Which hormone does not stimulate lipolysis?

Lipolysis is the metabolic process through which triglycerides are broken down into glycerol and free fatty acids, primarily to be used for energy. Insulin plays a crucial role in the regulation of glucose and fat metabolism. When insulin levels are elevated, such as after a meal, it promotes the storage of energy by facilitating glucose uptake into cells and encouraging the synthesis of fatty acids and triglycerides. As a result, insulin inhibits lipolysis by decreasing the activity of hormone-sensitive lipase (HSL), the enzyme responsible for breaking down stored fats in adipose tissue.

In contrast, hormones like glucagon, epinephrine, and cortisol promote lipolysis. Glucagon, released during fasting or low blood glucose situations, activates lipolysis to provide free fatty acids for energy. Epinephrine, often released in response to stress or physical activity, also stimulates lipolysis to mobilize energy sources quickly. Similarly, cortisol, a glucocorticoid hormone, promotes lipolysis as part of the body's response to stress, helping to provide additional energy during prolonged fasting or stress.

Thus, the significant inhibitory effect of insulin on fat breakdown firmly establishes it as the hormone that does not stimulate lipolysis, making it the correct answer