Kidney

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.

Mineralocorticoid Receptor

The aldosterone receptor in the kidney. When a steroid activates it, sodium and water are held onto, which shows up as blood pressure and smooth-over-the-muscle bloat.

Erythropoietin

The kidney's signal telling marrow to build red cells. Androgens raise it, and it is the upstream cause of the haematocrit rise rather than a separate effect.

Sodium and Water Retention

Holding onto salt and the water that follows it. Shows up as a smoother look, a heavier scale reading and a higher blood pressure.