Glucagon
A hormone made by the pancreas that raises blood sugar by releasing glucose stored in the liver, acting as the antagonist of insulin.
Glucagon is the mirror image of insulin. Where insulin lowers blood sugar (storage), glucagon raises it (release). When blood sugar falls (fasting, between meals, during exercise), the pancreas secretes glucagon, which tells the liver to release its glycogen and make glucose.
The original angle (the regulation duo): insulin and glucagon form a permanent balancing system that keeps blood sugar stable:
- After a meal: glucose ↑ → insulin ↑, glucagon ↓ → storage
- When fasting: glucose ↓ → insulin ↓, glucagon ↑ → release and fat burning
Glucagon is therefore the hormone of “destocking” mode. It activates lipolysis (fat burning) and ketone production. This is why fasting phases (high glucagon) favour the use of fat.
The modern imbalance: constant snacking keeps insulin high and glucagon low. You stay stuck in “storage” mode, never switching to “destocking/fat-burning” mode. Spacing out meals lets glucagon do its job.
The role of protein (a nuance): unlike carbohydrates (which stimulate insulin), protein stimulates BOTH insulin AND glucagon. The latter “counterbalances” insulin, preventing hypoglycaemia. It is one of the mechanisms that make protein filling and stabilising for blood sugar.
Medical application: injectable glucagon is the emergency treatment for severe hypoglycaemia in people with diabetes (it raises blood sugar quickly).