S-23 is a non-steroidal selective androgen receptor modulator (SARM) with one of the highest measured binding affinities to the androgen receptor among known SARM compounds, originally investigated in the context of male contraceptive development.
Binding Profile and Hormonal Interactions
S-23 was developed by GTx Inc. and exhibits a binding affinity to the androgen receptor in preclinical studies comparable to that of dihydrotestosterone (DHT). As a full agonist at muscle and bone receptors and a partial antagonist in prostatic tissue, S-23 displays a differentiated tissue profile. Notably, animal studies demonstrated pronounced suppression of endogenous gonadotropins LH and FSH, leading to inhibition of spermatogenesis — a finding that motivated its original investigation as a potential male contraceptive. This effect was reversible in animal models following discontinuation of the compound. The degree of hypothalamic-pituitary axis suppression observed with S-23 is more pronounced than with many other SARMs, making it of particular interest in a research context.
Chemical Characteristics and Metabolism
S-23 belongs to the class of arylpropionamide-based SARMs and features cyano and trifluoromethyl groups that contribute to its high receptor affinity. Chlorine substitution on the aromatic ring increases the metabolic stability of the compound. A comparatively long half-life has been observed in animal studies. Human pharmacokinetic data are not available; clinical trials in humans have not yet been completed. The compound is intended exclusively for research purposes and is not approved as a medicinal product.
Product Range & Selection
The following formulations are available for scientific applications:
S-23 | 10 mg/Tab | 30 Tablets | Vital Research – Oral dosage form containing 10 mg S-23 per tablet; suitable for preclinical research applications requiring a defined oral dose.
S-23 | 10 mg/vial | 1 Vial | Master Pharma – Injectable formulation containing 10 mg of active compound per vial; enables parenteral administration scenarios in controlled experimental settings.
Lab Tested