Protein Breakdown

Glucocorticoid Receptor

The cortisol receptor. Some androgens bind it too, and whether they act as agonist or blocker at a given tissue is a large part of why compounds with similar AR affinity feel so different.

HPA Axis Activity

The stress axis: hypothalamus to pituitary to adrenal cortex, ending in cortisol. Relevant to mood twice over. A compound that blocks the glucocorticoid receptor removes the brake the axis runs on, and a compound that shuts down the gonadal axis leaves this one carrying more of the load.

Lean Mass Loss

Muscle lost alongside fat during rapid weight loss. Roughly a quarter to a third of the weight lost on a GLP-1 agonist without resistance training is lean tissue, which is why the newer dual agonists are engineered to spare it.

Androgen Receptor

The receptor every anabolic-androgenic steroid is designed to hit. Binding moves it into the nucleus where it switches on genes for muscle protein synthesis, and in other tissues for hair loss, prostate growth and oil production.

Nitrogen Retention

Whether the body is holding more protein than it loses. A practical readout of net anabolism rather than a mechanism in its own right.