LGD-3303

LGD-3303 (Selective Androgen Receptor Modulator)

LGD-3303 is a synthetic, nonsteroidal, orally bioavailable Selective Androgen Receptor Modulator (Selective Modulator) originally developed by Ligand Pharmaceuticals. It is characterized as a high-affinity androgen receptor ligand featuring a unique tricyclic pyrrolo[3,2-f]quinolin-7-one fused ring system. LGD-3303 is widely recognized in laboratory research for its tissue-differential activity, acting as a full agonist in muscle and bone tissue models while exhibiting partial agonist activity in prostate-derived reporter models.

Technical Specifications

Mechanism of Action & Scientific Context

LGD-3303 binds the androgen receptor (AR) ligand-binding domain with high affinity (Ki ≈ 0.9 nM). Its structural design—incorporating a chlorine atom and a trifluoroethyl group—influences its metabolic stability and receptor binding kinetics.

Functional Selectivity:

Unlike many steroidal ligands, LGD-3303 induces a distinct ligand-binding domain conformation upon binding. This facilitates tissue-differential transcriptional output, making it an essential tool for studies comparing AR signaling across muscle, bone, and prostate-derived cell lines.

Research Applications

LGD-3303 serves as a foundational reference ligand in androgen receptor pharmacological research and analytical method development.

Primary fields of in vitro laboratory investigation include:

• Receptor Pharmacology: Androgen receptor binding and competition assays.

• Structure-Activity Relationship (SAR): Comparative analysis of the tricyclic pyrroloquinolinone structural class.

• Nuclear Receptor Selectivity: Profiling specificity across the broader steroid hormone receptor family.

• Conformational Analysis: Investigating ligand-binding domain conformation and coregulator recruitment studies.

• Analytical Method Development: Use as a reference standard for LC-MS/MS panels, including WADA-referenced anti-doping analytical protocols.

Storage & Handling Guidelines

To maintain the stability and purity of the research material, the following protocols are recommended:

• Long-Term Storage: Store powder at -20 °C.

• Active Research: Short-term storage at room temperature is acceptable.

• Environmental Control: Protect from direct light and keep in a tightly sealed container to prevent degradation.

• Moisture Protection: Use desiccant for powder storage.

• Handling: Adhere to appropriate laboratory handling procedures and wear required Personal Protective Equipment (PPE).

Regulatory & Research Use Disclaimer

Research Use Only Disclaimer: This product is developed and distributed strictly as a Research Use Only (RUO) laboratory reference chemical intended exclusively for non-clinical analytical and scientific investigation. It is not intended for human consumption, clinical use, veterinary use, therapeutic application, or diagnostic use. LGD-3303 is included on the World Anti-Doping Agency (WADA) Prohibited List under the anabolic agents category. All handling, preparation, and experimental use must comply with applicable federal, state, and local laws, as well as institutional laboratory safety standards. Kimera Chems supplies this reagent exclusively to qualified researchers and scientific institutions.