HGH is better i think most would say - but IGF definitely has positive effects on muscle growth - whether that is actually hyperplasia or not i would need biopsies to tell! (of studies done on rodents, hyperplasia is definitely taking place, and i know that IGF does have a role in cell proliferation/differentation - i will paste ‘some’ article i had saved on my disc at the bottom of this post, as while i understand the process at this time, i would struggle to explain it in full from memory!
Anyway - GH increases IGF too and is supposedly a large factor in GH’s anabolism. I am sure there are other factors at play there too. Plus GH does so much more… increases lipolysis, increases collagen synthesis…
I use peptides - not due to price really, as although they are cheaper, GH isn’t too expensive either. I use them because they suit my goals plenty for the time being (i would use Gh if i could afford to run it as frequently as i can afford to run IGF). As i near bodybuilding competitively i will begin to use GH more. That is not to say i believe it should be reserved for competitive BB’s - far from it (IMO less so than AAS would/should/could be), just that is how i choose to do things.
I do believe that IGF does have some insulin like activity (surprised?!) when it comes to blood glucose - although the details i am not ‘up’ on. All i know is that at 20mcg a day it has no noticeable effect WRT hypoglycaemia symptoms. When i once shot 100mcg - i still noticed nothing in the way of hypo like symptoms either. I am aware that some people have claimed to have gone hypo from a shot of IGF - i suspect they may have been low carb dieters, due to my experiences.
EDIT: Funnily enough - today is a day off from the gym (so far at least!) and i just shot my 20mcg of IGF-1 LR3 IM Bilaterally as per usual. However i did it soon after a trip to my Town so i had a fairly empty stomach.
I shot and continued about some things i was messing with - then as i sat down to eat, maybe 10-20mins later i realsied i was shaking and felt an ever so slight but noticeable (to me) hypo feeling. So there you go, it does seem to do it enough to notice and i would imagine a 100mcg shot on an empty stomach would be more severe.
The thing with me is i am or was a natural Ectomorph, so i generally have carbs in me 24/7!!
Take it for what it’s worth.
[quote][b]When the sarcolemma (the muscle cell wall) is Ã¢??damagedÃ¢?? by tension (as in weight training or even stretching) growth factors are produced and released in the cell. There are several different types of growth factors. The most significant are:
Insulin-like Growth Factor 1 (IGF-1)
Fibroblast Growth Factor (FGF)
Transforming Growth Factor -Beta Superfamily (TGF-beta)
These growth factors can then leave the cell and go out into the surrounding area because sarcolemma permeabilty has been increased due to the Ã¢??damageÃ¢?? done during contraction. Once outside the muscle cell these growth factors cause the satellite cells to proliferate (mainly FGF does this) and differentiate (mainly IGF-1 does this). TGF-beta actually inhibits growth Ã¢?? but everything canÃ¢??t be perfect. After this process the satellite cells then fuse with the muscle cells and donate their nuclei. The muscle cell can now grow.
So now factors that promote protein synthesis such as IGF-1, growth hormone (GH), testosterone and some prostaglandins can go to work. How does that all happen? Read onÃ¢?Â¦
Protein synthesis occurs because a genetically-coded subtsance called Ã¢??messenger RNAÃ¢?? (mRNA) is sent out from the nucleus and goes to organelles called Ã¢??ribosomesÃ¢??. The mRNA contains the Ã¢??instructionsÃ¢?? for the ribosomes to synthesize proteins, and so the process of constructing contractile (actin and myosin) and structural proteins (for the other components of the cell) from the amino acids taken into the cell from the bloodstream is set off. Several substances can influence this process. A short overview of the major ones are found below:
IGF-1: IGF-1 comes in two varieties Ã¢?? actually, they are both the same molecule but come from different places. paracrine IGF-1 (also called Ã¢??systemicÃ¢?? IGF-1) is made primarily in the liver and autocrine IGF-1 (also called Ã¢??localÃ¢?? IGF-1) is made locally in other cells (itÃ¢??s called Ã¢??localÃ¢?? IGF-1 because it isnÃ¢??t released in large quantities into the bloodstream Ã¢?? it stays in the area in which it was made). Cells donÃ¢??t let systemic IGF-1 in unless they want to (there are Ã¢??pickyÃ¢?? receptors on the cell wall) but the IGF-1 that was manufactured and released in the muscle cell as a response to the high tension contractions can do itÃ¢??s thing because itÃ¢??s already inside. So, once in the cell, IGF-1 interacts with calcium-activated enzymes and sets off a process that results in protein synthesis (and the calcium ions that were released during muscle contraction and also the ones that leak into the muscle after the sarcolemma is damaged by training ensure that the necessary enzymes are activated).
A large part of this increase in protein synthesis rate is due to the fact that the IGF-1/calcium/enzyme complexes make protein synthesis at the ribosomes more efficient.
By the way, insulin works at the ribosome in a similar manner, hence the name insulin-like growth factor-1 (IGF-1). So get some quick digesting carbs in after your workout to raise insulin levels.
GH is thought to work, primarily, by causing the cells (muscle cells included) to release IGF-1.
Certain prostaglandins are released during contraction (and stretch); two of the most significant to growth being PGE2 and PGF2-alpha. PGE2 increases protein degradation, whereas PGF2-alpha increases protein synthesis. But PGE2 isnÃ¢??t all bad because it also powerfully induces satellite cell proliferation and infusion. The mechanism of PGF2-alphaÃ¢??s action is much less clear but is suspected to be connected to increasing protein synthesis Ã¢??efficiencyÃ¢?? at the ribosomes also.
And the Granddaddy of them all: testosterone. Ã¢??FreeÃ¢?? testosterone (the kind that isnÃ¢??t bound to some other substance) travels freely across the muscle cell membrane and, once inside, activates whatÃ¢??s called the Ã¢??androgen receptorÃ¢??. Ã¢??BoundÃ¢?? testosterone must first activate receptors on the cell surface before it can enter (the number of receptors on the surface is what controls this pathway). Once the androgen receptor is activated by testosterone it travels to the nucleus and sets off the protein synthesis process. In this way, testosterone directly causes protein synthesis and is, by far, the most powerful anabolic agent found naturally in the human body. Testosterone also increases the satellite cellsÃ¢?? sensitivity to IGF-1 and FGF, thereby promoting satellite cell proliferation and differentiation. It also increases the bodyÃ¢??s systemic output of GH and IGF-1.
And, guess what, after a workout the muscle cells are more Ã¢??receptiveÃ¢?? to testosterone, systemic IGF-1 and GH Ã¢?? itÃ¢??s almost as if the muscle Ã¢??knowsÃ¢?? that it needs to grow.[/b][/quote]