Seladelpar is an orally active, potent (50% effect concentration EC50 2 nM), and specific PPAR-δ agonist. Seladelpar (MBX-8025) is an orally active, potent (2 nM), and specific (>750-fold and >2500-fold compared with PPAR-α or PPAR-γ receptors, respectively) PPAR-δ agonist being developed as a lipid-altering agent. Seladelpar is a potent, and selective PPAR-δ agonist (50% effect concentration human PPAR-δ=2 nM, PPAR-α=1,600 nM) that demonstrates favorable effects on insulin resistance, diabetes, and atherogenic dyslipidemia. From weaning, female Alms1 mutant (foz/foz) mice and wild-type littermates are fed an atherogenic diet for 16 weeks; groups (n=8-12) are then randomized to receive Seladelpar (10 mg/kg) or vehicle (1% methylcellulose) by gavage for 8 weeks. Despite minimally altering body weight, Seladelpar normalizes hyperglycemia, hyperinsulinemia, and glucose disposal in foz/foz mice. Serum alanine aminotransferase ranges 300-600 U/L in vehicle-treated foz/foz mice; Seladelpar reduces alanine aminotransferase by 50%. In addition, Seladelpar normalizes serum lipids and hepatic levels of free cholesterol and other lipotoxic lipids that are increased in vehicle-treated foz/foz versus wild-type mice. This abolished hepatocyte ballooning and apoptosis, substantially reduce steatosis and liver inflammation, and improve liver fibrosis. In vehicle-treated foz/foz mice, the mean nonalcoholic fatty liver disease activity score is 6.9, indicating nonalcoholic steatohepatitis (NASH); Seladelpar reverses NASH in all foz/foz mice (nonalcoholic fatty liver disease activity score 3.13). In atherogenic diet-fed Wt mice, administration of Seladelpar reduces body weight by ∼18% (Pfoz/foz mice. These animals develope severe hyperglycemia, hyperinsulinemia, and whole-body insulin resistance after 16 weeks (Pfoz/foz mice (Pfoz/foz mice (PWt mice (P<0.05).