S23 is a non steroidal selective androgen receptor modulator (SARM) with one of the highest documented androgen receptor binding affinities among research SARM compounds, a structural characteristic that has positioned it as a frequently referenced compound in studies examining high potency selective androgen receptor activation. F40 Biotech’s formulation delivers 10mg per tablet in a 50 count format, consistent with the concentration most commonly referenced in S23 preclinical research literature.
S23’s research profile is distinguished by its documented dual mechanism affecting both bone and skeletal muscle tissue alongside a notably pronounced HPG axis suppressive effect at the receptor level, a characteristic that differentiates it from LGD-4033 within CSD’s SARM range despite both compounds sharing the broad tissue selective androgen receptor activation principle common to the SARM class. S23 has additionally been studied as a potential male contraceptive research compound, owing to its androgen receptor binding characteristics affecting spermatogenesis related signaling. A research application that is unique among CSD’s SARM listings and reflects the compound’s particularly strong androgen receptor engagement profile compared to other selective modulators.
Like LGD-4033, S23 binds the androgen receptor through a non steroidal mechanism that avoids 5-alpha reductase and aromatase enzyme interaction, eliminating the androgenic and estrogenic conversion pathways associated with traditional anabolic steroids while still activating downstream anabolic signaling in muscle and bone tissue. The comparative research distinction between S23 and LGD-4033 centers on receptor binding affinity and the resulting differences in HPG axis suppression magnitude and tissue selectivity profile. A frequently studied comparison within SARM structure activity relationship research examining how subtle structural variations between non steroidal SARM compounds produce measurably different suppression and selectivity characteristics.
F40 Biotech formulations are stocked by Canada Steroid Depot following the same rigorous third party lab verification process applied to every product in our range. Each batch is tested for concentration accuracy and purity before being made available, with COA documentation available on request. CSD’s sourcing standards apply uniformly across all manufacturers we carry, and F40 Biotech’s S23 meets those standards consistently. All orders ship discreetly across Canada in plain, unmarked packaging with no identifying information on the exterior.
Store in a cool, dry place away from direct light and heat. Intended for research purposes only.
Commonly researched alongside LGD-4033 in comparative SARM receptor binding affinity and tissue selectivity studies. Browse CSD’s full SARM range for complete sourcing.









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