http://www.mesomorphosis.com/article...cle-growth.htm
This part is interesting to me because it talks about using a virus as a vehicle to deliver IGF1 over long periods. It's working in mice so far.
The results of this study are similar to other studies where IGF-1 was injected directly into muscle tissue, resulting in increases in size and strength of experimental animals. Using a virus as a genetic vehicle has an advantage over simply injecting the growth factor. The effects of a single viral treatment last significantly longer (months if not years) because the muscle cell itself is constantly overproducing its own IGF-1 from injected DNA.
The fact that the IGF-1 produced by the muscle of these mice did not reach the blood stream is interesting. Systemic injections of IGF-1 have not been successful in inducing this kind of anabolic effect in humans. In addition, IGF-1 produced by the liver is genetically different than that produced by muscle tissue. It could be that providing additional DNA for the muscle to produce it’s own IGF-1 is the key to achieving anabolic and rejuvenative effects specifically in skeletal muscle.