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3D molecular model of S-4 (Andarine)

Calculated reference model · not an experimental or batch-certified structure. All 31 atoms shown.

Model data & sources
  • Heavy atoms only; hydrogens are omitted from the reference display.
  • Source-defined stereochemistry is checked against the calculated coordinates; no energy-minimum, crystal or solution-structure claim is made.
  • Reference molecular species only; batch identity, purity, counterions and excipients are not certified.
Formula
C19H18F3N3O6
Method
RDKit ETKDGv3 / MMFF94s calculated reference conformer

S-4 (Andarine)

By Kimera ChemsSelective Modulators

S-4 (Andarine) Research Standard

S-4, also indexed as andarine (CAS 401900-40-1), is a nonsteroidal arylpropionamide selective androgen receptor modulator, supplied as a reference standard for androgen receptor pharmacology and analytical method development. It is one of the better-characterised compounds in the class on pharmacokinetics, which is what makes it a practical internal comparator.[1]

Mechanism of Action & Research Context

The molecular target is the androgen receptor (AR, NR3C4), a ligand-activated nuclear hormone receptor that functions as a transcription factor.

  • Characterised rodent pharmacokinetics. Across intravenous and oral dosing in rats, clearance ranged 1.0–2.1 mL/min/kg and varied with dose, volume of distribution was approximately 0.448 L/kg across all groups, and half-life fell between 2.6 and 5.3 h. Oral bioavailability was dose-dependent, complete at the lower doses.[1]

  • Defined metabolic routes. In liver S9 incubations the main routes for arylpropionamide SARMs are monohydroxylation, nitro-reduction, dephenylation and demethylation; in vivo these combine with glucuronidation, sulfation and carboxylation. The intact parent remains the principal analyte, which is why methods target it.[2]

  • Purity is a real-world problem for this compound. Material sold outside controlled supply has been analysed and found to carry roughly 10% of a single impurity from poor purification. That is the practical argument for working from a lot with its own COA rather than an unverified source.[3]

  • Distinct genomic and non-genomic routes. Nonsteroidal SARMs and endogenous androgens engage AR through different signalling arms and assemble different AR/cofactor complexes at androgen-responsive enhancers, so the two ligand types are not interchangeable in mechanistic work.[5]

  • Coregulator recruitment and dimerisation. A SARM can drive AR transcriptional activity while producing markedly less AR homodimerisation than DHT and recruiting only a restricted subset of cofactors, with p160 coactivators SRC1, TIF2 and NCoA3 notably absent in yeast two-hybrid assays. Differential coregulator recruitment is the leading mechanistic account of tissue selectivity.[6]

Research Applications

Primary fields of in vitro and preclinical laboratory investigation include:

  • Pharmacokinetic modelling using published clearance, volume and half-life values as a benchmark.[1]

  • Metabolite identification in S9 and microsomal incubations.[2]

  • Purity and impurity profiling by LC-HRMS against reference material.[3]

  • Analytical and forensic method development. Reference material for chromatography-mass spectrometry identification, retention-time matching and metabolite characterisation.[4]

Analytical Documentation

Purity and identity vary by manufacturing lot. Kimera Chems does not publish a single fixed purity figure for this item; refer to the batch-specific Certificate of Analysis (COA) issued for the lot received, which reflects third-party analytical testing for that lot.

References

  1. Kearbey JD, Wu D, Gao W, Miller DD, Dalton JT. Pharmacokinetics of S-3-(4-acetylamino-phenoxy)-2-hydroxy-2-methyl-N-(4-nitro-3-trifluoromethyl-phenyl)-propionamide in rats, a non-steroidal selective androgen receptor modulator. Xenobiotica. 2004;34(3):273–280. doi:10.1080/0049825041008962
  2. de Rijke E, Essers ML, Rijk JCW, et al. Selective androgen receptor modulators: in vitro and in vivo metabolism and analysis. Food Addit Contam Part A. 2013;30(9):1517–1526. doi:10.1080/19440049.2013.810346
  3. Thevis M, Geyer H, Kamber M, Schänzer W. Detection of the arylpropionamide-derived selective androgen receptor modulator (SARM) S-4 (andarine) in a black-market product. Drug Test Anal. 2009;1(8):387–392. doi:10.1002/dta.91
  4. Stacchini C, Botrè F, Comunità F, et al. Simultaneous detection of different chemical classes of selective androgen receptor modulators in urine by liquid chromatography-mass spectrometry-based techniques. J Pharm Biomed Anal. 2021;195:113849. doi:10.1016/j.jpba.2020.113849
  5. Narayanan R, Coss CC, Yepuru M, et al. Steroidal androgens and nonsteroidal, tissue-selective androgen receptor modulator, S-22, regulate androgen receptor function through distinct genomic and nongenomic signaling pathways. Mol Endocrinol. 2008;22(11):2448–2465. doi:10.1210/me.2008-0160
  6. Furuya K, Yamamoto N, Ohyabu Y, et al. Mechanism of the tissue-specific action of the selective androgen receptor modulator S-101479. Biol Pharm Bull. 2013;36(3):442–451. doi:10.1248/bpb.b12-00885

Storage & Handling

Store at controlled room temperature. Keep tightly closed. Liquid formats: do not refrigerate or freeze. Cold storage may cause the solution to cloud or precipitate. If this occurs, return to room temperature and mix until clear.

Storage guidance is a house recommendation. Analytical documentation is per-lot release testing.

Related Research Compounds

Research Use Only Disclaimer: This product is labeled and sold "For Research Use Only - NOT FOR HUMAN CONSUMPTION." It is not a drug, dietary supplement, food, cosmetic, or medical device, and it is not approved by the FDA or any other regulator for human or veterinary use. It is supplied to approved account holders as a research chemical for laboratory use and must be handled in accordance with applicable law.

Kimera Chems

Compounds That Survive Scrutiny

Research use only. Not for human or veterinary use.