Research Comparison
IGF-1 LR3 vs Sermorelin
A side-by-side research comparison of IGF-1 LR3 and Sermorelin drawn from DRPSHP' peptide database records.
IGF-1 LR3
IGF-1 LR3 is insulin-like growth factor 1 altered in two ways, and the name is a record of both: L for the long N-terminal extension of 13 amino acids added to native IGF-1's 70, giving 83 residues in total, and R3 for arginine replacing glutamate at position 3. Together these changes reduce its affinity for the IGF-binding proteins that normally hold most IGF-1 in bound complexes. It is made by recombinant methods and is best known as a supplement in serum-free media for growing mammalian cell lines. Beyond cell culture the published work is chiefly animal studies, with very limited human data.
Sermorelin
Sermorelin is a synthetic peptide of 29 amino acids that reproduces the front end of human growth hormone-releasing hormone (GHRH). The natural hormone has 44 residues, and the 1-29 segment, with an amidated C-terminus as here, is reported to keep the receptor activity of the whole. Like the hormone itself it is cut rapidly by plasma enzymes including dipeptidyl peptidase-4, a vulnerability that later analogues such as tesamorelin were modified to avoid. Research has centred on growth hormone release from the anterior pituitary, including human physiology studies, many decades old, together with animal and cell work. Recent literature on sermorelin itself is sparse beside that for newer GHRH analogues.
Reading a comparison
A comparison places two records side by side; it does not merge them. Each description above is drawn from that compound's own record, and the two were not necessarily characterised by the same methods, at the same time, or to the same level of detail. Before comparing any attribute, it is worth establishing that both records describe the substance you think they describe — names are not identifiers, and two entries sharing a name can differ in salt form, stereochemistry or the convention used to state a mass. Where a figure carries no method beside it, the comparison is between two reported numbers rather than between two measurements.