The present invention relates to a viscoelastic gel comprising therapeutically effective amount of liraglutide, wherein the gel does not have a block or a graft copolymer, and wherein the gel is characterized by yield value from 200 Pa to 3000 Pa and flow point from 300 Pa to 3500 Pa. The invention also provides method of controlling blood sugar levels by subcutaneously administering such gel once-weekly or once-biweekly to a subject in need thereof. The method of preparation of such gels are also provided.