AX-2024-005362 · MK-677 (Ibutamoren mesylate) · SIG lot SIG-2404-6898

Section 1

Results

Measured against the index acceptance specification for the non-peptide adjuncts class. A specification is a decision the index made; a result is a measurement. See where each threshold came from.

Parameter	Method	Result	Unit	Index spec
Purity	RP-HPLC, 32 min gradient, 214 nm	99.00	% area	≥ 98.5	PASS
Total impurities	RP-HPLC, sum of reported peaks	1.00	% area	≤ 1.5	PASS
Largest single impurity	RP-HPLC — sulfonamide hydrolysis product (+18 Da)	0.57	% area	≤ 1.00	PASS
Identity — theoretical monoisotopic mass	calculated from molecular formula	624.2181	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, high resolution (ESI-TOF/QTOF)	624.2474	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	+46.9	ppm	± 10	FAIL
Total peptide content	by difference from the gravimetric mass balance	81.64	%w/w	—	NOT TESTED
Target-compound content	total peptide content × purity	80.82	%w/w	—	NOT TESTED
Gross fill (as weighed)	five-place balance, under nitrogen	300.52	mg	250 mg declared	NOT TESTED
Recovered target peptide	gross fill × target content	242.880	mg	250 mg claim	NOT TESTED
Recovery against label claim	recovered ÷ claim	97.2	%	90.0 – 110.0	PASS
Water content	Karl Fischer, coulometric, duplicate	3.87	%	≤ 10.0	PASS
Counter-ion (mesylate)	anion-exchange ion chromatography	13.71	%	≤ 12.0	FAIL
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.78	%	—	NOT TESTED
Endotoxin	not ordered on this submission	not determined	—	≤ 5.0	NOT TESTED
Sterility	not ordered on this submission	not determined	—	no growth	NOT TESTED
Appearance	visual, diffuse light, black and white background	White lyophilised cake, intact	—	white to off-white intact cake	PASS
Reconstitution clarity	reconstituted per submitter procedure	Clear, colourless, no visible particulates	—	clear, no visible particulates	PASS
pH (reconstituted, 1 mg/mL)	potentiometric, two-point calibration	5.18	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 32 min gradient	14.66	min	14.71 ± 0.30 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	0.86	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	68,941	—	≥ 20,000	PASS
Resolution to nearest impurity	vs free base (des-mesylate, −96 Da)	0.19	—	no index criterion	REPORTED

Section 2

Chromatogram and peak integration

The figure is drawn from the table. It is not an independent illustration — if a number in the table changed, the trace would change with it.

Figure 1. RP-HPLC trace, 32 min gradient, 214 nm. Drawn from the peak-integration table below: peak positions are the reported retention times, peak areas are the reported area percentages, peak widths follow the reported plate count of 68,941, and skew follows the reported asymmetry factor of 0.86. Baseline noise is seeded from the report ID and is illustrative. The lower panel is the same trace at a stated vertical expansion with the slow gradient drift subtracted, because at full scale a 0.57 % impurity against a 99.00 % main peak is a line two pixels tall; the main peak runs off-scale there by design.

#	Peak	RT	Area (µV·s)	% area	Δ mass (Da)
1	MK-677 (Ibutamoren mesylate) — main peak	14.66	4,811,707	99.00	—
2	sulfonamide hydrolysis product (+18 Da)	13.74	27,704	0.57	+18.011
3	spiroindane regioisomer	15.13	9,721	0.20	0.000
4	residual DMF (process solvent)	5.91	4,860	0.10	-551.000
5	free base (des-mesylate, −96 Da)	14.70	3,402	0.07	-96.011
6	O-desmethyl metabolite analogue (−14 Da)	14.11	2,916	0.06	-14.016
Closure check — purity + Σ impurities				100.00	CLOSES

Reporting threshold 0.05 % area. Peaks below it are not reported and are therefore excluded from the total, which overstates purity by their sum — see peak integration.

Section 3

Mass spectrum and identity

Theoretical monoisotopic mass 624.2181 Da, computed from C27H36N4O5S · CH4O3S. All ppm figures on this site are against monoisotopic values — see why that matters.

Figure 2. ESI charge-state envelope, high-resolution instrument. Sticks are placed at m/z = (M + z × 1.007276)/z for the observed neutral mass of 624.2474 Da. Sodium (+21.982/z) and potassium (+37.956/z) adducts are shown where the parent charge state exceeds 25 % relative abundance; they are adducts of the same molecule and are not impurities.

Charge	Theoretical m/z	Observed m/z	Δ m/z	Rel. abundance (%)
2+	313.1163	313.1310	0.0147	56.8
1+	625.2254	625.2547	0.0293	100.0

Section 4

Gravimetric mass balance

Water, counter-ion, residual and total peptide content are exhaustive and mutually exclusive categories. They must account for 100 % of the cake mass. The index closes this to within 0.02 pp and the build asserts it.

Component	Determination	%w/w of cake
Water	Karl Fischer	3.87
Counter-ion (mesylate)	ion chromatography	13.71
Residual solvent + inorganic residue	estimated	0.78
Total peptide content	by difference	81.64
Total		100.00 CLOSES

Supplier certificate, as declared

The supplier's own figures for this lot, beside the independent measurement. Divergence is assessed against the batch median, not against this single report — see rule AX-R05.

Figure	Supplier COA	This report	Index note
Purity (% area)	98.43	99.00	divergence -0.40 pp vs batch median
Total impurities (% area)	not stated	1.00
Largest single impurity (% area)	not stated	0.57
Water (%)	3.1	3.87
Counter-ion (%)	not stated	13.71
Peptide content (%w/w)	not stated	81.64
Endotoxin (EU/mg)	not stated	not determined
Method stated on certificate	YES	—	column, gradient and wavelength given

Section 5

Provenance and caveats

Where a sample came from changes the weight of the evidence. The index treats it as a first-class field.

Sample provenance: Buyer-sourced
Evidentiary weight: Strongest available evidence in this index.
Chain of custody: Retail purchase → submitter (ambient, 6 d) → laboratory (hand-carried, 8 d) → assay.
Assay date: 05 Sep 2024
Submitted to the index: 24 Sep 2024
Laboratory: VendorInvestigate, Riga, Latvia
Method basis: 32 min gradient · high-resolution MS
Verification status: VERIFIED

What this report does not establish

That the material is free of bacterial endotoxin. Endotoxin was not measured. No chromatographic result bears on it.
That the material is sterile. Sterility was not tested.
That any other vial in the same lot has the same composition. One vial was tested. Within-lot vial-to-vial variation in this index has a median of 0.28 pp and a 90th percentile of 0.74 pp.
That any other lot from the same supplier has the same composition. Batch-to-batch variation is larger than within-batch variation for every supplier here.
That the material is suitable for administration to a human or an animal. These are research compounds. No result on this site is a safety assessment and the index takes no position on use.
That the material was manufactured by the supplier that sold it. Contract synthesis is normal in this market and twenty-nine batches in the index fingerprint to a bulk from a different company than the one named on the label.

Section 6

Annotations 4

Signed technical comments from index contributors. Not a discussion forum — annotations question or contextualise the result, and the data team replies where a reply is warranted.

esi_tof24 Sep 2024

Ion suppression from a co-eluting counter-ion at 13.71 % mesylate can shift an apparent mass in a time-of-flight measurement. Desalting the injection before the mass determination removes the possibility.

buyer_sourced24 Sep 2024

Independently purchased, at the submitter's own cost, forwarded without the supplier's involvement. That is the definition and this record meets it.

selection_bias24 Sep 2024

Provenance handles supplier selection. It does not handle submitter selection, which is the larger confounder and the one the index cannot measure.

bland_altman24 Sep 2024

Where two laboratories tested the same retail lot, the paired difference is a clean estimate of inter-lab bias with no selection term in it at all. Those pairs are the backbone of the agreement analysis.

Section 7

Related records

Same batch — lot SIG-2404-6898 n=9

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Result
AX-2024-005354	SIG-2404-6898	PeptideMeter	2024-Q3	98.86	3.81	99.1	Buyer-sourced	FAIL
AX-2024-005355	SIG-2404-6898	Janoshik	2024-Q3	98.82	3.54	—	Buyer-sourced	FAIL
AX-2024-005356	SIG-2404-6898	PeptideMeter	2024-Q3	98.74	3.36	—	Buyer-sourced	FAIL
AX-2024-005357	SIG-2404-6898	Janoshik	2024-Q3	99.09	3.36	91.8	Laboratory-retained	FAIL
AX-2024-005358	SIG-2404-6898	Janoshik	2024-Q3	98.93	3.02	104.7	Buyer-sourced	FAIL
AX-2024-005359	SIG-2404-6898	Medutest	2024-Q3	98.83	3.00	—	Buyer-sourced	FAIL
AX-2024-005360	SIG-2404-6898	Janoshik	2024-Q3	98.83	4.03	90.3	Buyer-sourced	FAIL
AX-2024-005361	SIG-2404-6898	Janoshik	2024-Q3	98.38	3.18	90.4	Buyer-sourced	FAIL

Batch rollup and reproducibility assessment →

Cross-sections

All MK-677 (Ibutamoren mesylate) records n=143
All SIG records n=160
All VendorInvestigate records n=593
All 2024-Q3 records n=464
MK-677 (Ibutamoren mesylate) by supplier
MK-677 (Ibutamoren mesylate) impurity profile

Other recent MK-677 (Ibutamoren mesylate) records in the index.
Report	Supplier	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-041633	FGP	FGP-2604-K8509	PeptideMeter	2026-Q2	99.81	4.91	96.2	Buyer-sourced	0	FAIL
AX-2026-041733	TFS	TFS-{CAT}-1096	PeptideMeter	2026-Q2	99.07	3.93	95.1	Laboratory-retained	0	FAIL
AX-2026-043468	BCH	BCH-2511-G5204	Medutest	2026-Q2	98.85	4.30	96.5	Buyer-sourced	1	FAIL
AX-2026-042647	SWB	SWB-2605-B7365	Nordanalyt	2026-Q2	99.28	2.86	93.1	Buyer-sourced	0	FAIL
AX-2026-041634	FGP	FGP-2604-K8509	PeptideMeter	2026-Q2	99.86	5.17	—	Buyer-sourced	0	FAIL
AX-2026-043469	BCH	BCH-2511-G5204	Medutest	2026-Q2	98.51	4.86	—	Buyer-sourced	1	FAIL
AX-2026-042648	SWB	SWB-2605-B7365	Janoshik	2026-Q2	99.93	2.60	96.9	Supplier-supplied	0	FAIL
AX-2026-041732	TFS	TFS-{CAT}-1096	Janoshik	2026-Q2	99.48	3.16	106.4	Buyer-sourced	0	FAIL

Other recent SIG records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043535	GHRP-2	SIG-2603-6031	Janoshik	2026-Q3	99.12	1.26	105.7	Buyer-sourced	0	PASS
AX-2026-043541	GHRP-2	SIG-2603-6031	PeptideMeter	2026-Q3	99.06	2.08	107.4	Buyer-sourced	1	MARGINAL
AX-2026-043539	GHRP-2	SIG-2603-6031	Janoshik	2026-Q3	98.95	1.74	100.4	Buyer-sourced	1	FAIL
AX-2026-043534	GHRP-2	SIG-2603-6031	Medutest	2026-Q3	99.11	2.15	89.8	Buyer-sourced	1	MARGINAL
AX-2026-043542	GHRP-2	SIG-2603-6031	VendorInvestigate	2026-Q3	99.05	1.43	—	Buyer-sourced	1	FAIL
AX-2026-043543	GHRP-2	SIG-2603-6031	Janoshik	2026-Q3	99.38	1.70	98.6	Buyer-sourced	0	PASS
AX-2026-043544	GHRP-2	SIG-2603-6031	PeptideMeter	2026-Q3	99.57	1.51	105.4	Buyer-sourced	0	PASS
AX-2026-043538	GHRP-2	SIG-2603-6031	Kestrel	2026-Q3	98.93	1.72	—	Buyer-sourced	0	FAIL