Cardarine

Etki Mekanizması

Cardarine acts as a potent and highly selective agonist of PPAR-delta, a nuclear hormone receptor expressed in skeletal muscle, liver, adipose tissue, and the gastrointestinal tract. Upon binding to PPAR-delta, Cardarine triggers a conformational change that promotes heterodimerization with retinoid X receptor (RXR), and the resulting complex binds to PPAR response elements (PPREs) in the promoter regions of target genes. This transcriptional activation upregulates a suite of genes involved in fatty acid oxidation, mitochondrial biogenesis, and energy uncoupling. In skeletal muscle, PPAR-delta activation by Cardarine shifts the metabolic fuel preference from glucose toward fatty acids, dramatically increasing the rate of beta-oxidation. This metabolic reprogramming effectively transforms type II (fast-twitch, glycolytic) muscle fibers toward a more oxidative phenotype, similar to type I (slow-twitch) fibers, which underpins the compound's dramatic effects on endurance capacity. Preclinical studies in mice demonstrated that GW501516 treatment increased running endurance by up to 68% compared to controls. In the liver and adipose tissue, PPAR-delta activation by Cardarine promotes fatty acid catabolism and reduces lipogenesis, resulting in reduced body fat storage and improved lipid profiles (increased HDL, decreased LDL, reduced triglycerides). Critically, Cardarine does not interact with the androgen receptor, does not suppress the hypothalamic-pituitary-gonadal (HPG) axis, and does not affect endogenous testosterone production. This non-hormonal mechanism means it does not cause testosterone suppression and does not require post-cycle therapy.