IGF Long R3 is IGF-1 which has been chemically altered and has had amino acid changes which cause it to avoid binding to proteins in the human body and allow it to have a much longer half life, around 20-30 hours.
Long R3 IGF-1 is an 83 amino acid analog of IGF-1 comprising the complete human IGF-1 sequence
With the substition of an Arg(R) for the Glu(E) at position three, hence R3, and a 13 amino acid extension peptide at the N terminus.
This analog of IGF-1 has been produced with the purpose of increasing the biological activity of the IGF peptide.
The following is piecemeal from a column in Muscular Development and provides interesting information on dosing/efficacy/side effects:
However, what bodybuilders started noticing after extended usage of Long R3 IGF-1 was that it stopped working as effectively after about 4 weeks.
Moreover, as the dosage of IGF-1 increases above the suggested 10-20 mcg per day, the IGF-1 muscle cell receptors become saturated and now all this excess IGF-1 goes straight to the highest naturally occuring concentration of IGF-1 receptors - the extremities (I.e feet, hands and facial bones).
Thereby, side effects such as shoe and hand size increases and facial bone thickening can occur. Additionally, high Long R3 IGF-1 dosing will lead to decreases in muscle cell IGF-1 receptors, thus diminishing the results seen with Long R3 IGF-1 usage over time.
In summation, empirical evidence has shown that 10-20mcg per day of Long R3 IGF-1 causes significant muscle cell hyperplasia and will continue to do so extremely effectively for approximately 30 days.
However, even with conservative amounts of Long R3 IGF-1, the hormone still stops functioning after a period of time.
Ultimately the author recommended short cycles of low doses of the drug with frequent holidays, and the magazine also states that it’s human safety is still undetermined.
I’m not poo-pooing anybody, just remember to be careful and do your research on these things, especially with dosing and duration; facial bone thickening is not a reversible side effect.