We investigated the influence of an etonogestrel-releasing (ETG) implant and copper intrauterine device (IUD) on carbohydrate metabolism.In this nonrandomized, open-label, prospective controlled trial, 40 healthy women received an implant or IUD (20 per group). Outcome measures were fasting glucose, fasting insulin, oral glucose tolerance test (OGTT) and glycosylated hemoglobin A 1 C (HbA 1 C) levels at baseline and after 6 and 12 months.The groups were similar in age, body mass index and laboratory parameters at baseline. Carbohydrate metabolism was not modified by the ETG implant at baseline and at 6 and 12 months (mean±SD) (fasting glucose: 85.9±5.13, 87.05±5.36, 88.19±5.05; insulin: 7.77±2.42, 10.64±9.4, 8.82±3.73; OGTT: 94.8±25.28, 96.5±19.67, 99.47±24.6; HbA 1 C: 5.27±.34, 5.55±.39, 5.7±0.37). The same was true for the IUD (fasting glucose: 88.87±7.2, 89.65±5.86, 88.75±4.79; insulin: 7.94±3.6, 8.3±4.1, 7.34±3.02; OGTT: 96.85±15.16, 97.48±13.42, 91.3±22.16; HbA 1 C: 5.41±.49, 5.75±.41, 5.9±0.73).The ETG-releasing implant did not affect carbohydrate metabolism in normal women after 12 months.