Generalized lipodystrophy (GL) is a rare inherited or acquired disease characterized by widespread loss of subcutaneous fat, leading to leptin deficiency, ectopic fat deposition, and severe metabolic abnormalities. Previous studies have shown the benefit of leptin replacement (metreleptin) in ameliorating metabolic complications, but little is known about the experience of metreleptin treatment outside of a research setting. We report on post-marketing clinical experience with metreleptin therapy in three patients with GL and marked hypoleptinemia, uncontrolled diabetes, and hypertriglyceridemia. After metreleptin treatment for 12-168 weeks, the mean glycated hemoglobin decreased from 10.9% to 5.8%, and serum triglycerides were normalized (a mean decline of 90%). These benefits were observed within weeks of starting therapy, were durable, and were accompanied by subjective improvements in quality of life, decreased need for concomitant medications, and no significant adverse effects. Metreleptin was safe and effective in normalizing certain severe metabolic abnormalities in the clinic setting.