Survodutide

1 Identity

Synthetic acylated lipopeptide, not a plain peptide: a 29-residue glucagon-backbone analog, C-terminally amidated, carrying one non-proteinogenic residue at position 2 and a fatty-diacid side chain on a lysine epsilon-amine through a Gly/Ser hexapeptide spacer and a gamma-glutamyl unit. The acyl group and its linker are part of the molecule and must appear in any specification. Position 2 is 1-aminocyclobutane-1-carboxylic acid (Ac4c), a quaternary alpha,alpha-disubstituted residue — not aminoisobutyric acid, which is what documents in circulation for this molecule say and which the structure contradicts. The difference is arithmetic rather than cosmetic: it sets the impurity interval for the skipped building block at 26.04 Da and not at the 14.03 Da an Aib description implies. No cysteine, no disulfide, no methionine and therefore no sulfur anywhere in the molecule, which the formula confirms. Developed by Boehringer Ingelheim with Zealand Pharma A/S as originating co-developer. Cataloged by suppliers as a glucagon-receptor / GLP-1-receptor dual agonist; that is recorded as an indexing fact about how the article is listed, not as a statement in this catalog's voice about anything it does in a person. Not to be confused with the incretin articles on the adjacent shelf: semaglutide, tirzepatide, liraglutide and glucagon itself are all arithmetically separable from it and all four are named with their masses below.

Sequence

H-His-{Ac4c}-Gln-Gly-Thr-Phe-Thr-Ser-Asp-Tyr-Ser-Lys-Tyr-Leu-Asp-Glu-Arg-Ala-Ala-Lys-Asp-Phe-Ile-Lys(Gly-Ser-Gly-Ser-Gly-Gly-gammaGlu-C18 diacid)-Trp-Leu-Glu-Ser-Ala-NH2. Twenty-nine residues. Position 2 is 1-aminocyclobutane-1-carboxylic acid. The C-terminus IS amidated. Lys24 carries the acyl side chain: a Gly/Ser hexapeptide spacer, then gamma-glutamate, then an octadecanedioic (C18) diacid. There is no AEEA unit anywhere in the molecule — the oligoethylene-glycol spacer that appears in semaglutide, and in descriptions of this article that have been carried over from it, is simply not present, and an AEEA line on any document for this molecule is a red flag rather than a specification. One caution is carried rather than resolved: the supplier structure writes the spacer Gly-Ser-Gly-Ser-Gly-Gly and an independent reconstruction writes it GGSGSG. The composition is identical (four Gly, two Ser), so formula and mass are unaffected, but the residue order is not settled between sources and is fixed against the originator disclosure before any sequence line is printed on a page.

Molecular formula

C192H289N47O61. No sulfur, no halogen, no phosphorus, no metal. A second formula circulates for this article in a reagent catalog, C181H270N44O59, whose average mass is 4006.400 and whose monoisotopic mass is 4003.94798; those numbers describe some other substance and the formula is a red flag rather than a specification.

Average mass

4231.692 Da (C192H289N47O61), on IUPAC 2021 abridged conventional atomic weights. A reagent catalog publishes 4231.7 for the same formula, which is the same number to the precision that catalog states.

Monoisotopic mass

4229.09570 Da neutral. To be used with a deconvoluted charge envelope, never a single-ion match: at this mass and with six-plus basic centers the practical charge states run [M+4H]4+ 1058.28166, [M+5H]5+ 846.82715 and [M+6H]6+ 705.85756, and a single-ion assignment at any one of them is not identity.

Salt / variant note

One commercial article under this name; no second molecule was found. The variants that matter are the failure modes and the neighbors. Des-acyl backbone C155H228N40O47 3403.762 average / 3401.66805 monoisotopic, so the true des-acylation interval is 827.93 Da average and 827.43 Da monoisotopic — not the 570.7 and 715.9 Da figures that circulate, both of which are wrong and both of which would set an impurity window around empty space. Ac4c-to-Ala substitution, which is what happens when the non-proteinogenic building block is skipped, is 26.04 Da light (Ac4c residue 97.117 against Ala residue 71.079); an Aib-to-Ala figure of 14.03 Da describes a residue this molecule does not contain. Ac4c-to-Aib is 12.01 Da light. The positional isomer carries no mass difference at all: acylation on Lys12 or Lys20 instead of Lys24 is exactly isobaric with parent at 4231.692 and is undetectable by mass at any resolving power, so it is a chromatographic control or it is not controlled. Free octadecanedioic acid C18H34O4 314.466 / 314.24571 as a process residue. Bis-acylated material sits one full side-chain heavier. Deletion peptides span 57.05 Da (Gly) to 186.21 Da (Trp) below parent. The substitution risk in this channel is the cheap incretin on the next shelf and all four are arithmetically separable: semaglutide C187H291N45O59 4113.641 / 4111.11538; tirzepatide C225H348N48O68 4813.527 / 4810.52486; liraglutide C172H265N43O51 3751.262 / 3748.94646; glucagon C153H225N43O49S 3482.795 / 3480.61570 — and glucagon is the only one of the five carrying sulfur, which settles it in one spectrum.

2 Class & testing panel

Form

Single article

Testing panel

P2 — panel definition

3 Primary sources & evidence

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

Substantial and sponsor-run. Peer-reviewed Phase 2: le Roux et al., Lancet Diabetes Endocrinol 2024, obesity dose-finding, PMID 38330987, with a sex and baseline-BMI subgroup analysis in 387 participants at Diabetes Obes Metab 2025, PMID 39821928; Sanyal et al., NEJM 2024, MASH with fibrosis, PMID 38847460, the strongest peer-reviewed item and the basis of the Breakthrough designation; Bluher et al., Diabetologia 2024, type 2 diabetes with an active comparator, PMID 38095657. Phase 3 design and baseline publications: Wharton et al., Obesity 2025, PMID 39495965, and Wharton et al., Diabetes Obes Metab 2026, PMID 41216778. Registered program verified on ClinicalTrials.gov: NCT04667377 (Ph2, n=387), NCT04771273 (Ph2, n=295), NCT06066515 SYNCHRONIZE-1 (Ph3, n=726, completed), NCT06066528 (Ph3, n=755, completed), NCT06077864 SYNCHRONIZE-CVOT (Ph3, n=5,531, completed), NCT06309992 SYNCHRONIZE-MASLD (Ph3, n=218, completed), NCT06632444 LIVERAGE (Ph3, n=1,800, recruiting), NCT06632457 LIVERAGE-Cirrhosis (Ph3, n=1,590, recruiting), NCT06176365 (Japan, n=274), NCT06214741 (China, n=307), NCT05202353 (Ph1), NCT06200467 (cardiac safety). What is company topline and not peer-reviewed, stated as such: the SYNCHRONIZE-1 result reported in a Boehringer Ingelheim release of 28 April 2026, and the accompanying body-composition characterization, neither of which has appeared in the peer-reviewed literature. Absences: no regulatory approval anywhere; no United States submission has been announced; no published SYNCHRONIZE-CVOT result was identified; no independent non-sponsor trial; no survodutide-specific carcinogenicity assessment was identified; immunogenicity is not characterized in the literature identified.

4 Storage & specification

Storage

Stored as the lyophilized solid at -20 degrees C plus or minus 5 degrees C, desiccated and protected from light, in amber glass with the headspace displaced and a tamper-evident closure. Acylated peptides of this class are aggregation-prone in solution and reconstituted material is treated as single-use with a measured recovery check on the actual vial and stopper rather than an assumption carried from another product. A supplier datasheet records lyophilized powder at -20 degrees C, purity not less than 98 percent, solubility in PBS pH 7.2 at not less than 10 mg/mL, protect from moisture, avoid repeated freeze-thaw; that is a supplier statement and not this company's specification.

Shelf life

Provisional 24 months at -20 degrees C plus or minus 5 degrees C for an acylated 29-mer of this type, with high-molecular-weight species and des-acyl content trended by name as the two governing attributes. Each lot is dated from its date of manufacture and carries that retest date on its certificate, and the interval is confirmed against the company's own stability data as that data accrues.