Sermorelin Specs: Sequence, MW & CAS
Part of the full Sermorelin guide - a growth hormone-releasing hormone reference compound, identity-verified with a COA on every vial.
In brief
Sermorelin's molecular specification is fully defined in the entry, and each parameter carries structure-function meaning rather than being a bare identifier. The molecule is a 29-amino-acid GHRH analogue with the sequence Tyr-Ala-Asp-Ala-Ile-Phe-Thr-Asn-Ser-Tyr-Arg-Lys-Val-Leu-Gly-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Met-Ser-Arg-NH2 (one-letter YADAIFTNSYRKVLGQLSARKLLQDIMSR-NH2), an average molecular weight of 3357.93 g/mol as the free base, the molecular formula C149H246N44O42S, and CAS Registry Numbers 86168-78-7 for the free base and 114466-38-5 for the acetate salt. This spoke explains what each of these means for a researcher: how the sequence relates to native GHRH, why the C-terminal amidation matters, how the formula and weight underpin quantitative work, and why two CAS numbers exist. Read together, the specs describe a precisely characterized synthetic peptide whose identity and reactivity are traceable to standard chemical registries.
To the molecule
Molecular specifications
Tyr-Ala-Asp-Ala-Ile-Phe-Thr-Asn-Ser-Tyr-Arg-Lys-Val-Leu-Gly-Gln-Leu-Ser-Ala-Arg-Lys-Leu-Leu-Gln-Asp-Ile-Met-Ser-Arg-NH2 (one-letter: YADAIFTNSYRKVLGQLSARKLLQDIMSR-NH2)The detail
A closer look
01
Sequence and its relation to native GHRH
The 29-residue sequence corresponds to residues 1-29 of endogenous human GHRH, and the entry identifies this as the shortest fragment retaining full GHRH biological activity. This is the central structure-function fact: truncating the native 44-residue hormone to its first 29 residues does not sacrifice intrinsic activity at the GHRH receptor. The amino-terminus begins Tyr-Ala (Tyr1-Ala2), the same bond identified as the DPP-IV cleavage site, so the sequence simultaneously encodes both the receptor-active region and the molecule's principal metabolic vulnerability. The presence of multiple basic residues (arginine and lysine) and the overall composition are reflected in the molecular formula. For researchers, the sequence is the definitive identity check and the basis for comparing Sermorelin to full-length GHRH(1-44).
02
C-terminal amidation and potency
The sequence terminates in Arg29-NH2, a carboxy-terminal amidation that the entry states is required for receptor potency. This is a meaningful structural detail rather than a notational flourish: amidation neutralizes the terminal carboxylate and is a common feature of bioactive peptides where it stabilizes the C-terminus and supports high-affinity receptor engagement. Because the data flags the amidation as potency-relevant, any characterization or quality check of a Sermorelin preparation should confirm the amide form rather than the free-acid form. The amidated arginine is also reflected in the molecular formula and average mass, so the 3357.93 g/mol figure corresponds specifically to the amidated, biologically relevant species.
03
Formula, mass, and dual CAS numbers
The molecular formula C149H246N44O42S and average molecular weight of 3357.93 g/mol (free base) are the quantitative anchors for all molar calculations, purity assessment, and mass-spectrometric confirmation. The single sulfur atom corresponds to the methionine residue near the C-terminus. Two CAS Registry Numbers are listed because the molecule exists in distinct salt forms: 86168-78-7 designates the free base, while 114466-38-5 designates the acetate salt, the form in which synthetic peptides are frequently supplied. Distinguishing the two matters for accurate mass accounting, since acetate counterions add to the as-supplied weight. Structural identity, formula, weight, and CAS assignments are corroborated in the entry by references to PubChem CID 16132413 and standard chemical registries.
The fine print: products are sold for laboratory research use only and are not for human or animal consumption. Bodily introduction into humans or animals is strictly prohibited by law. Sermorelin is not a drug and is not intended to diagnose, treat, cure, or prevent any disease. These statements have not been evaluated by the FDA.