Taking a drug that turns on the glucagon receptor for a long time might affect how the body manages energy and fat, but scientists aren't totally sure how it works yet.

Blocking the glucagon signal in people with type 2 diabetes might cause weight gain, more fat in the liver, and higher blood fat levels — suggesting this hormone helps control how the body uses energy and fat.

Blocking the hormone glucagon with drugs might actually make things worse for people — causing weight gain, higher blood pressure, and more liver fat.

Activating the glucagon receptor in humans leads to higher energy expenditure at rest and a faster heart rate while at rest.

Glucagon might help people eat less and lose weight on its own, even if it's not affecting blood sugar — but scientists used to ignore this idea because of old beliefs about how metabolism works.

Even though glucagon was once thought to be bad for you because it raises blood sugar and stresses the heart, turning it on purpose — especially with other hormones — might actually help your metabolism.