O
Osie
Diamond
Contributor
- Joined
- Nov 15, 2022
- Posts
- 1,320
- Reputation
- 1,133
(This is a very short and rushed thread) TLDR: IGF-1 LR3 can not increase serum IGF-1 levels and can reduce it and it is hypothesized to only bind to the IGF-1 receptors in our muscles but that's unproven.
I was on a forum called MesoRx (informational pharmaceutical forum), and I asked whether IGF-1 LR3 has any effects on serum IGF-1 levels. A member on the forum called Type-IIx who is highly educated in all things HGH, steroids, and peptides, answered my question and said this:
RhIGF-I (mecasermin; e.g., Increlex) is the only IGF that will increase serum IGF-I.
LR3 IGF-I is a different peptide. It is an analog of IGF-I that contains a 13-amino acid extension at the NH₃-terminal end consisting of Met-Phe-Pro-Ala-Met-Pro-Leu-Ser-Ser-Leu-Phe-Val-Asn and has an arginine substitution for a glutamic acid at residue 3. As a result, it is resistant to IGFBP binding (like @enchanted_elixir said), dramatically reducing its biological half-life, and necessitating frequent multiple daily injections to achieve any biological effect (marked by hypoglycemia on par with rhIGF-I).
The reason that you should expect, if anything, reduced serum IGF-I concentrations on bloodwork is because LR3 in most assays is not crossreactive with IGF-I, & because it rapidly clears circulation due to lack of IGFBP binding.
Here is evidence of it lowering serum IGF-I: Gehrig SM, Ryall JG, Schertzer JD,Lynch GS. Insulin-like growth factor-I analogue protects muscles of dystrophic mdx mice from contraction-mediated damage. Exp Physiol. 2008 Nov;93(11):1190-8. doi: 10.1113/expphysiol.2008.042838. Epub 2008 Jun 20. PMID: 18567600.
Other notable effects were that, given continuous 24-hour infusion in rats, it had no significant effect on muscle contractile properties, mass, force capacity,
nor specific force, it decreased median myofiber cross-sectional area, indicating that IGFBP interaction is needed to maintain or augment muscle myofiber size.
And even if you access legit IGF-1 which is called Increlex, if you have any underlying genetic IGF-1 receptor issues, causing you not to respond well to HGH, Increlex still hasn't been shown that effective even in the context in which it is supposed to be used in. A study called "Profile of mecasermin for the long-term treatment of growth failure in children and adolescents with severe primary IGF-1 deficiency" exposes this fact as it reveals that in all the studies in which Increlex has been used, it has not been proven to be effective at causing height growth and can not be used as a substitute to HGH yet, with the efficacy that it's currently showing!
All in all, we've been fooled by the idea of IGF-1 LR3, thinking it would be a possible gateway to faster heightmaxxing gains, but in reality, it's nothing more than a waste of time. However, I could be wrong, we do need to see more people try LR3 and check their serum IGF-1 levels to get more of a definitive idea but it's not looking good so far. IGF-1 Des may have more potential since it's closer to the actual IGF-1 peptide than LR3!
I was on a forum called MesoRx (informational pharmaceutical forum), and I asked whether IGF-1 LR3 has any effects on serum IGF-1 levels. A member on the forum called Type-IIx who is highly educated in all things HGH, steroids, and peptides, answered my question and said this:
RhIGF-I (mecasermin; e.g., Increlex) is the only IGF that will increase serum IGF-I.
LR3 IGF-I is a different peptide. It is an analog of IGF-I that contains a 13-amino acid extension at the NH₃-terminal end consisting of Met-Phe-Pro-Ala-Met-Pro-Leu-Ser-Ser-Leu-Phe-Val-Asn and has an arginine substitution for a glutamic acid at residue 3. As a result, it is resistant to IGFBP binding (like @enchanted_elixir said), dramatically reducing its biological half-life, and necessitating frequent multiple daily injections to achieve any biological effect (marked by hypoglycemia on par with rhIGF-I).
The reason that you should expect, if anything, reduced serum IGF-I concentrations on bloodwork is because LR3 in most assays is not crossreactive with IGF-I, & because it rapidly clears circulation due to lack of IGFBP binding.
Here is evidence of it lowering serum IGF-I: Gehrig SM, Ryall JG, Schertzer JD,Lynch GS. Insulin-like growth factor-I analogue protects muscles of dystrophic mdx mice from contraction-mediated damage. Exp Physiol. 2008 Nov;93(11):1190-8. doi: 10.1113/expphysiol.2008.042838. Epub 2008 Jun 20. PMID: 18567600.
Other notable effects were that, given continuous 24-hour infusion in rats, it had no significant effect on muscle contractile properties, mass, force capacity,
nor specific force, it decreased median myofiber cross-sectional area, indicating that IGFBP interaction is needed to maintain or augment muscle myofiber size.
And even if you access legit IGF-1 which is called Increlex, if you have any underlying genetic IGF-1 receptor issues, causing you not to respond well to HGH, Increlex still hasn't been shown that effective even in the context in which it is supposed to be used in. A study called "Profile of mecasermin for the long-term treatment of growth failure in children and adolescents with severe primary IGF-1 deficiency" exposes this fact as it reveals that in all the studies in which Increlex has been used, it has not been proven to be effective at causing height growth and can not be used as a substitute to HGH yet, with the efficacy that it's currently showing!
All in all, we've been fooled by the idea of IGF-1 LR3, thinking it would be a possible gateway to faster heightmaxxing gains, but in reality, it's nothing more than a waste of time. However, I could be wrong, we do need to see more people try LR3 and check their serum IGF-1 levels to get more of a definitive idea but it's not looking good so far. IGF-1 Des may have more potential since it's closer to the actual IGF-1 peptide than LR3!
Last edited:
