Description
S-40503 Overview
S-40503 is an investigational small-molecule compound in the selective androgen receptor modulator (SARM) class. It was developed and investigated in preclinical research, including research examining androgen-receptor activity and bone-related effects.
For laboratory researchers, S-40503 can be used as a research tool for studying androgen receptor pharmacology, receptor selectivity, molecular signaling, and bone-related biological pathways.
S-40503 should be presented as a research compound, not as a peptide, dietary supplement, or established human therapeutic.
What Is S-40503?
S-40503 is a synthetic, orally active small-molecule androgen receptor modulator investigated primarily in preclinical research.
Research has examined its activity in relation to androgen receptors and bone biology. Published preclinical work reported effects on bone mineral density and biomechanical strength in animal models. These findings are preclinical and should not be interpreted as evidence of safety or efficacy in humans.
Potential research areas include:
- Androgen receptor biology
- SARM pharmacology
- Bone biology
- Receptor-ligand interactions
- Molecular pharmacology
- Structure–activity relationship studies
- Preclinical drug-discovery research
Molecular Formula, Molecular Weight & Chemical Structure
Because S-40503 is a small molecule, a peptide sequence does not apply.
| Property | Specification |
|---|---|
| Product name | S-40503 |
| Compound class | Selective androgen receptor modulator |
| Chemical type | Small molecule |
| Molecular formula | C₁₅H₂₃N₃O₃ |
| Molecular weight | 293.36 g/mol |
| CAS number | 404920-28-1 |
| Peptide sequence | Not applicable |
These molecular specifications are consistent with PubChem and MedChemExpress records.
For professional research documentation, chemical identity should be supported by analytical methods such as HPLC and mass spectrometry.
Purity
A suitable research-grade specification can be presented as:
Purity: ≥98% by HPLC
Only publish this specification when it is supported by the actual batch-specific analytical documentation.
For example, a professional COA may contain:
- HPLC purity
- HPLC chromatogram
- Mass spectrometry
- Expected molecular weight
- Observed molecular weight
- Lot/batch number
- Testing date
- Appearance
- Additional analytical testing where applicable
Some commercial research suppliers report higher assay/purity values for individual S-40503 batches, demonstrating why the specific batch COA should take priority over a generic website specification.
Appearance
S-40503 is a small-molecule research compound, so it should not be described as a “white lyophilized peptide.”
Depending on the formulation and manufacturing process, research material may be supplied as a white to off-white powder.
The exact appearance should always be confirmed against your actual batch documentation.
Visual appearance alone cannot establish chemical identity or purity.
Available Research Quantities
Available quantities should match your actual inventory.
Common research-packaging options can include:
- 10 mg
- 25 mg
- 50 mg
- 100 mg
- 250 mg
For a research-oriented catalog, smaller quantities can be convenient for analytical laboratories, while larger quantities may be suitable for laboratories conducting repeated experiments.
Only advertise quantities you actually stock and can support with appropriate documentation.
Each container should clearly identify:
S-40503 + quantity + lot number + research-use statement
Storage Recommendations
S-40503 should be stored according to the stability information established for the specific batch.
General laboratory considerations include:
- Keep the container tightly closed.
- Protect the compound from excessive moisture.
- Avoid unnecessary heat exposure.
- Protect from direct light.
- Minimize repeated temperature fluctuations.
- Follow the manufacturer’s documented storage conditions.
- Keep the material in its original, properly labeled container.
A professional approach is to direct researchers to the batch-specific COA or technical data sheet for the exact storage requirement rather than publishing an unsupported universal storage temperature. Commercial research documentation likewise advises following the conditions specified in the relevant COA.
Reconstitution / Preparation Information
S-40503 is not a peptide, so conventional peptide reconstitution instructions do not apply.
Laboratory preparation depends on the intended experiment, compound solubility, selected solvent, and required concentration.
Researchers should use an appropriate validated laboratory procedure and document:
- Compound identity
- Lot number
- Solvent
- Concentration
- Preparation date
- Storage conditions
There is no single preparation method appropriate for every S-40503 research application.
This product page does not provide human dosing or administration instructions.
Intended Use — Research Only
S-40503 is intended for laboratory and scientific research purposes only.
Potential research applications include:
- Androgen receptor research
- SARM pharmacology
- Bone biology research
- Receptor-binding studies
- Molecular pharmacology
- Structure–activity relationship studies
- Preclinical drug-discovery research
S-40503 should not be marketed as:
- A bodybuilding supplement
- A muscle-building product
- A testosterone replacement
- A performance-enhancing product
- A medication
- A dietary supplement
- A treatment for osteoporosis or other disease
Although preclinical studies have investigated S-40503 in bone-related models, those findings do not establish a human therapeutic use.
Research Use Only. Not for Human or Veterinary Administration.
Packaging & Shipping Information
Professional packaging should protect the research compound and provide clear identification.
Packaging may include:
- Securely sealed vial or container
- Product identification label
- Net quantity
- Lot/batch number
- Research-use statement
- Protective secondary packaging
- Batch-specific COA
Upon delivery, researchers should inspect the packaging for visible damage and verify:
Product name + quantity + lot number + COA
Shipping conditions should follow the product’s documented stability requirements and applicable transportation regulations.
Frequently Asked Questions About S-40503
What is S-40503?
S-40503 is an investigational small-molecule selective androgen receptor modulator studied primarily in preclinical research.
Is S-40503 a peptide?
No. S-40503 is a small molecule and therefore does not have an amino-acid peptide sequence.
What is the molecular formula?
C₁₅H₂₃N₃O₃.
What is the molecular weight?
293.36 g/mol.
What is the CAS number?
The commonly reported CAS number is 404920-28-1.
Does S-40503 have a peptide sequence?
No. A peptide sequence is not applicable because S-40503 is a small molecule.
What purity should researchers look for?
A research-grade specification may state ≥98% HPLC purity, provided the batch-specific analytical results support the claim.
What does S-40503 look like?
It may be supplied as a white to off-white powder, depending on the formulation and manufacturing process.
Does S-40503 require peptide reconstitution?
No. It is not a peptide. Laboratory preparation depends on the experimental application and compound solubility.
What is S-40503 researched for?
S-40503 has been investigated in relation to androgen receptor pharmacology and bone-related biological research. Preclinical studies have examined effects on bone mineral density and bone strength in animal models.
Should S-40503 have a COA?
Yes. A batch-specific COA is strongly recommended for professional research material and can document HPLC purity, mass spectrometry, molecular identity, and lot information.
How should S-40503 be stored?
Follow the manufacturer’s specifications for the specific batch. Protect the material from excessive moisture, heat, light, and unnecessary temperature fluctuations.
Is S-40503 intended for human use?
A research-grade product should be clearly labeled:
Research Use Only — Not for Human or Veterinary Administration.
Key Takeaway
S-40503 is a small-molecule SARM research compound, not a peptide.
Key specifications
- Product: S-40503
- Compound class: Selective androgen receptor modulator
- Molecular formula: C₁₅H₂₃N₃O₃
- Molecular weight: 293.36 g/mol
- CAS: 404920-28-1
- Peptide sequence: Not applicable
- Purity: ≥98% by HPLC when supported by the relevant COA
- Appearance: Typically white to off-white powder
- Intended use: Laboratory research only
S-40503 has primarily been investigated in preclinical research, including studies of androgen receptor activity and bone-related effects. It should not be presented as an approved human medicine or as a proven treatment.
For a professional product page, emphasize verified chemical identity, documented purity, analytical testing, accurate labeling, appropriate storage information, and batch-specific COA documentation.
Research Use Only. Not for Human or Veterinary Administration.
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Scientific Reference: For additional peer-reviewed information on peptide stability, sterile preparation, and pharmaceutical reconstitution practices, visit
European Medicines Agency (EMA)
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