one reason measured concentrations in dilute solutions can differ from nominal ones.

Comparative Overview of Key Research Peptides

The selection of a peptide for a research project depends entirely on the biological system and pathway being investigated. Different peptides offer distinct mechanisms of action and are suited for different areas of study. The table below provides a high-level comparison of several prominent compounds available for in-vitro research, highlighting their primary research applications and molecular characteristics. This information is intended to guide researchers in selecting the appropriate tools for their experiments. All compounds are for laboratory and research use only.

Expanded Frequently Asked Questions (FAQ)

What is the difference between peptide salt forms (e.g., Acetate vs. HCl)?

During the final purification step of peptide synthesis (RP-HPLC), an acid is used in the mobile phase. Trifluoroacetic acid (TFA) is very common, but it can be cytotoxic in some sensitive in-vitro assays. Therefore, a "salt exchange" procedure is often performed to replace the TFA ions with a more biocompatible counter-ion, like acetate or hydrochloride (HCl). The resulting peptide is supplied as an acetate or HCl salt. For most general research applications, the salt form does not significantly impact the peptide's activity, but for sensitive cell culture experiments, acetate is often preferred over residual TFA. The Certificate of Analysis should specify the counter-ion.

Why does the peptide powder volume look different between vials of the same weight?

The lyophilized peptide in a vial is a dry, fluffy "cake" or powder. Its apparent volume can vary significantly due to differences in the lyophilization (freeze-drying) process parameters, such as the freezing rate and the length of the drying stage. A vial that was flash-frozen might produce a more voluminous, porous cake than one that was slowly frozen, even if they both contain the exact same mass of peptide. This is purely a physical difference in appearance and does not reflect a difference in the actual amount of peptide material. Researchers should always rely on the mass specified on the vial label and COA, not the visual size of the powder.

What does the 'peptide counter-ion' mentioned on a COA represent?

Peptides are composed of amino acids, which have acidic and basic groups. Therefore, the overall peptide molecule carries a charge at neutral pH. To balance this charge and form a stable, solid salt, oppositely charged ions (counter-ions) from the buffers used during synthesis and purification associate with the peptide. For instance, basic residues like Lysine will be associated with a negative counter-ion like acetate (CH₃COO⁻) or trifluoroacetate (CF₃COO⁻). The mass of these counter-ions contributes to the total weight of the powder in the vial but is not part of the peptide itself. This is why the net peptide content is always lower than the gross weight of the powder.

How does third-party testing differ from a supplier's in-house QC?

In-house Quality Control (QC) is the first line of analysis, performed by the manufacturer or supplier themselves. Third-party testing involves sending a sample to an independent laboratory that has no affiliation with the supplier. This external lab performs its own analysis (typically HPLC for purity, plus LC-MS or FTIR for identity) to check the supplier's in-house findings. This practice provides an independent check of purity and identity. All 18 Excalibur Peptides products are third-party tested, and each product's COA is published on the COA page, so researchers can review the data before ordering.

How should researchers interpret small differences in HPLC purity values?

Small differences in a reported purity value often reflect the analytical method rather than the material itself. Integration settings, gradient length, column chemistry and detection wavelength can all shift the calculated value slightly between runs or between laboratories. For most general research applications, minor related impurities (e.g., deletion sequences) present at low levels are unlikely to change the interpretation of an assay. However, for especially sensitive work, such as crystallographic studies or high-throughput screening where any confounding variable must be eliminated, researchers may set their own acceptance specification in advance and request the chromatogram to confirm it. The key is to compare values only when they were generated with the same method.

What is the significance of the 'Sequence' field on a Certificate of Analysis?

The 'Sequence' field provides the one-letter or three-letter amino acid code for the peptide, listed from the N-terminus to the C-terminus. This is the primary identity of the molecule. Researchers must cross-reference this sequence with their intended research target to ensure they have received the correct compound. For example, verifying the sequence Gly-L-His-L-Lys confirms the peptide is GHK, and comparing a long sequence to the known structure of glp-2-t confirms its identity. It is a critical piece of information for validating the research material.

Why does frozen storage before shipping matter, particularly for certain peptides?

Some lyophilized peptides are more sensitive to heat and humidity than others. Peptides containing residues like Cysteine, Methionine, Tryptophan, Asparagine, and Glutamine are more prone to degradation (oxidation, deamidation) if exposed to heat or humidity. Making material in fresh batches and holding it frozen until the day it ships limits its time at elevated temperature; Excalibur keeps every product at -10 °F until it ships.

What is a 'stapled' or 'cyclized' peptide and how does it differ from a linear one?

A linear peptide is a straight chain of amino acids. A cyclized peptide is one where the chain is linked back on itself, forming a ring. This can be a head-to-tail cyclization or a linkage via a disulfide bond between two cysteine residues. A "stapled" peptide is a specific type of constrained peptide where a synthetic chemical linker (the "staple") is used to lock an alpha-helical secondary structure into place. Both cyclization and stapling are strategies used in peptide design to increase stability against enzymatic degradation and to pre-organize the peptide into a defined conformation, which can change receptor binding affinity in in-vitro assays.

Glossary of Technical Terms

• Agonist: A molecule that binds to a receptor and activates it, producing a biological response.
• Aliquot: A portion of a whole; in the lab, refers to dividing a larger volume of a solution (e.g., a peptide stock) into smaller, single-use volumes to prevent contamination and degradation from repeated handling or repeated freezing and thawing.
• cAMP (Cyclic Adenosine Monophosphate): A second messenger molecule, crucial for intracellular signal transduction. Its production is often a key indicator of GPCR activation by peptide agonists like GLP-1.
• Dalton (Da): A unit of mass used to express atomic and molecular weights. It is defined as one-twelfth the mass of a carbon-12 atom. Also known as the atomic mass unit (amu).
• Endotoxin: A lipopolysaccharide (LPS) from the outer membrane of Gram-negative bacteria. A common and potent contaminant that can interfere with in-vitro cell-based experiments.
• G-protein Coupled Receptor (GPCR): A large family of transmembrane receptors that sense molecules outside the cell and activate internal signal transduction pathways, often via intermediary G-proteins. The receptors for GLP-1, GIP, and Glucagon are all GPCRs.
• HPLC (High-Performance Liquid Chromatography): An analytical chemistry technique used to separate, identify, and quantify each component in a mixture. It is the standard method for estimating peptide purity.
• Identity: In peptide chemistry, refers to the confirmation that a synthetic peptide is the stated compound. Verified by mass spectrometry (LC-MS), which checks molecular weight, or by FTIR, which matches a reference spectrum.
• In-vitro: Performed or taking place in a test tube, culture dish, or elsewhere outside a living organism. Refers to experiments conducted in a controlled laboratory setting (e.g., on isolated cells).
• Incretin: A class of gut-derived peptide hormones that act on class B G-protein coupled receptors. The primary incretins studied in laboratory models are GLP-1 and GIP.
• Lyophilization: A freeze-drying process used to remove water from a product. It involves freezing the material and then reducing the surrounding pressure to allow the frozen water to sublimate directly from the solid phase to the gas phase. It makes peptides stable for storage and shipping.
• Mass Spectrometry (MS): An analytical technique that measures the mass-to-charge ratio of ions. It is used to definitively confirm the molecular weight and thus the identity of a peptide.
• Preclinical: Refers to laboratory research, including in-vitro studies and animal model research.
• Purity: The proportion of a sample that is the desired compound. For research peptides, this is estimated by HPLC peak area and reported on the COA.
• Stock Solution: A concentrated solution of a compound, prepared from the dry powder in a suitable solvent, from which working dilutions are made for an assay.

Selected References

• Holst, J. J. (2007). The physiology of glucagon-like peptide 1. Physiological Reviews, 87(4), 1409-1439. (Referenced for incretin receptor background).
• Baggio, L. L., & Drucker, D. J. (2007). Biology of incretins: GLP-1 and GIP. Gastroenterology, 132(6), 2131-2157. (Referenced for incretin receptor background).
• Sikirić, P., Seiwerth, S., Rucman, R., et al. (2014). Current Pharmaceutical Design, 20(7), 1126-1135. (Referenced for BPC-157 context).
• Goldstein, A.L., Hannappel, E., Kleinman, H.K. (2007). Cellular and Molecular Life Sciences, 64(18), 2419-2424. (Referenced for general Thymosin Beta-4 context).
• Pickart, L., & Margolina, A. (2018). International Journal of Molecular Sciences, 19(7), 1987. (Referenced for GHK-Cu context).
• Lee, C., Zeng, J., Drew, B. G., et al. (2015). Cell Metabolism, 21(3), 443-454. (Referenced for MOTS-c context).

For Research Use Only. All compounds and information provided by Excalibur Peptides are intended strictly for in-vitro laboratory research and development purposes. These products are sold as research chemicals and are not approved by the FDA for human or veterinary use. They are not intended for any form of human or veterinary use, consumption, or application. The information presented here is for educational purposes for qualified researchers and is based on preclinical and scientific literature. It does not constitute an endorsement of any particular research application or experimental method. Any questions regarding our research materials can be directed to our support team at info@excaliburpeptides.com.