Sermorelin Acetate

1 Identity

Synthetic linear 29-residue peptide amide, isolated as an acetate salt. A counter-ion is not a molecular class. The molecular entity is identical to the preceding record: GHRH(1-29) amide, all residues proteinogenic and L-configured, one methionine at 27, one asparagine at 8, no cysteine, no disulfide, no acylation. and under two sellers' own item numbers. CAS 516482-86-3 for the acetate against CAS 86168-78-7 for the free base — the same molecular entity carrying two registry numbers, which is the whole reason two listings exist in the market.

Sequence

The same molecule as the preceding record and not a distinct product: H-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, GHRH(1-29) amide, C149H246N44O42S, isolated as its acetate salt — which is the ordinary supplied form of this peptide and of most peptides in this catalog. The counter-ion is not part of the sequence. It alters net peptide content per unit mass and alters nothing else: not the sequence, not the C-terminal amidation, not the Met27 and Asn8 degradation profile.

Molecular formula

C149H246N44O42S - XC2H4O2 — the exact notation the supplier uses for its acetate article, with the stoichiometry left as X because it is measured, not assumed. A supplier who prints a fixed subscript has asserted something it did not measure.

Average mass

3357.933 Da for the free base (C149H246N44O42S) on the IUPAC 2021 abridged table. The salt has no single average mass: at 1 mol acetate the formula weight is 3417.99 (acetate 1.76 percent w/w), at 2 mol 3478.04 (3.45 percent), at 3 mol 3538.09 (5.09 percent). A certificate that reports one number for 'sermorelin acetate' has assumed an X it did not measure; the seller that actually sells the article declines to assume it.

Monoisotopic mass

3355.81870 Da free base; [M+H]+ 3356.82598. Acetate does not appear on the peptide molecular ion under standard electrospray conditions, so the mass spectra of an acetate lot and a trifluoroacetate lot are indistinguishable; the counter-ion is established by ion chromatography or 19F NMR and never inferred from MS. No monoisotopic mass is quoted for the salt formula unit, because no instrument observes it.

Salt / variant note

The product name is itself the substitution vector, and this same peptide has been listed under two unrelated store categories — one peptide presented to two audiences under two different promises. The records are merged, and naming one listing for its counter-ion implies the remaining records are free base, which they are not. Every confusable from the preceding record applies unchanged, because a counter-ion changes none of them: GHRH(1-29) free acid C149H245N43O43S, 3358.917 avg / 3356.80271 mono, +0.98 Da; Asn8-deamidated sermorelin at the identical +0.98 shift, so intact mass cannot distinguish the two defects and only chromatography plus peptide mapping can; Mod GRF(1-29) C152H252N44O42, 3367.954 avg / 3365.89358 mono, ten daltons heavier, sulfur-free and carrying D-Ala2; CJC-1295 with DAC C165H269N47O46, 3647.250 avg / 3645.01548 mono; Met27 sulfoxide 3373.932 avg / 3371.81361 mono; Met27 sulfone 3389.931 avg / 3387.80853 mono; deletion sequences across 57.05-163.17 Da. The salt-specific arithmetic is small but real and is the confusion this record invites: acetate 1.76 percent, 3.45 percent and 5.09 percent w/w at 1, 2 and 3 mol; trifluoroacetate 3.28 percent and 6.36 percent at 1 and 2 mol. The market fact that justifies recording the salt at all: two reagent sellers both list the article as the acetate while an institutional supplier catalogs the free-base entity, so the same molecule reaches a laboratory under two counter-ion conventions and two CAS numbers, and a purchaser matching on CAS alone will conclude they are different compounds.

2 Class & testing panel

Form

Single article

Testing panel

P1 — panel definition

3 Primary sources & evidence

The index reports the design and provenance of the literature, not a conclusion about effect.

No literature exists on the acetate salt as a distinct article, and none should be expected: a counter-ion is not a subject of clinical investigation. The evidence base is that of the preceding record — the Geref-era open-label study in 110 children with growth-hormone deficiency (PMID 8772599), the approval-era diagnostic work, and a rodent and in-vitro GHRH-analogue literature — and a duplicate citation index page is not built, because two pages of identical references presented as two products inflates the apparent evidential weight of the catalog.

4 Storage & specification

Storage

As the preceding record: lyophilized powder in amber Type I glass under nitrogen, stored at -20 degrees C plus or minus 5 degrees C, desiccated and protected from light, with the same container-closure recovery check for surface adsorption at low concentration. No separate inventory location and no separate lot series exists for this article, and none is opened, because two locations for one material is how two stock balances diverge.

Shelf life

As the preceding record: provisional 24-month retest interval at -20 degrees C plus or minus 5 degrees C, desiccated, pending this company's stability data, with methionine sulfoxide and total deamidated species as the trended attributes that set the date. No second retest interval is created for a salt form of a molecule that already has one.