The highest concentration of this peptide is 4350 ng/mL, and the majority of samples are above the limit of quantification (1 ng/mL). AZP-531 infusion prevents the increase in body weight caused by high-fat diet in mice. AZP-531 treatment prevents high-fat diet-induced proinflammatory effects, stimulates expression of mitochondrial function markers in brown adipose tissue, and prevents development of a prediabetic metabolic state. AZP-531 also prevents a high-fat diet-induced increase in acyl ghrelin levels. AZP-531 is well tolerated. Single- and multiple-dose pharmokinetic variables are similar. Maximum AZP-531 concentrations are typically reached at 1 h post-dose. Observed maximum concentration and area under the curve are dose-proportional. The mean terminal half-life is 2–3 h. AZP-531 (≥15 μg/kg) significantly improves glucose concentrations, without increasing insulin levels, suggesting an insulin-sensitizing effect. AZP-531 decreases mean body weight by 2.6 kg (vs 0.8 kg for placebo). Glucose variables improve in all groups, including placebo, suggesting a study effect in uncontrolled patients at baseline. AZP-531 60 μg/kg reduces HbA1c by 0.4% (vs 0.2% for placebo) and body weight by 2.1 kg (vs 1.3 kg for placebo).