Insulin
Exogenous insulin used in bodybuilding to shuttle glucose and amino acids into muscle cells. Extremely potent at glycogen supercompensation and anti-catabolism but carries the highest acute lethality risk of any PED due to hypoglycemia.
Mechanism of Action
Activates the insulin receptor, triggering the PI3K/Akt signaling cascade. Drives glucose transporter (GLUT4) translocation to the cell membrane, dramatically increasing glucose uptake into muscle cells for glycogen storage. Simultaneously shuttles amino acids into muscle tissue, enhancing protein synthesis. Strongly anti-catabolic — suppresses cortisol-mediated protein breakdown. Does NOT interact with androgen receptors.
Typical Dosing
⚠ Warning Flags
- •LETHAL IF MISUSED — hypoglycemia can cause seizures, coma, and death within minutes
- •Must always have fast-acting carbohydrates on hand
- •Promotes significant fat gain if diet is not meticulously controlled
- •Not recommended for anyone without advanced nutrition knowledge
- •Never use alone — always with someone present who can intervene
Effect Profile
Side Effect Profile
Research Studies
An abundant supply of amino acids enhances the metabolic effect of exercise on muscle protein
Biolo G et al. · 1995
Demonstrated that insulin combined with amino acid availability significantly stimulates muscle protein synthesis above exercise alone.
Insulin, growth hormone and sport
Sonksen PH · 2001
Reviews the anabolic mechanisms of insulin in athletic contexts, documenting its effects on glucose and protein metabolism.
Insulin use by bodybuilders
Rich JD et al. · 1998
Documents real-world PED use of insulin by bodybuilders and the associated hypoglycemia risks.