B7-33 exibits potent anti-fibrotic effects. It is under active research and investigation as a means of reducing fibrosis in acute and chronic diseases like heart failure, lung inflammation, kidney and more. In animal studies, B7-33 has reduced fibrosis by roughly 50%, leading to prolonged survival following injury and offering the first new means of treating heart failure in 20 years. It has been shown to reduce excessive scar formation following cardiac injury. It has also shown promise in the treatment of certain vascular disorders as well as preeclampsia of pregnancy.

Product Usage: This PRODUCT IS INTENDED AS A RESEARCH CHEMICAL ONLY. This designation allows the use of research chemicals strictly for in vitro testing and laboratory experimentation only. All product information available on this website is for educational purposes only. Bodily introduction of any kind into humans or animals is strictly forbidden by law. This product should only be handled by licensed, qualified professionals. This product is not a drug, food, or cosmetic and may not be misbranded, misused or mislabled as a drug, food or cosmetic.

What is B7-33?

B7-33 is a soluble synthesized single chain peptide derived from the larger, naturally occurring protein H2-relaxin. B7-33 retains the anti-fibrotic properties of relaxin without increasing production of cAMP. This peptide stimulates ERK1/2 phosphorylation, promoting matrix metalloproteinase 2 (MMP2) expression and the degradation of extracellular collagen.

B7-33 is one of a number of synthetic peptides derived from the human H2-relaxin protein, which is itself the namesake of a family of four proteins (relaxin, insulin-like peptide 3, H3-relaxin, and insulin-like peptide 5) known as the relaxin proteins. These proteins, which are closely related to insulin, have all been shown to have pleiotropic actions, impacting the musculoskeletal system, cardiovascular system, and reproduction among others[1].

The relaxin family peptides have four endogenous receptors that are divided into two pairs (RXFP1/2 and RXFP3/4). The function of these receptors is outlined as follows:

The relaxin receptors are not just targets for relaxin proteins, however. These receptors can be stimulated by cAMP, orexin, corticotropin-releasing factor (CRF), several insulin-like peptides, and GLP-1. The agonists have been variously shown to have anti-inflammatory, antioxidant, and wound healing properties. These findings led researchers to explore the primary ligand for these receptors, which was identified as relaxin. Research shows that relaxin has all of the properties just mentioned in addition to being a vasodilator, blood vessel growth stimulator, and antihypertrophic. Taken together, these functions given relaxin potent anti-fibrotic properties and have led to the serious investigation of this peptide and its derivatives in the treatment of acute heart failure and other fibrotic disorders[1].

Structures

Sequence: VIKLSGRELVRAQIAISGMSTWSKRSL PubChem CID: 318164840 Synonyms: (B7-33)H2, GTPL9321

B7-33 Research

B7-33 Function

Due to its unique structure, even though B7-33 binds to the RXFP1 receptor with greater affinity than the native H2-relaxin protein, B7-33 preferentially activates the pERK pathway over the cAMP pathway. The pERK pathway is known to play an important role in cell cycle arrest in the G1 phase and has been implicated in a number of diseases including protein-misfolding conditions like Alzheimer’s disease and Crutzfeld-Jacob disease.

By arresting cell cycle progression in cells with RXFP1 receptors, B7-33 can produce a number of effects. It appears that its anti-fibrotic effects, however, are most likely mediated through the ability to stimulate RXFP1-angiotensin II type 2 receptor heterodimering, which activates pERK1/2 signaling and, eventually, leads to increased production of the collagen-degrading enzyme matrix metalloproteinase (MMP) -2. It is important that B7-33 promotes only pERK pathway activation as it is thought that cAMP activation may be responsible for some of the tumor-promoting effects seen with full-sequence H2-relaxin and not seen with B7-33[6].

Ease of Production

One of the advantages of B7-33 over the native H2-relaxin protein is that it does not activate the cAMP pathway but still retains the ability to promote the full anti-fibrotic effects of the parent peptide. This is not, however, the only advantage that B7-33 offers. Just as important among its attributes is the fact that B7-33 is easier to produce. Because B7-33 has less complicated 2D and 3D structures, it is much less laborious to produce a functional B7-33 protein than a full H2-relaxin protein. This ease of production leads to less expensive production as well.

Anti-Fibrotic Properties

Fibrosis, which is to say scarring or unorganized tissue regeneration, is the end state of at least half of all chronic diseases. From cardiovascular disease to lung disease to cirrhosis of the liver, aberrant wound healing (i.e. fibrosis) is one of the primary causes of organ failure. In 2012, H2-relaxin completed phase II clinical trials for the treatment of acute heart failure. The research revealed that H2-relaxin administration leads to immediate vasodilatory effects and reduces the long-term scarring seen following heart damage. This makes H2-relaxin the first new treatment approved for acute heart failure in 20 years[6].

While the benefits of H2-relaxin are robust and significant, there are drawbacks to using the full relaxin protein as a therapeutic agent. Not only is H2-relaxin difficult to produce it can also only be administered via IV injection. Additionally, the full protein has been shown to increase heart rate and promote cancer progression (particularly prostate cancer)[7], [8]. Most of these effects have been traced to the protein’s activation of the cAMP pathway, so an effort was made to reduce cAMP activation. The result of that effort is B7-33.

According to Dr. Akhter Hossain, one of the lead developers of B7-33, the peptide increases MMP-2 production as well as or even slightly more than H2-relaxin does. This, of course, translates into a significant reduction in cardiac fibrosis in rat models of MI-induced heart failure. With the reduced fibrosis comes a concomitant improvement in heart function and thus a reduction in the long-term symptoms and complications of heart failure. Results suggest that B7-33 may reduce overall scarring in the heart, following injury, by approximately 50%. Similar effects were recorded in mouse models of asthma and lung fibrosis.

To further test the benefits of B7-33 over H2-relaxin, Dr. Hossain and his colleagues examined what would happen if B7-33 was given to mice with prostate cancer. As it turns out, B7-33 not only did not promote tumor growth when administered at doses necessary to treat fibrosis, it didn’t even promote tumor growth when given at higher doses than those producing anti-fibrotic effects. This happens because B7-33 works almost exclusively through the pERK pathway and does not stimulate cAMP production.

Blood Vessel Protection

Human relaxin-2 (serelaxin) has been of intense focus in laboratory research for its ability to protect the vasculature against edothelial dysfunction and long-term scarring. Research in mail Wistar rats shows that B7-33 replicates the vasoprotective effects of serelaxin by enhancing bradykinin-mediated endothelium-dependent relaxation in arteries. It appears to do this by boosting endothelium-derived hyperpolarization in certain vascular beds. The selectivity of this molecule in causing vasorelaxtion may make it useful in the treatment of certain cardiovascular conditions as well as preeclampsia of pregnancy[9]. Because it is simpler and more affordable to produce than serelaxin, B7-33 may quickly become the defacto therapeutic option for certain vascular conditions.

B7-33 in Preeclampsia

Preeclampsia is a common complication of pregnancy that leads to high blood pressure and reduced fetal weight. While manageable to a large degree, preeclampsia can be difficult to control and, in some cases, life-threatening to both mother and fetus. In the most extreme cases of preeclampsia, immediate delivery of the baby is necessary, making it a common causes of pre-term delivery. Research, however, suggests that relaxin and thus B7-33 may prove useful in controlling preeclampsia even in severe cases.

The most recent research available suggests that B7-33 likely acts at the RXFP-1 receptor to increase the production of VEGF in cytotrophoblasts. These cells, found in the developing fetus, are critical in helping to establish blood flow between the maternal circulation and the developing fetus. By stimulating VEGF production, B7-33 promotes the growth of blood vessels and thus improves blood supply between mother and child[10].

This same research also reveals that lipidated B7-33 has a much longer in vivo half-life and that lipidation has no impact on the peptides activity[10]. A longer half-life would make B7-33 an even more effective therapeutic and increases the odds that enteral administration can result in therapeutic plasma levels of the protein.

B7-33 in Anti-Fibrotic Materials

One unique area in which B7-33 is finding application, at least in research, is in the production of anti-fibrotic materials or materials that resist the foreign body response. Under normal circumstances, the body reacts to a foreign object by trying to remove it completely. If that cannot be done, then the body will begin to wall off the foreign object, via fibrosis, to isolate it from the body and reduce its ability to cause disease and dysfunction. This is all well and good in the fight against pathogens, but becomes problematic when one wishes to implant a medical device, like a cardiovascular stent for instance, into the body. In these cases, fibrosis can lead to dysfunction or degradation of the implant. In some cases, such as with cardiac stents, fibrosis can lead to artery occlusion, reduced blood supply, and eventually heart attack.

B7-33 offers an ideal coating for use in implants. In one study, the release of B7-33 from the coating of a device reduced fibrotic capsule thickness by nearly 50% over a 6-week trial. Such results are the first step, but open up the possibility of a range of improved implantable medical devices. In fact, the use of B7-33 and similar peptides could preclude the need to use systemic drugs (e.g. plavix or aspirin when cardiac stents are placed) to reduce fibrosis of implanted medical devices, which would make the devices safer and allow them to be implanted in a wider range of patients (e.g.patients with more severe disease)[11].

Summary

B7-33 is a novel peptide with potent anti-fibrotic effects. It is under active research and investigation as a means of reducing fibrosis in acute and chronic diseases like heart failure, lung inflammation, and more. In animal studies, B7-33 has reduced fibrosis by roughly 50%, leading to prolonged survival following injury and offering the first new means of treating heart failure in 20 years.

There is additional interest in using B7-33 to reduce the foreign body response to implanted medical devices. Once again, B7-33 reduces fibrotic capsule formation in implanted devices by approximately 50%, paving the way to new and improved implantable medical devices while also extending the utility and application of existing devices.

B7-33 is not just an anti-fibrotic peptide though. It has other properties, with its ability to reduce blood pressure and protect vasculature being of greatest interest. Studies in animal models of preeclampsia suggest that B7-33 might be a useful tool in treating this difficult-to-manage disease, potentially allowing more women to carry children to term in a manner that is safe for both mother and baby.

Scientific Journal Author

Dr. Hossain is being referenced as one of the leading scientists involved in the research and development of B7-33. In no way is this doctor/scientist endorsing or advocating the purchase, sale, or use of this product for any reason. There is no affiliation or relationship, implied or otherwise, between     peptide Review hub and this doctor. The purpose of citing the doctor is to acknowledge, recognize, and credit the exhaustive research and development efforts conducted by the scientists studying this peptide. Dr. Jean Mazella is listed in [6] under the referenced citations.

B7-33 is a synthetic relaxin-derived research peptide that has generated significant interest in fibrosis biology, cardiovascular research, vascular health, tissue remodeling, and regenerative medicine. Developed from the naturally occurring hormone H2-relaxin, B7-33 was specifically engineered to retain powerful anti-fibrotic activity while minimizing some of the signaling pathways associated with the parent molecule.

As research into fibrosis, cardiac remodeling, vascular dysfunction, and tissue repair expands, researchers frequently compare B7-33 vendors based on purity, testing standards, pricing, supplier reputation, and overall quality.

This B7-33 Vendor Price Comparison Guide helps researchers evaluate suppliers using objective criteria including:

• Product Pricing

• Cost Per Milligram

• Product Purity

• Third-Party Testing

• Certificate of Analysis (COA)

• Vendor Reputation

• Customer Reviews

• Shipping Performance

• Product Availability

• Overall Value

Whether you're seeking the most affordable B7-33 supplier, vendors with extensive laboratory testing, or the highest-rated peptide company, this guide provides a framework for comparing research suppliers.

Explore B7-33 Vendors by Criteria

Most Popular B7-33 Vendors

Compare peptide suppliers frequently selected by fibrosis and cardiovascular researchers.

Highest Reviewed B7-33 Vendors

Discover vendors with strong customer satisfaction and positive marketplace reputations.

Lowest Price B7-33 Vendors

Identify suppliers offering competitive pricing and favorable cost-per-milligram value.

Highest Purity B7-33 Vendors

Review suppliers providing transparent purity verification and batch-level testing.

Best Value B7-33 Vendors

Compare quality standards, testing programs, customer service, and pricing.

Fastest Shipping B7-33 Vendors

Evaluate fulfillment speed, packaging quality, and shipping reliability.

Newly Listed B7-33 Vendors

Explore recently launched peptide suppliers offering B7-33 research products.

What Is B7-33?

Overview

B7-33 is a synthetic single-chain peptide derived from human H2-relaxin, a member of the relaxin peptide family.

Researchers developed B7-33 to preserve the beneficial anti-fibrotic effects of relaxin while preferentially activating specific intracellular signaling pathways associated with tissue remodeling and collagen regulation.

Research involving B7-33 has focused on:

• Fibrosis biology

• Cardiac remodeling

• Lung fibrosis

• Vascular function

• Tissue regeneration

• Wound healing

• Implant biocompatibility

• Pregnancy-associated vascular disorders

Its unique signaling profile has made B7-33 one of the most promising anti-fibrotic peptides currently under investigation.

Molecular Characteristics

Peptide Information

Researchers evaluating B7-33 products should carefully review product specifications and analytical documentation.

Peptide Name

B7-33

Alternative Names

• (B7-33)H2

• GTPL9321

Amino Acid Sequence

VIKLSGRELVRAQIAISGMSTWSKRSL

PubChem CID

318164840

Classification

Relaxin-Derived Synthetic Peptide

Research Category

Anti-Fibrotic & Cardiovascular Research

Parent Molecule

Human H2-Relaxin

Why Researchers Compare B7-33 Vendors

Research reproducibility depends heavily on product consistency and peptide quality.

Supplier differences may include:

• Purity levels

• Manufacturing standards

• Batch consistency

• Stability testing

• Storage conditions

• Product documentation

• Shipping procedures

• Quality-control systems

Choosing suppliers solely on price may overlook critical quality indicators.

How We Compare B7-33 Vendors

Third-Party Laboratory Testing

Independent testing remains one of the strongest indicators of research quality.

Researchers should prioritize vendors that provide:

• Third-party testing

• Batch-specific reports

• Identity verification

• Purity analysis

Certificate of Analysis (COA)

A high-quality COA should contain:

• Batch number

• Testing date

• Purity percentage

• Product identity verification

• Testing methodology

Product Purity

Purity is among the most important metrics for evaluating specialty research peptides.

Higher purity can contribute to greater reliability and experimental reproducibility.

Cost Per Milligram

Comparing only vial prices can be misleading.

Cost Per Milligram Formula

Product Price ÷ Total Milligrams = Cost Per Milligram

This calculation provides a more meaningful comparison between suppliers.

Customer Reviews

Customer feedback often reveals valuable information regarding:

• Product consistency

• Packaging quality

• Shipping performance

• Inventory availability

• Customer support

Vendor Reputation

Established peptide suppliers often demonstrate:

• Strong quality-control standards

• Reliable inventory management

• Transparent testing programs

• Consistent customer satisfaction

Current Research & Evidence

Anti-Fibrotic Research

The primary area of B7-33 research involves fibrosis regulation.

Fibrosis is a pathological process characterized by excessive collagen deposition and abnormal tissue remodeling.

Researchers continue investigating how B7-33 influences:

• Fibroblast activity

• Extracellular matrix turnover

• Collagen degradation

• Scar formation pathways

Relaxin Signaling Research

B7-33 was designed to selectively activate beneficial relaxin-associated pathways while minimizing signaling linked to unwanted effects.

Research has focused on:

• RXFP1 receptor activation

• ERK1/2 signaling

• Matrix remodeling

• Tissue repair biology

These characteristics distinguish B7-33 from full-length H2-relaxin.

Cardiac Research

One of the most active areas of B7-33 investigation involves cardiovascular biology.

Researchers have studied relationships between B7-33 and:

• Cardiac fibrosis

• Post-injury remodeling

• Myocardial function

• Heart-failure pathways

Preclinical findings have generated significant interest in future cardiovascular applications.

Key Findings on B7-33 Research

Collagen Regulation Research

Experimental studies suggest B7-33 influences pathways involved in collagen turnover.

Researchers continue examining effects on:

• Matrix Metalloproteinase-2 (MMP-2)

• Extracellular matrix remodeling

• Connective tissue organization

• Fibrotic tissue regulation

Lung Fibrosis Research

B7-33 has been studied in respiratory research models involving:

• Pulmonary fibrosis

• Chronic lung inflammation

• Airway remodeling

• Lung-tissue repair

Scientists continue investigating how relaxin-derived peptides interact with pulmonary fibrosis pathways.

Vascular Health Research

Research suggests B7-33 may influence vascular signaling and endothelial function.

Areas of interest include:

• Blood-vessel relaxation

• Vascular remodeling

• Endothelial biology

• Circulatory function

These findings have prompted additional investigation into cardiovascular disease models.

Implant & Biomaterials Research

One unique application of B7-33 involves reducing fibrotic responses around implanted medical devices.

Researchers have explored B7-33-containing materials for use in:

• Implant coatings

• Biomedical devices

• Tissue-engineering scaffolds

• Foreign-body response research

Reducing fibrotic capsule formation remains a major challenge in medical-device development.

Pregnancy & Preeclampsia Research

Researchers have investigated B7-33 in experimental models involving:

• Placental vascular function

• Angiogenesis

• VEGF signaling

• Preeclampsia-associated pathways

This remains an emerging area of scientific investigation.

Research Limitations

Most current B7-33 findings originate from:

• Laboratory research

• Cell-culture studies

• Animal models

• Early-stage preclinical investigations

Additional research remains necessary to fully characterize its biological mechanisms and long-term effects.

Research results should not be interpreted as evidence of approved therapeutic applications.

Product Quality & Analytical Testing

Why Testing Matters

Research-grade B7-33 should undergo testing to verify:

• Identity

• Purity

• Stability

• Potency

• Batch consistency

Common Testing Methods

High-Performance Liquid Chromatography (HPLC)

Used to evaluate peptide purity and identify impurities.

Mass Spectrometry (MS)

Used to confirm molecular identity and sequence verification.

Identity Testing

Confirms peptide authenticity and composition.

Stability Testing

Measures peptide integrity under storage conditions.

Batch Consistency Testing

Ensures reproducibility across manufacturing lots.

Understanding B7-33 Pricing

Several factors influence supplier pricing.

Product Purity

Higher purity products often command premium pricing.

Specialized Manufacturing

B7-33 is a specialized research peptide requiring advanced synthesis and quality-control procedures.

Analytical Verification

Comprehensive testing programs improve transparency but increase production costs.

Limited Market Availability

Compared with more common peptides, B7-33 is generally manufactured in lower volumes.

Vendor Reputation

Trusted suppliers often charge premium prices due to established quality-assurance systems.

B7-33 Vendor Evaluation Checklist

Quality Standards

✅ Third-party testing available

✅ Certificate of Analysis provided

✅ Identity verification documented

✅ Purity information disclosed

✅ Batch-specific testing available

Vendor Reliability

✅ Positive customer reviews

✅ Transparent company information

✅ Responsive customer support

✅ Reliable inventory availability

Purchasing Experience

✅ Secure checkout process

✅ Shipment tracking available

✅ Clear refund policy

✅ Reliable fulfillment performance

Red Flags When Comparing Vendors

Testing Concerns

❌ No third-party testing

❌ Missing COAs

❌ Unverified purity claims

❌ Outdated analytical reports

Transparency Issues

❌ Hidden product specifications

❌ Missing batch information

❌ Limited documentation

❌ No company contact information

Service Problems

❌ Frequent stock shortages

❌ Poor communication

❌ Negative customer reviews

❌ Unclear shipping policies

How to Choose the Best B7-33 Vendor

Prioritize Laboratory Transparency

Look for vendors that provide third-party testing and batch-specific Certificates of Analysis.

Compare Overall Value

Balance pricing against purity, testing quality, customer support, and supplier reliability.

Review Product Documentation

Verify identity testing and analytical reports before purchasing.

Evaluate Vendor Reputation

Established peptide suppliers often provide greater consistency and stronger quality-control standards.

Match Products to Research Objectives

Choose suppliers whose product specifications align with your laboratory and research requirements.

Frequently Asked Questions

What is B7-33?

B7-33 is a synthetic relaxin-derived peptide engineered to retain anti-fibrotic signaling while minimizing certain pathways activated by full-length H2-relaxin.

What is B7-33 used for in research?

Researchers investigate B7-33 in studies involving fibrosis, cardiovascular remodeling, pulmonary biology, vascular function, tissue repair, and biomaterials research.

Why compare B7-33 vendors?

Purity levels, testing standards, analytical verification, documentation quality, and pricing can vary significantly among suppliers.

What should researchers evaluate before purchasing?

Researchers should review:

• Certificate of Analysis

• Purity testing

• Third-party verification

• Identity confirmation

• Vendor reputation

• Customer reviews

Why is third-party testing important?

Independent laboratory testing helps verify product identity, purity, and batch consistency.

Is the cheapest vendor always the best choice?

No. Product quality, testing transparency, and supplier reliability are often more important than price alone.

How often should vendor comparisons be updated?

Pricing, inventory availability, testing procedures, and supplier policies can change frequently and should be reviewed regularly.

Final Thoughts

B7-33 is one of the most promising relaxin-derived peptides currently under investigation because of its selective signaling profile and powerful anti-fibrotic properties. Researchers continue exploring its role in cardiac fibrosis, pulmonary remodeling, vascular dysfunction, biomaterials science, wound healing, and regenerative medicine.

When comparing B7-33 vendors, researchers should prioritize purity verification, independent laboratory testing, COA availability, supplier reputation, and overall value rather than focusing solely on cost. A structured vendor-comparison process can help identify suppliers capable of meeting rigorous research-quality standards.