This was written by a guy who has researched this stuff for 13 years and followed the work of Dave Palumbo and seems to be the best information out there on IGF-1 LR3.
"What do we want? Bigger muscles. More muscle cells that we will later grow with exercise and gear. A pump? Fatloss? Yeah, right. You can get a pump with a good "pump" product for a quarter of the price of IGF-1. Fatloss? Clen/Alb and T3/T4 will give it to you again at a fraction of the price of IGF-1. More muscle cells, you can ONLY get with IGF-1 (and MGF too). Nothing else will give it to you and if you are using IGF-1 for anything else, you are misusing it. More muscle cells is CLEARLY the best use for IGF-1.
What does all this tell us?
It tells us that we should use IGF-1 to make more muscle cells. It's the only thing that can give it to us and more cells is more growth, which is our goal.
What does this tell us?
The localized effects are the best. Long R3 IGF-1 can float around your body and attach to anything that has IGF-1 receptors. The intestines is the place that has the MOST IGF-1 receptors and it also happens to have lots of blood flow. Injecting large amounts of Long R3 ENSURES that you are growing your intestines. Remember, more cells doesn't equal more size right away. Wait a bit, and see them grow.
What does this mean?
It means that if you are injecting upwards of 50mcg of IGF-1 you are growing your intestines. Yes you are also growing muscle and you may be getting leaner in the process. Your waistline looks trimmer. Nice. A few months down the line, your new intestinal cells will be of their full adult size and you will have acquired the perma-bloat look. Guaranteed. Maybe not Coleman-size perma-gut, but SOME perma-gut and it will keep growing. Guaranteed. Just as your new muscle cells can keep growing and growing IF you pin IGF-1 in a way to maximize new muscle cell creation.
Heavy resistance exercise strongly upregulates the IGF-1 receptors on the stressed muscle. That means that after your workout, the muscles you trained are at their BEST STATE for receiving IGF-1 and growing many new cells. That's when you pin. This upregulation of IGF-1 receptor during exercise is short-lived. The science is not readily available so I am unable to quote a paper, but within 60 minutes of the last set, the receptors are back at baseline. This means, PIN IMMEDIATELY POSTWORKOUT and you will get your new muscle cells. PIN A LESSER AMOUNT and you will get only new MUSCLE cells out of your IGF-1. Pin more and you will grow other things, including stuff you wish you didn't grow.
All the talk about IGF-1's half-life is UTTER BULLSHIT. It is technicality without any real-world applicability. Yes rhIGF-1 has a "short half-life". But what does it mean? It means that it is either taken up by a cell receptor or bound up by a binding protein in short order. Does it mean that 20 minutes after the IGF-1 is pinned you should pin more because "blood levels are low"? Not by any means. Once it's activated a cell receptor, that's where it initiates a cellular response that will take about 72 hours to be complete and which will consume lots of energy. So the half-life of 20 minutes means NOTHING BECAUSE THE EFFECTS STILL LAST 72 HOURS ALL THE SAME.
What about Long R3 IGF-1?
Yes technically it has a longer half-life. Why? Because it either gets rapidly taken up by a cell receptor or... Just floats around. Until it can find a receptor or is destroyed by the immune system or some other metabolizing mechanism. BUT THIS MEANS ***NOTHING***!!! Why does it mean nothing? BECAUSE once it attaches to a cell receptor, it initiates a cellular response that will take about 72 hours to be complete. THIS CELLULAR RESPONSE IS ALL THAT INTERESTS US. Not "blood levels", that's utter bullshit. As a matter of fact, the one thing YOU DO NOT WANT IS FOR BLOOD LEVELS OF IGF-1 TO BE ELEVATED. Because that means you are growing everywhere and this means first and foremost your guts. Sure it feels like it's working while you're on. Just you wait 9 months and see that you look like Craig Kovacs. Bravo, you now have the biggest intestines in the world.
Half-life means nothing. Localized vs systemic = bad argument. You want localized effects. Period. You get them by pinning immediately postworkout. Period. End of argument.