The primary hormone that promotes the storage of glucose as glycogen is insulin. Insulin is produced by the pancreas in response to elevated levels of glucose in the blood, such as after a meal.

Here's how insulin promotes glycogen storage:

- Increased Glucose Uptake: Insulin stimulates the cells in the liver and skeletal muscles to take up glucose from the bloodstream.

- Activation of Glycogen Synthase: Insulin activates the enzyme glycogen synthase, which is responsible for adding glucose molecules to glycogen chains.

- Inhibition of Glycogen Phosphorylase: Insulin inhibits the enzyme glycogen phosphorylase, which breaks down glycogen into glucose.

By these mechanisms, insulin ensures that glucose is efficiently converted into glycogen and stored for future use when blood glucose levels drop. In the absence of insulin, or in conditions such as insulin resistance or diabetes, glucose uptake and glycogen synthesis are impaired, leading to elevated blood glucose levels and various health complications.