Aims: Optimisation of glycaemic control in type 1 diabetes often results in unwanted weight gain. glucagon-like peptide-1 (GLP-1) agonist use is associated with weight reduction in type 2 diabetes but its use in type 1 diabetes is little studied. Methods: We developed a protocol for GLP-1 use in people with type 1 diabetes and obesity in which liraglutide was initiated and up-titrated whilst insulin doses were simultaneously titrated according to glycaemic parameters. Results: Of 15 patients offered treatment, 8 proceeded. Baseline parameters were (n=8, mean + SD): (age 50 ± 6 years, BMI 40.4 ± 5.5 kg/m2, weight 123.0 ± 23.9 kg, HbA1c 8.5 ± 1.7%, total daily insulin dose 131 ± 112 units/day. By intention to treat analysis (n=8, 12 months), at 3, 6 and 12 months compared to baseline, weight loss was 6.8 ± 4.1 kg, 10.0 ± 5.6 kg and 8.9 ± 8.4 kg (p=0.026). The reductions in insulin dosage were significant over 6 months (n=8, p=0.045) or when analysing only those who completed 12 months of liraglutide therapy (n=6, p=0.044). Conclusions: GLP-1 agonist use in patients with type 1 diabetes may be advantageous where weight reduction becomes both a constraint and a therapeutic objective.