Mechano growth factor (MGF) is a synthetic version of a small form of insulin-like growth factor-1 (IGF-1). This peptide is also known as IGF-1 Ec in humans and it was originally discovered in growing muscle tissues that were recovering from damage . MGF is up-regulated in damaged and exercising muscle and is likely to stimulate muscle growth since it has been shown to stimulate proliferation of muscle cells and suppress their differentiation [2-4]. No MGF receptor has been found and it is likely that MGF is a peptide that acts inside the cell itself in order to change the production of additional proteins that influence muscle growth and repair . A single intramuscular injection of a gene producing MGF resulted in a 25% increase in muscle fibre cross sectional area in less than three weeks in a mouse model . MGF can therefore be used as an exercise supplement for athletes and bodybuilders trying to increase strength and muscle mass. MGF has also been confirmed to have a positive role on bone injury healing in injured white rabbits, where injecting MGF peptide into the injured bone for five days resulted in faster bone healing . Furthermore, increased expression of MGF was detected during the prolonged extension of the Achilles tendons of rats . These experiments confirm the role of MGF as a local tissue repair peptide and indicated that it is responsive to mechanical stimulation. MGF has also been shown to play a neuroprotective role in damaged brain cells and was shown to be present in various brain tissues . In muscle cells, MGF is known to stimulate stem cells to grow and replicate into new muscle fibres . The production of MGF also leads to an upregulation of protein synthesis to build new muscle. Moreover, release of MGF results in the production of IGF-1Ea from the liver, which also works to upregulate protein synthesis to aid in muscle growth and the repair of damaged muscle tissue. MGF decay has never been measured in humans, but it is estimated to have a very short half-life when administered orally or via injection . The limited half-life means that MGF should be directly injected into multiple points along each muscle once it has been reconstituted in BAC water. Between 100-300 mcg of MGF should be divided between 2-4 muscles each day for best results. It is best to administer the peptide 2 hours after training and at least 2 hours before sleeping to prevent disruption of natural growth hormone production during sleep. MGF has not been tested for its safety in human clinical trials, but it is naturally found in human muscle and has been shown to be well-tolerated in animal studies at doses up to 10 mcg/kg. Some minor side effects that may occur following MGF injection include facial flushing and nausea. References 1. Goldspink, G., Research on mechano growth factor: its potential for optimising physical training as well as misuse in doping. Br J Sports Med, 2005. 39(11): p. 787-8; discussion 787-8. 2. McKoy, G., et al., Expression of insulin growth factor-1 splice variants and structural genes in rabbit skeletal muscle induced by stretch and stimulation. The Journal of Physiology, 1999. 516(Pt 2): p. 583-592. 3. Yang, S., et al., Cloning and characterization of an IGF-1 isoform expressed in skeletal muscle subjected to stretch. J Muscle Res Cell Motil, 1996. 17(4): p. 487-95. 4. Yang, S.Y. and G. Goldspink, Different roles of the IGF-I Ec peptide (MGF) and mature IGF-I in myoblast proliferation and differentiation. FEBS Lett, 2002. 522(1-3): p. 156-60. 5. Schlegel, W., et al., Insulin-Like Growth Factor I (IGF-1) Ec/Mechano Growth Factor � A Splice Variant of IGF-1 within the Growth Plate. PLoS ONE, 2013. 8(10): p. e76133. 6. Goldspink, G., Research on mechano growth factor: its potential for optimising physical training as well as misuse in doping. British Journal of Sports Medicine, 2005. 39(11): p. 787-788. 7. Deng, M., et al., Mechano growth factor E peptide promotes osteoblasts proliferation and bone-defect healing in rabbits. Int Orthop, 2011. 35(7): p. 1099-106. 8. Heinemeier, K.M., et al., Effect of unloading followed by reloading on expression of collagen and related growth factors in rat tendon and muscle. J Appl Physiol (1985), 2009. 106(1): p. 178-86. 9. Dluzniewska, J., et al., A strong neuroprotective effect of the autonomous C-terminal peptide of IGF-1 Ec (MGF) in brain ischemia. Faseb j, 2005. 19(13): p. 1896-8. 10. Hill, M. and G. Goldspink, Expression and splicing of the insulin-like growth factor gene in rodent muscle is associated with muscle satellite (stem) cell activation following local tissue damage. J Physiol, 2003. 549(Pt 2): p. 409-18.