Sable · Question
What is the difference between Sermorelin and P21?
Sermorelin is the 29-residue N-terminal fragment of growth hormone-releasing hormone, the shortest fully active GHRH fragment, used in GHRH receptor research (peptide, MW about 3357.9 g/mol).
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Last verified 2026-10-10
What is the difference between Sermorelin and P21?
Sermorelin is the 29-residue N-terminal fragment of growth hormone-releasing hormone, the shortest fully active GHRH fragment, used in GHRH receptor research (peptide, MW about 3357.9 g/mol).
Which is heavier, Sermorelin or P21?
Sermorelin has a molecular weight of about 3357.9 g/mol and P21 about 578.7 g/mol (PubChem), so Sermorelin is heavier by 2,779.2 g/mol, a ratio of 5.8. This means 1 mg of Sermorelin contains 297.8 nmol versus 1,728 nmol for P21.
How many mg of P21 are equimolar to 1 mg of Sermorelin?
1 mg of Sermorelin (MW 3357.9) is 297.8 nmol. The same number of moles of P21 (MW 578.7) weighs 0.1723 mg. Equimolar comparisons matter when testing two compounds side by side in the same assay.
Compare the molecular formulas of Sermorelin and P21
PubChem lists Sermorelin as C149H246N44O42S (3357.9 g/mol) and P21 as C27H42N6O8 (578.7 g/mol). Sermorelin is a peptide; P21 is a peptidomimetic. These formulas refer to the parent compounds without salt counter-ions.
A 10 mg vial of P21 equals how many mg of Sermorelin in moles?
10 mg of P21 (MW 578.7) is 17.28 µmol. The same amount of Sermorelin (MW 3357.9) would weigh 58.025 mg. This equimolar conversion lets two compounds be compared at matched molar amounts in the same experiment.
A 5 mg vial of P21 equals how many mg of Sermorelin in moles?
5 mg of P21 (MW 578.7) is 8.64 µmol. The same amount of Sermorelin (MW 3357.9) would weigh 29.012 mg. This equimolar conversion lets two compounds be compared at matched molar amounts in the same experiment.
A 2 mg vial of Sermorelin equals how many mg of P21 in moles?
2 mg of Sermorelin (MW 3357.9) is 0.5956 µmol. The same amount of P21 (MW 578.7) would weigh 0.3447 mg. This equimolar conversion lets two compounds be compared at matched molar amounts in the same experiment.
A 5 mg vial of Sermorelin equals how many mg of P21 in moles?
5 mg of Sermorelin (MW 3357.9) is 1.489 µmol. The same amount of P21 (MW 578.7) would weigh 0.8617 mg. This equimolar conversion lets two compounds be compared at matched molar amounts in the same experiment.
A 10 mg vial of Sermorelin equals how many mg of P21 in moles?
10 mg of Sermorelin (MW 3357.9) is 2.978 µmol. The same amount of P21 (MW 578.7) would weigh 1.723 mg. This equimolar conversion lets two compounds be compared at matched molar amounts in the same experiment.
More questions about sermorelin
A CoA for every lot; each vial carries a printed lot number that matches it. Ask with the lot number and we send it.
Cite this
Research use only. Not for consumption. No health claims.
Plain
Sable Peptides. (2026). What is the difference between Sermorelin and P21?. UK Research Peptide Reference. Retrieved 11 October 2026, from https://www.sablepeptides.co.uk/questions/compare/p21-vs-sermorelin/#sqa-040918
APA
Sable Peptides. (2026, October 11). *What is the difference between Sermorelin and P21?*. UK Research Peptide Reference. https://www.sablepeptides.co.uk/questions/compare/p21-vs-sermorelin/#sqa-040918
BibTeX
@misc{sable_#sqa-040918_2026,
author = {{Sable Peptides}},
title = {{What is the difference between Sermorelin and P21?}},
year = {2026},
howpublished = {\url{https://www.sablepeptides.co.uk/questions/compare/p21-vs-sermorelin/#sqa-040918}},
note = {Accessed 11 October 2026. CC BY 4.0}
}Badge
<a href="https://www.sablepeptides.co.uk/ref"><img src="https://www.sablepeptides.co.uk/badge/ref.svg" alt="Data: UK Research Peptide Reference — Sable Peptides" width="220" height="40"></a>
Date modified: 2026-10-10