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 Modified GRF (1-29)?

Modified GRF (1-29) is a peptide analogue of growth-hormone-releasing hormone (GHRH). Modified GRF was first developed in the 1980s when it was discovered that the first 29 amino acids of GHRH retained all of the properties of the full 44-amino-acid protein. The original protein, called GRF (1-29), is the smallest fragment of GHRH that retains all of the properties of GHRH. Another truncated synthetic form of GHRH called Sermorelin or GRF 1-29 has 29 amino acids; Modified GRF (1-29) is further modified in that it has four substituted aminos in its chain that serve the purposes of preventing degradation and oxidation in manufacture and transport as well as in vivo, while also increasing binding affinity to the GHRH receptors.

Though GRF had full effect, the duration of action was limited due to a very short half-life (less than 10 minutes). As a result, researchers modified GRF (1-29) to give it a longer half-life and thus greater therapeutic potential. Modified GRF (1-29) is occasionally referred to as mod GRF or tetrasubstituted GRF (1-29). The latter name makes it clear that mod GRF differs from GRF (1-29) as a result of four amino acids being changed. Modified GRF (1-29) is identical to CJC-1295 without DAC.

Modified GRF (1-29) Structure

Sequence: Tyr-D-Ala-Asp-Ala-Ile-Phe-Thr-Gln-Ser-Tyr-Arg-Lys-Val-Leu-Ala-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Leu-Ser-Arg

Sermorelin Sequence: Tyr-Ala-Asp-Ala-Ile-Phe-Thr-Asn-Ser-Tyr-Arg-Lys-Val-Leu-Gly-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Met-Ser-Arg

Molecular Formula: C152H252N44O42 Molecular Weight: 3367.954 g/mol PubChem CID: 56841945 CAS Number: 863288-34-0

Modified GRF (1-29) Research

Modified GRF has the same effects as GHRH. These effects include muscle growth (hypertrophy), accelerated wound healing, improved bone growth, enhanced fat burning, and accelerated metabolism. Modified GRF also has positive effects on the immune system and blood sugar regulation.

1. Mod GRF and the Intestine

Early research suggested that GH had positive effects on Crohn’s disease, short bowel syndrome, and other inflammatory bowel conditions. Unfortunately, the benefits of GH in this setting are far outweighed by the side effects of long-term exogenous administration. This prompted researchers to look at whether GHRH analogues might have similar effects without the same serious side effects. Research in monkeys indicates that mod GRF interacts with vasoactive intestinal peptide (VIP) receptors and actually improves bowel motility. The peptide appears to interact with VIPC1, which is found on the smooth muscle of the gastrointestinal, reproductive, and urinary systems[1], [2]. Improved bowel motility is of substantial importance in inflammatory bowel diseases associated with constipation. These conditions lead to a great deal of morbidity and are currently difficult to treat due to lack of drug options.

2. Mod GRF and Heart Function

Research in rodent models suggests that modified GRF and other GHRH derivatives may improve the ability of the heart to pump blood following heart attack[3]. This could be of profound use in improving quality of life and reducing death over the long-term in individuals diagnosed with heart failure. The range of disease this finding could be applied to include pulmonary hypertension, heart failure, heart attack, and any number of congenital heart conditions.

3. The Interaction Between Thyroid Hormone and Growth Hormone

Problems with the thyroid gland are often associated with concomitant problems in GH release. To probe this interaction, scientists stimulated individuals suffering from hypothyroidism with modified GRF. They found that individuals given thyroid replacement hormone had stronger reactions to GRF, proving a link between thyroid hormone and GH [4]. This is just one of a number of ways that peptides like modified GRF can help scientists to better understand human physiology.

Modified GRF exhibits moderate side effects, low oral and excellent subcutaneous bioavailability in mice. Per kg dosage in mice does not scale to humans. Modified GRF for sale at Peptide  review is limited to educational and scientific research only, not for human consumption. Only buy Modified GRF if you are a licensed researcher.

Article Author

The above literature was researched, edited and organized by Dr. Logan, M.D. Dr. Logan holds a doctorate degree from Case Western Reserve University School of Medicine and a B.S. in molecular biology.

Modified GRF (1-29), also known as Mod GRF, Tetrasubstituted GRF (1-29), and CJC-1295 without DAC, is a synthetic growth hormone-releasing hormone (GHRH) analogue widely studied in endocrinology, metabolism, growth-factor signaling, regenerative biology, and growth hormone research. Researchers investigate Modified GRF because it retains the biological activity of GHRH while incorporating structural modifications that improve stability and receptor interaction.

As interest in growth hormone secretagogues and GHRH analogues continues to expand, researchers frequently compare Modified GRF suppliers based on purity, analytical testing, pricing, product consistency, and supplier transparency.

This Modified GRF 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 searching for the most affordable Modified GRF supplier, the highest-purity research-grade product, or vendors with extensive laboratory verification, this guide provides a framework for comparing peptide suppliers.

Explore Modified GRF Vendors by Criteria

Most Popular Modified GRF Vendors

Compare suppliers frequently selected by endocrine and growth-hormone researchers.

Highest Reviewed Modified GRF Vendors

Discover peptide companies with strong customer satisfaction and positive marketplace reputations.

Lowest Price Modified GRF Vendors

Identify vendors offering attractive pricing and favorable cost-per-milligram value.

Highest Purity Modified GRF Vendors

Review suppliers providing transparent purity verification and analytical testing.

Best Value Modified GRF Vendors

Compare pricing, product quality, testing documentation, and customer support.

Fastest Shipping Modified GRF Vendors

Evaluate shipping speed, packaging quality, and order-fulfillment reliability.

Newly Listed Modified GRF Vendors

Explore recently added suppliers offering Modified GRF research peptides.

What Is Modified GRF (1-29)?

Overview

Modified GRF (1-29) is a synthetic analogue of Growth Hormone-Releasing Hormone (GHRH).

Researchers investigate Modified GRF because of its relationship with:

• Growth hormone signaling

• Endocrine regulation

• Growth-factor biology

• IGF-1 pathways

• Protein metabolism

• Cellular growth mechanisms

• Regenerative biology

• Metabolic regulation

Modified GRF was designed as an optimized version of the original GRF (1-29) molecule by incorporating amino-acid substitutions that improve stability and reduce degradation.

Molecular Characteristics

Peptide Information

Researchers evaluating Modified GRF products should review product specifications and analytical documentation carefully.

Peptide Name

Modified GRF (1-29)

Alternative Names

• Mod GRF

• Tetrasubstituted GRF (1-29)

• CJC-1295 Without DAC

Amino Acid Sequence

Tyr-D-Ala-Asp-Ala-Ile-Phe-Thr-Gln-Ser-Tyr-Arg-Lys-Val-Leu-Ala-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Leu-Ser-Arg

Molecular Formula

C152H252N44O42

Molecular Weight

3367.95 g/mol

PubChem CID

56841945

CAS Number

863288-34-0

Classification

Growth Hormone-Releasing Hormone (GHRH) Analogue

Research Category

Endocrine & Growth Hormone Research

How Modified GRF Differs From Sermorelin

Researchers frequently compare Modified GRF with Sermorelin because both originate from GHRH research.

Modified GRF

• Four amino-acid substitutions

• Increased stability

• Improved receptor affinity

• Reduced degradation

• Longer functional activity

Sermorelin

• Based on native GRF (1-29)

• Shorter biological half-life

• Fewer structural modifications

• More susceptible to enzymatic breakdown

These distinctions have made Modified GRF a subject of continued research interest.

Why Researchers Compare Modified GRF Vendors

Research reproducibility depends heavily on peptide quality and manufacturing consistency.

Differences among suppliers may include:

• Product purity

• Batch consistency

• Manufacturing quality

• Stability testing

• Product documentation

• Storage procedures

• Shipping standards

• Quality-control systems

Careful supplier evaluation helps improve research reliability and experimental reproducibility.

How We Compare Modified GRF Vendors

Third-Party Laboratory Testing

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

Researchers should prioritize suppliers offering:

• Third-party testing

• Identity verification

• Purity analysis

• Batch-specific reports

Certificate of Analysis (COA)

A quality COA should contain:

• Batch number

• Testing date

• Purity percentage

• Identity confirmation

• Analytical methodology

Product Purity

Purity remains one of the most important considerations when evaluating research peptides.

Higher-purity products generally offer greater experimental consistency.

Cost Per Milligram

Comparing overall vial prices can be misleading.

Cost Per Milligram Formula

Product Price ÷ Total Milligrams = Cost Per Milligram

This metric helps researchers compare suppliers more accurately.

Customer Reviews

Customer feedback often provides insight regarding:

• Product consistency

• Packaging quality

• Shipping reliability

• Customer support

• Purchasing experience

Vendor Reputation

Established suppliers often demonstrate:

• Transparent quality-control standards

• Strong testing programs

• Reliable inventory management

• Positive marketplace reputation

Current Research & Evidence

Growth Hormone Research

The primary focus of Modified GRF research involves growth hormone signaling pathways.

Researchers continue investigating:

• Growth hormone release

• Endocrine regulation

• Hormonal communication

• Growth-factor signaling

• Pituitary function

This remains the central area of Modified GRF investigation.

Growth-Factor Biology Research

Studies continue examining pathways involving:

• IGF-1 signaling

• Cellular growth mechanisms

• Protein synthesis regulation

• Metabolic communication networks

Researchers remain interested in these endocrine interactions.

Key Findings on Modified GRF Research

Gastrointestinal Research

Experimental studies have investigated Modified GRF because of its apparent interaction with gastrointestinal signaling mechanisms.

Researchers continue studying pathways involving:

• Intestinal motility

• Gastrointestinal smooth muscle activity

• Vasoactive intestinal peptide (VIP) signaling

• Digestive-system regulation

This remains an emerging area of research.

Cardiovascular Research

Scientists continue examining Modified GRF in studies involving:

• Cardiac signaling pathways

• Heart function models

• Myocardial biology

• Cardiovascular adaptation mechanisms

Research remains ongoing in this field.

Growth Hormone & Thyroid Research

Researchers have investigated relationships between:

• Growth hormone signaling

• Thyroid-hormone biology

• Endocrine communication

• Hormonal regulation networks

These studies continue advancing understanding of endocrine interactions.

Metabolic Research

Investigations continue examining pathways involving:

• Energy utilization

• Protein metabolism

• Nutrient signaling

• Metabolic adaptation

This remains an active area of study.

Bone Biology Research

Researchers continue evaluating growth-hormone-related pathways involving:

• Skeletal development

• Bone remodeling

• Growth-factor activity

• Musculoskeletal biology

Additional studies remain ongoing.

Recovery & Regenerative Research

Experimental research has investigated pathways involving:

• Tissue-repair signaling

• Cellular adaptation

• Growth-factor communication

• Recovery mechanisms

These areas continue to attract scientific interest.

Why Researchers Study Modified GRF

Modified GRF remains popular because it spans multiple areas of endocrine and metabolic research.

Common areas of investigation include:

• Growth hormone biology

• Endocrinology

• Growth-factor signaling

• Metabolism

• Gastrointestinal science

• Cardiovascular biology

• Bone physiology

• Regenerative research

This broad research profile contributes to its continued popularity.

Research Limitations

Most findings involving Modified GRF originate from:

• Cell-culture studies

• Animal models

• Laboratory investigations

• Early-stage translational research

Additional studies remain necessary to fully characterize biological mechanisms and long-term effects.

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

Product Quality & Analytical Testing

Why Testing Matters

Research-grade Modified GRF products should undergo testing to verify:

• Identity

• Purity

• Stability

• Potency

• Batch consistency

Common Testing Methods

High-Performance Liquid Chromatography (HPLC)

Used to assess purity and identify impurities.

Mass Spectrometry (MS)

Used to verify molecular identity and composition.

Identity Verification Testing

Confirms peptide authenticity.

Stability Testing

Measures peptide integrity during storage.

Batch Consistency Testing

Evaluates manufacturing reproducibility.

Understanding Modified GRF Pricing

Several factors influence pricing among peptide suppliers.

Product Purity

Higher-purity products often command premium pricing.

Analytical Verification

Comprehensive testing improves transparency while increasing production costs.

Manufacturing Standards

Strict quality-control standards can significantly affect pricing.

Specialized Research Demand

Modified GRF remains a highly studied growth-hormone-releasing peptide, contributing to ongoing demand.

Vendor Reputation

Trusted suppliers frequently charge more due to established quality-assurance systems.

Modified GRF Vendor Evaluation Checklist

Quality Verification

✅ 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 policies

✅ Reliable order fulfillment

Red Flags When Comparing Vendors

Testing Concerns

❌ No third-party testing

❌ Missing COAs

❌ Unverified purity claims

❌ Outdated laboratory 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

Frequently Asked Questions

What is Modified GRF (1-29)?

Modified GRF (1-29) is a synthetic Growth Hormone-Releasing Hormone (GHRH) analogue engineered to improve stability and receptor interaction compared with earlier GHRH fragments.

What is Modified GRF used for in research?

Researchers investigate Modified GRF in studies involving growth hormone signaling, endocrine regulation, IGF-1 pathways, metabolic biology, cardiovascular research, gastrointestinal function, and growth-factor signaling.

Why compare Modified GRF vendors?

Purity, testing standards, documentation quality, pricing, and supplier reliability can vary significantly among vendors.

What should researchers review before purchasing?

Researchers should evaluate:

• Certificate of Analysis (COA)

• 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 while improving transparency.

Is the cheapest supplier always the best option?

No. Product quality, documentation, purity verification, and supplier reliability are often more important than price alone.

How often should vendor comparisons be updated?

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

Final Thoughts

Modified GRF (1-29) remains one of the most widely researched Growth Hormone-Releasing Hormone analogues because of its relationship with growth hormone signaling, endocrine regulation, metabolic biology, growth-factor pathways, gastrointestinal research, cardiovascular studies, and regenerative science. Its enhanced stability compared with earlier GHRH fragments continues to make it a valuable tool in laboratory investigation.

When comparing Modified GRF vendors, researchers should prioritize purity verification, third-party laboratory testing, Certificate of Analysis availability, supplier reputation, and overall value rather than focusing solely on price. A structured vendor-comparison process can help identify suppliers capable of meeting rigorous research-quality standards.