S4, commonly known as Andarine, is an experimental non-steroidal selective androgen receptor modulator (SARM) investigated for its interaction with androgen receptors and its effects on androgen-responsive biological pathways. Research involving S4 has examined androgen receptor binding, anabolic signaling, skeletal muscle biology, bone-related pathways, and tissue-selective receptor activity. Andarine is identified in chemical databases as a non-steroidal SARM and has also been studied as a research compound in preclinical models.

S4 is a single-molecule research compound rather than a peptide or multi-component formulation. When evaluating an S4 research material, researchers should review documentation covering compound identity, purity, lot information, analytical testing, storage requirements, and the applicable certificate of analysis (COA). S4 should be regarded strictly as a research material and is not intended for human consumption, diagnosis, prevention, or treatment of any disease or medical condition.

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What is S4 (Andarine)?

S4, or Andarine, is a synthetic, non-steroidal compound classified as a selective androgen receptor modulator. It was developed as an investigational compound for studying androgen receptor activity and tissue-selective pharmacology. PubChem identifies Andarine as a non-steroidal SARM and lists GTX-007, S-4, and Andarine among its identifiers.

Research has examined the compound's ability to interact with androgen receptors and produce receptor-mediated biological responses. Experimental studies have particularly focused on the relationship between androgen receptor activation and anabolic activity in tissues such as skeletal muscle and bone.

Overview

S4 represents an experimental model for investigating selective androgen receptor pharmacology. Unlike steroidal androgens, it is structurally distinct from testosterone and belongs to the non-steroidal SARM class.

Research interest in S4 includes:

• Androgen Receptor Biology: Studying ligand binding and receptor-mediated signaling.

• Skeletal Muscle Research: Investigating androgen-responsive pathways associated with muscle tissue.

• Bone Biology: Examining androgen receptor activity in bone-related experimental models.

• Tissue Selectivity: Studying differences in androgen receptor responses between tissues.

• Pharmacology: Investigating the relationship between receptor binding, biological activity, metabolism, and pharmacokinetics.

• Analytical Research: Characterizing S4 and its metabolites using laboratory analytical techniques.

These areas describe experimental research applications and should not be interpreted as established therapeutic uses.

Molecular Characteristics

According to PubChem, Andarine has the following molecular characteristics:

• Chemical Name: (2S)-3-(4-acetamidophenoxy)-2-hydroxy-2-methyl-N-[4-nitro-3-(trifluoromethyl)phenyl]propanamide

• Common Names: S4, Andarine, GTX-007

• CAS Number: 401900-40-1

• Molecular Formula: C₁₉H₁₈F₃N₃O₆

• Molecular Weight: 441.4 g/mol

• Compound Type: Non-steroidal selective androgen receptor modulator

• Research Classification: Experimental androgen receptor ligand

Researchers should use the product-specific COA and analytical documentation to verify identity, purity, concentration, and batch characteristics rather than relying solely on catalog descriptions.

Research Applications

S4 may be investigated in laboratory and preclinical research involving:

• Androgen Receptor Signaling: Examining ligand-mediated activation and downstream receptor pathways.

• Muscle Biology: Studying androgen-responsive signaling in skeletal muscle models.

• Bone Research: Investigating androgen receptor activity in bone and musculoskeletal systems.

• Selective Pharmacology: Evaluating tissue-dependent differences in receptor activation.

• Receptor-Ligand Studies: Characterizing interactions between S4 and androgen receptors.

• Metabolism Research: Studying the formation and identification of S4 metabolites.

• Analytical Chemistry: Developing methods for compound identification and metabolite detection.

• Preclinical Pharmacology: Evaluating pharmacokinetic and pharmacodynamic characteristics in appropriate experimental models.

The presence of research activity in these areas does not establish S4 as an approved treatment or demonstrate that experimental findings translate directly to humans.

Mechanism of Research Interest

The primary research interest in S4 comes from its interaction with the androgen receptor (AR). Andarine has been characterized as a non-steroidal androgen receptor ligand with agonist activity. Research has investigated its ability to bind the receptor and influence androgen-responsive biological pathways.

Early pharmacological research identified S4 as a compound with high androgen receptor binding affinity and investigated its anabolic specificity in animal models. Studies examined differences between androgen-responsive tissues, helping establish S4 as a model compound for investigating selective androgen receptor modulation.

Because receptor activity can vary according to experimental conditions, species, tissue type, concentration, and study design, results from preclinical models should not automatically be interpreted as evidence of equivalent activity in humans.

Preclinical Research

Preclinical research on S4 has included studies of androgen receptor binding, tissue-selective activity, pharmacokinetics, metabolism, and androgen-responsive biological effects. Experimental animal studies helped characterize S4 as a non-steroidal androgen receptor modulator with activity in skeletal muscle and comparatively different activity in other androgen-sensitive tissues.

Analytical research has also investigated S4 metabolites using liquid chromatography and high-resolution mass spectrometry. Such work is relevant to understanding compound metabolism and to developing methods for detecting S4 and its metabolites in biological samples.

The available evidence is primarily preclinical and experimental. Researchers should therefore distinguish findings generated in cell or animal models from evidence obtained through controlled human clinical research.

Product Quality & Analytical Testing

Research-grade S4 should be evaluated using appropriate analytical methods to confirm compound identity, purity, and batch consistency. Depending on the intended laboratory application, quality assessment may include:

• HPLC: Assessment of chemical purity and related impurities.

• Mass Spectrometry: Confirmation of molecular mass and compound identity.

• Chromatographic Analysis: Detection of related compounds or degradation products.

• NMR Analysis: Structural characterization where appropriate.

• Metabolite Analysis: Identification and characterization of S4 metabolites in suitable research samples.

• Batch Testing: Comparison of analytical characteristics between production lots.

• Stability Testing: Evaluation of compound integrity under defined storage conditions.

Researchers should review the certificate of analysis (COA), batch number, stated purity, analytical methodology, storage requirements, and manufacturer documentation before incorporating S4 into laboratory research.

Research Use Only: S4 (Andarine) is an experimental research compound and is not an approved medication, dietary supplement, or established medical treatment. It should not be represented as a treatment for muscle loss, fat loss, osteoporosis, hormonal conditions, or any other medical condition. Research materials should be handled according to applicable laboratory procedures, institutional requirements, manufacturer specifications, and relevant regulations. Independent verification of compound identity, purity, and analytical documentation is recommended before research use.

S4 (Andarine) is an experimental Selective Androgen Receptor Modulator (SARM) extensively investigated in androgen receptor signaling, skeletal muscle biology, bone research, tissue-selective pharmacology, receptor-ligand interactions, and preclinical pharmacology.

As a non-steroidal androgen receptor ligand, S4 provides researchers with a valuable model for studying androgen receptor activation, anabolic signaling pathways, tissue-selective receptor responses, and the biological effects of androgen-responsive signaling systems. Its unique pharmacological profile has made it one of the most recognized compounds in selective androgen receptor research.

This S4 Vendor Price Comparison Guide helps researchers evaluate suppliers using objective criteria including:

• Product Pricing

• Cost Per Milligram

• Active Ingredient Verification

• Product Purity

• Third-Party Testing

• Certificate of Analysis (COA)

• Batch Consistency

• Vendor Reputation

• Customer Reviews

• Shipping Performance

• Product Availability

• Overall Value

Whether you're searching for the lowest-priced S4 supplier, the highest-purity Andarine product, or vendors offering comprehensive analytical verification, this guide provides a structured framework for supplier evaluation.

Explore S4 Vendors by Criteria

Most Popular S4 Vendors

Compare suppliers frequently selected by androgen receptor and SARM researchers.

Highest Reviewed Vendors

Discover vendors with strong customer satisfaction and established reputations.

Lowest Price Vendors

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

Highest Purity Vendors

Review suppliers providing transparent analytical testing and purity verification.

Best Value Vendors

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

Fastest Shipping Vendors

Evaluate fulfillment reliability, packaging quality, and delivery performance.

Newly Listed Vendors

Explore recently added suppliers offering S4 research materials.

What Is S4 (Andarine)?

Overview

S4 contains:

• Andarine

• GTX-007

• S4

• Non-Steroidal Selective Androgen Receptor Modulator (SARM)

• Experimental Androgen Receptor Ligand

Researchers investigate S4 because of its relationship with:

• Androgen receptor activation

• Tissue-selective pharmacology

• Skeletal muscle signaling

• Bone biology

• Receptor-ligand interactions

• Anabolic signaling pathways

• Preclinical pharmacology

• Metabolism research

Its selective interaction with androgen receptors makes it an important model compound for studying androgen-responsive biological systems.

Molecular Characteristics

Compound Information

Researchers evaluating S4 products should carefully review supplier specifications and analytical documentation.

Active Ingredient

Andarine (S4)

Alternate Names

• GTX-007

• S-4

• Andarine

Chemical Classification

Non-Steroidal Selective Androgen Receptor Modulator (SARM)

CAS Number

401900-40-1

Molecular Formula

C₁₉H₁₈F₃N₃O₆

Molecular Weight

441.4 g/mol

Research Category

Androgen Receptor & SARM Research

Compound Type

Experimental Androgen Receptor Ligand

What Makes S4 Different?

The defining feature of S4 is its interaction with the androgen receptor (AR) while maintaining a non-steroidal chemical structure.

Androgen Receptor Research Utility

Researchers investigate:

• Receptor binding

• Ligand activation

• Signal-transduction pathways

• Cellular responsiveness

• Tissue-selective activity

Tissue Selectivity Research

Scientists frequently study:

• Tissue-dependent receptor responses

• Differential signaling pathways

• Cellular adaptation

• Receptor pharmacology

• Biological specificity

Non-Steroidal Pharmacology

Researchers examine:

• Structure-activity relationships

• Receptor selectivity

• Pharmacodynamic responses

• Molecular interactions

• Cellular regulation

Why Researchers Study S4

Andarine remains widely investigated because of its relationship with:

• Androgen receptor biology

• Skeletal muscle signaling

• Bone physiology

• Receptor pharmacology

• Tissue-selective responses

• Cellular signaling pathways

• Metabolism research

• Experimental endocrinology

These continue to be major areas of preclinical and molecular research.

Mechanism of Research Interest

Androgen Receptor Signaling

The primary scientific interest surrounding S4 involves interaction with androgen receptors.

Researchers investigate pathways involving:

• Receptor activation

• Ligand binding

• Signal transduction

• Gene regulation

• Cellular adaptation

This remains the central focus of Andarine research.

Receptor-Ligand Interaction Research

Researchers frequently examine:

• Binding affinity

• Receptor responsiveness

• Cellular signaling

• Molecular communication

• Biological regulation

S4 & Androgen Receptor Research

Receptor Biology Research

Researchers investigate pathways involving:

• Androgen receptor activation

• Cellular signaling

• Receptor modulation

• Molecular communication

• Signal-transduction pathways

This remains one of the most common applications of S4 research.

Selective Receptor Activity Research

Scientists continue studying:

• Selective receptor responses

• Tissue-dependent signaling

• Pharmacological regulation

• Cellular adaptation

• Molecular responsiveness

Gene-Regulation Research

Studies frequently investigate:

• Androgen-responsive pathways

• Transcriptional regulation

• Cellular communication

• Physiological adaptation

• Signaling networks

S4 & Skeletal Muscle Research

Muscle Biology Research

Researchers investigate pathways involving:

• Androgen-responsive signaling

• Skeletal muscle physiology

• Cellular regulation

• Tissue adaptation

• Molecular communication

Anabolic Signaling Research

Scientists frequently examine:

• Growth-related pathways

• Signal-transduction mechanisms

• Cellular responses

• Gene-expression regulation

• Physiological adaptation

Muscle Cell Research

Studies continue evaluating:

• Cellular differentiation

• Tissue responsiveness

• Regulatory signaling

• Biological adaptation

• Experimental muscle models

S4 & Bone Biology Research

Bone Signaling Research

Researchers investigate pathways involving:

• Androgen-responsive bone pathways

• Cellular communication

• Skeletal signaling

• Tissue maintenance

• Biological regulation

Musculoskeletal Research

Scientists continue studying:

• Bone physiology

• Musculoskeletal adaptation

• Cellular signaling

• Structural regulation

• Molecular responsiveness

Bone Cell Research

Studies frequently examine:

• Signaling pathways

• Cellular regulation

• Skeletal development models

• Tissue adaptation

• Experimental physiology

S4 & Selective Pharmacology Research

Tissue Selectivity Research

Researchers investigate:

• Differential tissue responses

• Receptor-mediated signaling

• Pharmacological variability

• Biological adaptation

• Molecular interactions

Structure-Activity Relationship Research

Scientists continue examining:

• Compound-receptor interactions

• Molecular pharmacology

• Ligand optimization

• Cellular responsiveness

• Biological specificity

S4 & Metabolism Research

Metabolite Identification Research

Researchers investigate:

• Compound biotransformation

• Metabolite formation

• Metabolic pathways

• Biochemical regulation

• Molecular characterization

Analytical Metabolism Research

Scientists frequently study:

• Metabolite detection

• Analytical characterization

• Compound identification

• Research methodology

• Biological processing

S4 & Preclinical Pharmacology Research

Pharmacokinetic Research

Researchers investigate:

• Absorption characteristics

• Distribution pathways

• Metabolic transformation

• Elimination mechanisms

• Exposure-response relationships

Pharmacodynamic Research

Scientists continue studying:

• Receptor occupancy

• Biological responsiveness

• Cellular adaptation

• Signal regulation

• Molecular communication

Experimental Pharmacology

Research frequently examines:

• Receptor-mediated responses

• Pharmacological activity

• Biological signaling

• Experimental models

• Mechanistic pathways

Why Researchers Compare S4 Vendors

Research reproducibility depends heavily on material quality and manufacturing consistency.

Differences among suppliers may include:

• Andarine purity

• Active ingredient concentration

• Analytical verification

• Stability testing

• Identity confirmation

• Manufacturing standards

• Batch consistency

• Documentation quality

Careful supplier evaluation helps improve consistency across laboratory studies.

How We Compare S4 Vendors

Third-Party Laboratory Testing

Researchers should prioritize suppliers offering:

✅ Third-party testing

✅ Identity verification

✅ Purity confirmation

✅ Batch-specific reports

✅ Analytical documentation

Certificate of Analysis (COA)

A quality COA should include:

• Batch number

• Testing date

• Identity verification

• Purity confirmation

• Analytical methodology

Active Ingredient Verification

Researchers should verify:

• Andarine identity

• Purity percentage

• Product consistency

• Stability profile

• Analytical validation

Cost Per Milligram

Comparing package prices alone may not accurately reflect value.

Cost Per Milligram Formula

Product Price ÷ Total Milligrams = Cost Per Milligram

These standardized measurements help researchers compare products across vendors.

Customer Reviews

Customer experiences often provide insight regarding:

• Product consistency

• Packaging quality

• Shipping reliability

• Customer support

• Overall purchasing experience

Vendor Reputation

Established suppliers often demonstrate:

• Transparent testing procedures

• Reliable quality-control systems

• Positive customer feedback

• Consistent product availability

Quality & Analytical Testing

Why Testing Matters

Research-grade S4 should undergo testing to verify:

• Identity

• Purity

• Stability

• Batch consistency

• Analytical integrity

Common Testing Methods

High-Performance Liquid Chromatography (HPLC)

Used to assess purity and detect related impurities.

Liquid Chromatography-Mass Spectrometry (LC-MS)

Used to confirm molecular identity and composition.

Nuclear Magnetic Resonance (NMR)

Used to verify molecular structure and compound integrity.

Identity Testing

Confirms Andarine authenticity.

Metabolite Analysis

Evaluates compound metabolism and metabolite characterization.

Stability Testing

Monitors degradation and long-term storage performance.

Batch Testing

Measures consistency between production lots.

Storage & Handling

Researchers should follow validated laboratory procedures.

Best practices include:

✅ Store according to supplier recommendations

✅ Protect from excessive heat

✅ Protect from moisture

✅ Protect from direct sunlight

✅ Maintain original packaging

✅ Keep containers sealed when not in use

✅ Inspect materials before laboratory use

✅ Maintain laboratory documentation

Proper storage helps preserve chemical stability and analytical integrity.

Understanding S4 Pricing

Several factors influence supplier pricing.

Product Purity

Higher-purity materials generally command premium pricing.

Manufacturing Standards

Advanced manufacturing and quality-control procedures contribute to production costs.

Analytical Verification

Comprehensive testing programs improve transparency while increasing quality-assurance expenses.

Stability Validation

Additional stability studies may increase overall product value.

Vendor Reputation

Established suppliers frequently command higher pricing because of documented testing standards and rigorous quality-control systems.

S4 Vendor Evaluation Checklist

Quality Verification

✅ Third-party testing available

✅ Certificate of Analysis provided

✅ Identity verification documented

✅ Purity testing available

✅ Stability testing available

✅ Batch-specific reports available

✅ Analytical methodology disclosed

Vendor Reliability

✅ Positive customer reviews

✅ Transparent company information

✅ Responsive customer support

✅ Reliable inventory availability

Purchasing Experience

✅ Secure checkout process

✅ Shipment tracking available

✅ Clear return policies

✅ Reliable order fulfillment

Frequently Asked Questions

What is S4 (Andarine)?

S4, also known as Andarine or GTX-007, is an experimental non-steroidal Selective Androgen Receptor Modulator (SARM) studied in androgen receptor and tissue-selective pharmacology research.

What is S4 used for in research?

Researchers investigate S4 in studies involving androgen receptor signaling, skeletal muscle biology, bone physiology, receptor-ligand interactions, selective pharmacology, metabolism research, and experimental pharmacology.

Why is S4 important in androgen receptor research?

Its ability to bind androgen receptors and produce receptor-mediated biological responses provides a useful model for studying androgen-responsive signaling pathways and tissue-selective receptor activity.

What should researchers review before purchasing?

Researchers should evaluate:

• Certificate of Analysis (COA)

• HPLC verification

• LC-MS confirmation

• NMR analysis

• Purity testing

• Stability testing

• Vendor reputation

Why is analytical testing important?

Independent testing helps verify identity, purity, stability, batch consistency, and analytical integrity while improving research reproducibility.

Is S4 a peptide?

No. S4 (Andarine) is a non-steroidal Selective Androgen Receptor Modulator (SARM) and a single-molecule research compound rather than a peptide. However, it is frequently listed alongside peptides and other research compounds by specialized suppliers.

Final Thoughts

S4 (Andarine) remains one of the most widely recognized compounds in androgen receptor research, skeletal muscle biology, bone-signaling investigations, receptor pharmacology, tissue-selective signaling, and preclinical pharmacology. Its interaction with androgen receptors provides researchers with a valuable model for exploring androgen-responsive biological pathways and selective receptor modulation.

When comparing S4 vendors, researchers should prioritize purity verification, third-party analytical testing, Certificate of Analysis availability, HPLC validation, LC-MS confirmation, NMR analysis, stability testing, batch consistency, supplier reputation, and overall value rather than focusing exclusively on price. A structured vendor-comparison process can help identify suppliers capable of maintaining rigorous research-quality standards.