Cardarine (GW-501516)

Nuclear receptor pharmacology

PPARδ is a ligand-activated transcription factor that partners with the retinoid X receptor and binds peroxisome proliferator response elements in target gene promoters. Unlike PPARγ, which is concentrated in adipose tissue, PPARδ is expressed widely, with notable levels in skeletal muscle. GW-501516 is used in cell and tissue work as a reference agonist for this receptor because of its selectivity over the alpha and gamma subtypes, and it appears frequently in studies that need a tool compound to switch the PPARδ programme on.

• Transcriptional induction of genes in fatty-acid uptake and beta-oxidation, including PDK4, CPT1 and UCP family members
• Substrate-selection questions — whether receptor activation shifts cultured myotubes and rodent muscle toward lipid rather than glucose utilisation
• Lipoprotein endpoints in obese and insulin-resistant animal models and in early human study
• Inflammatory and vascular endpoints in cell models expressing PPARδ

Analytical and anti-doping literature

A substantial body of method work exists for detecting the parent compound and its sulfoxide and sulfone metabolites in urine and blood by LC-MS/MS, driven by anti-doping surveillance. Related research covers long-detection-window assays, reference-standard characterisation, and screening of consumer products, where independent analyses have repeatedly reported mislabelled or contaminated material.

Store capsules in the original sealed bottle with any desiccant at room temperature, dry and away from light. Keep the liquid presentation upright with the cap firmly closed, and inspect for clarity before use — solvent loss from an open bottle concentrates the solution. Because this compound carries a published carcinogenicity signal, weigh powder or open capsules only inside a fume hood or ventilated enclosure, wear gloves and eye protection, and avoid generating dust or aerosols. Label every working solution with compound, concentration, solvent, lot and date, and dispose of surplus material and contaminated consumables as hazardous chemical waste under your institutional procedures.