Which hormone is primarily responsible for regulating blood sugar levels?

Insulin is the hormone primarily responsible for regulating blood sugar levels. It is secreted by the beta cells of the pancreas in response to elevated glucose levels in the bloodstream, particularly after meals. Insulin facilitates the uptake of glucose by body cells, particularly muscle and fat cells, allowing them to use glucose for energy or store it as glycogen for future use. This process effectively lowers the blood sugar level to a normal range.

In addition to its role in blood sugar regulation, insulin also promotes fat storage and the synthesis of proteins. Its primary action is to lower glucose levels, contrasting with hormones like glucagon, which raises blood sugar levels by signaling the liver to convert stored glycogen back into glucose.

Understanding insulin's role is crucial for managing conditions such as diabetes, where insulin production or response is impaired, leading to consistently elevated blood sugar levels.