The honest answer
The muscle-repair signalling piece.
Short answer
MGF (mechano growth factor) is a peptide studied in preclinical research for muscle-repair signalling. In BPC Matrix it covers the muscle side of recovery on top of the BPC-157 base. Studied, not proven; individual results vary.
Soft-tissue recovery involves muscle too. MGF has been studied around muscle-repair signalling, which is the part it covers in the blend.
BPC-157 (blood supply) + TB-4 (cell migration) + KPV (inflammation) + MGF (muscle) — four peptides, four parts of repair. See the blend.
Straight answers
It has been studied for muscle-repair signalling. Individual results vary; nothing here is a medical claim.
No — it is not an FDA-approved drug and is physician-supervised.