Which hormone regulates blood sugar levels in the body?

Insulin is the hormone that plays a crucial role in regulating blood sugar levels in the body. Produced by the pancreas, insulin facilitates the uptake of glucose from the bloodstream into the cells, where it can be used for energy or stored for future use. When blood sugar levels rise after eating, insulin is released to help lower these levels back to a healthy range. This regulation is vital for maintaining homeostasis and ensuring that the body functions properly.

In contrast, other hormones listed are involved in different bodily functions. Adrenaline, for instance, is associated with the body's fight-or-flight response and increases energy availability by promoting the release of glucose into the bloodstream, but it does not directly regulate blood sugar levels in the same way that insulin does. Cortisol, a hormone released in response to stress, can increase blood sugar levels as part of the stress response, but it does not regulate them. Testosterone is primarily known for its role in the development of male sexual characteristics and does not have a direct influence on blood glucose regulation.