Glucagon

Glucagon is a stress hormone whose primary role is to mobilize stored energy during emergencies, acting in concert with the catecholamines. 2 Danny Roddy has described it as coupled with adrenaline and other catecholamines as a "true emergency hormone," distinguishing its rapid, short-term action from the more sustained, long-term stress responses mediated by cortisol and pituitary hormones. 1 This framing positions glucagon not as an isolated metabolic regulator, but as a central component of a complex biochemical web activated by stressors ranging from psychological disturbance to physical trauma. 4

The hormone's function is to provide substrate when exogenous energy is unavailable, but it does so by acting as a brake on metabolic processes over the long term. 2 Mike Fave noted that glucagon is there to "slow metabolism and to provide substrate in the form of carbohydrate when you don't have anything coming in." 2 Jay Feldman elaborated on a critical temporal dichotomy: in the short term, glucagon can appear to be a "gas pedal" by increasing respiration, but in excessive amounts or over the long term, it is not. 2 This is because glucagon stimulates the synthesis of glucose at the expense of protein and, in turn, stimulates the release of more free fatty acids, creating a vicious cycle. 3

Ray Peat identified that this destructive cycle is specifically triggered by polyunsaturated fatty acids (PUFAs). He explained that free fatty acids inhibit glucose utilization at pyruvate dehydrogenase and stimulate glucagon, which then further increases fatty acid release. 3 This creates an apparently illogical positive feedback loop where an initial energy failure turns on the very mechanisms that caused it. 3 Crucially, Peat distinguished that while PUFAs activate stress hormones like glucagon, adrenaline, and cortisol, saturated fats such as stearic acid inhibit these stress reactions, making the stress response self-limiting in a person with a healthier fat composition. 2

The chronic elevation of glucagon is therefore inseparable from a broader degenerative stress cascade. Roddy cited Hans Selye's work showing that glucagon rises rapidly in response to various stressors, followed by an elevation of blood glucose but not insulin. 4 This state, where glucagon acts without the counter-regulation of insulin, is described as dangerous, contributing to diabetic ketoacidosis, muscle loss, and extremely high levels of glucose, ketones, and free fatty acids. 2 The trajectory of a high-energy, structured organism involves moving away from reliance on these primitive, catabolic hormones. 1 Feldman pointed out that the popular weight-loss drugs, the GLP-1 agonists, function as antagonists to glucagon, highlighting that lowering glucagon, rather than elevating it, is the therapeutic goal for metabolic disease. 6