Anabolic & IGF

IGF-1 analogs, MGF, and follistatin compounds for muscle growth and anabolism.

Follistatin

Follistatin is an endogenous glycoprotein that acts as a potent inhibitor of myostatin and activin, two proteins that limit muscle growth. By binding and neutralizing myostatin, follistatin removes the primary brake on skeletal muscle hypertrophy, enabling significant muscle growth beyond normal physiological limits. It is distinct from its isoforms Follistatin 315 and Follistatin 344 in tissue distribution and binding affinity.

Follistatin 315

Follistatin 315 is a splice variant isoform of follistatin produced by alternative mRNA processing. Unlike Follistatin 344 which is tethered to cell surfaces via heparan sulfate proteoglycans, FST-315 circulates freely in the bloodstream and has broader systemic distribution. It is the predominant circulating form and exerts systemic myostatin inhibition as well as FSH suppression, making it relevant to both muscle growth and reproductive endocrinology.

Follistatin 344

Follistatin 344 is a recombinant form of the endogenous follistatin protein. It inhibits myostatin and activin — the primary negative regulators of muscle growth — potentially removing the genetic ceiling on muscle development. It is one of the most theoretically powerful anabolic compounds but is experimental with limited human data.

IGF-1 DES

IGF-1 DES (also written DES(1-3)IGF-1) is a truncated form of IGF-1 missing the first three amino acids of the N-terminus. This structural change dramatically reduces its affinity for IGF binding proteins (IGFBPs), meaning a far greater fraction remains in its free, active form. IGF-1 DES is estimated to be 10x more potent than standard IGF-1 LR3 at the receptor level locally, making it particularly effective for site-specific muscle growth when injected intramuscularly.

IGF-1 LR3

IGF-1 LR3 is a synthetic analog of Insulin-like Growth Factor-1 with an extended half-life. It is one of the most potent anabolic peptides available, directly stimulating muscle cell hyperplasia and hypertrophy, and is the downstream mediator of many of GH's anabolic effects.

MGF (Mechano Growth Factor)

MGF (Mechano Growth Factor) is a splice variant of IGF-1 that is locally produced in muscle tissue in response to mechanical damage from exercise. It activates muscle satellite cells (stem cells) to proliferate and repair damaged fibers, making it specifically targeted at exercise-induced hypertrophy.

PEG-MGF

PEG-MGF (Pegylated Mechano Growth Factor) is a modified form of MGF (Mechano Growth Factor) where polyethylene glycol (PEG) chains have been attached to extend its half-life from minutes to days. Native MGF is released locally in muscle in response to mechanical stress and quickly degrades. PEGylation allows systemic administration with sustained circulation, enabling whole-body muscle repair and anabolic signaling rather than the purely local effect of native MGF.