Which hormone causes the conversion of glycogen to raise blood sugar level?

The hormone responsible for the conversion of glycogen to raise blood sugar levels is glucagon. It plays a crucial role in glucose metabolism. When blood sugar levels fall, glucagon is released from the alpha cells of the pancreas. Its primary function is to stimulate the liver to break down glycogen—stored glucose—into glucose and release it into the bloodstream. This process, known as glycogenolysis, effectively increases blood sugar levels, countering hypoglycemia.

The other hormones listed do not serve this purpose. Testosterone is primarily involved in the development of male sexual characteristics and muscle mass, while oestrogen is crucial for female reproductive health and various functions in both males and females. Insulin, on the other hand, lowers blood sugar levels by facilitating the uptake of glucose into cells and promoting the storage of glucose as glycogen, rather than increasing blood sugar levels through glycogen breakdown.