S-23 – Powder, 1g

S-23 – Powder, 1g

This premium, laboratory-grade research compound delivers ultra-pure raw S-23 powder at ≥98% purity, representing the highest standard for modern scientific investigations into potent selective androgen receptor modulation and anabolic signaling mechanisms in muscle and bone. The lyophilized crystalline powder form provides investigators with a single-compound reference standard ideal for analytical testing, in vitro cell culture modeling of AR-mediated pathways, and in vivo preclinical research applications where precise S-23 administration is critical for studying muscle growth, male contraception, and potent androgenic effects with steroid-like efficacy.

S-23 was discovered by GTX, Inc. (now part of Ionix) and represents one of the most potent SARMs developed, with potency closely resembling that of anabolic steroids while maintaining nonsteroidal structure. In preclinical studies, it demonstrated excellent anabolic-to-androgenic ratio and reversible spermatogenesis suppression.

All shipments to the 50 United States are fulfilled directly from primary U.S. production facilities, ensuring 2-5 business day delivery nationwide. International orders to the United Kingdom and continental Europe are processed through our dedicated United Kingdom shipping hub, which streamlines customs clearance and reduces transit times across all European countries. This dual-hub logistics infrastructure guarantees seamless, compliant delivery while maintaining chemical integrity throughout transit.

• Public third-party lab reports with unique lot-coding ensure absolute transparency for every batch sold

• Formulation contains zero flow agents, excipients, or adulterants—pure S-23 only

• Strategic over-weighing compensates for powder adhesion loss, guaranteeing minimum 1g recoverable material

• PET single-wall jar features UV-resistant construction and tamper-proof seal for transit safety

Technical Specifications & Chemical Profile

Research Applications & Storage Protocols

Potent SARM-Mediated AR Agonism & Muscle/Male Contraception Profiling

S-23 (also known as Mastorin) functions as an investigational selective androgen receptor modulator (SARM) developed by GTX, Inc. as a potential male hormonal contraceptive. The compound is an oral selective androgen receptor modulator (SARM) with a Ki of 1.7 nM, demonstrating exceptional potency for androgen receptor binding. S-23 binds to the AR (Ki = 1.7 nM) and induces AR-mediated transcriptional activation in CV-1 cells, confirming its mechanism as an AR agonist. It binds to the androgen receptor more strongly than older drugs such as andarine with a Ki of 1.7 nM, demonstrating superior potency compared to earlier-generation SARMs. S23 SARM is a nonsteroidal selective androgen receptor modulator (SARM) known for its potency, closely resembling that of anabolic steroids, providing steroid-like effects without steroidal structure. S-23 is a type of chemical known as a selective androgen receptor modulator (SARM) that mimics the activity of testosterone in the body, providing comprehensive androgenic effects. In animal studies, S-23 showed both a good ratio of anabolic to androgenic effects, and dose-dependent suppression of spermatogenesis with spontaneous recovery after cessation of treatment, confirming its dual therapeutic potential for muscle growth and male contraception. Administration of S-23 to castrated animals increases the weights of the androgen-dependent organ dose-dependently with the ED₅₀s of S-23 in the prostate and levator ani muscle of 0.43 and 0.079 mg/d, respectively, demonstrating potent tissue-specific anabolic effects. S-23 increases prostate, seminal vesicle, and levator ani muscle weights in castrated rats, confirming broad androgenic tissue activation. The compound has been shown to increase female libido, promote anabolic activity in muscles and bone tissue, and act as a male contraceptive, demonstrating comprehensive therapeutic applications. S-23 is an effective and reversible agent for hormonal male contraception in rats, confirming its potential as a male contraceptive. S-23 is used to increase energy, improve athletic performance, increase muscle growth, and for other uses, demonstrating broad research applications. This potent SARM mechanism positions S-23 as a critical tool compound for investigating muscle growth research, lean body mass preservation studies, bone mineral density enhancement pathways, male hormonal contraception models, increased female libido studies, anabolic activity in muscle and bone tissue, athletic performance enhancement, and potent androgen receptor signaling in preclinical models, offering potential therapeutic insights with steroid-like potency but nonsteroidal structure. S-23 is banned by the World Anti-Doping Agency (WADA) and the National Collegiate Athletic Association (NCAA), and there have been reports of liver damage, heart attack, and stroke after use, confirming significant safety concerns for human use.

Handling & Storage Guidelines

• Long-Term Storage: Store powder at -20°C (-4°F) for up to 3 years for optimal stability; in solvent at -80°C for 1 year. Minimize open air exposure; store in cool, dry place; protect from light and moisture; PET single-wall jar provides UV resistance; shelf life 36 months at -20°C

• Solubility: DMSO: 250 mg/mL (599.88 mM, sonication recommended); Polyglycols: soluble; 10% DMSO + 40% PEG300 + 5% Tween 80 + 45% Saline: 10 mg/mL (24 mM, suspension); dissolve by heating/sonication if necessary; add solvents sequentially; clarify solution before adding next; working solution prepared and used immediately; aqueous solutions have limited solubility

• Appearance: White to off-white powder; clear solutions in DMSO and polyglycols when properly dissolved; relative density 1.48 g/cm³ (predicted)

Global Logistics & Order Fulfillment

We proudly support scientific advancement across all 50 U.S. states and throughout Europe. Customers can seamlessly toggle their preferred currency between USD and EUR using the currency switcher located on the left-hand side of our website. All shipments are securely packaged to withstand international transit without compromising structural or chemical stability.

Laboratory Use Only Disclaimer

This material is sold strictly for laboratory research and development use only. It is not approved for human consumption, nor for medical, veterinary, or household applications. All purchases are governed by our standard Terms & Conditions. Please review them carefully before placing your order.