AX-2026-043486 · MK-677 (Ibutamoren mesylate) · BCH lot BCH-2601-G4997

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, 15 min gradient, 214 nm	97.90	% area	≥ 98.5	FAIL
Total impurities	RP-HPLC, sum of reported peaks	2.10	% area	≤ 1.5	FAIL
Largest single impurity	RP-HPLC — spiroindane regioisomer	1.02	% area	≤ 1.00	FAIL
Identity — theoretical monoisotopic mass	calculated from molecular formula	624.2181	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, unit resolution (single quadrupole)	624.2300	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	+19.1	ppm	± 10	FAIL
Total peptide content	by difference from the gravimetric mass balance	82.26	%w/w	—	NOT TESTED
Target-compound content	total peptide content × purity	80.53	%w/w	—	NOT TESTED
Gross fill (as weighed)	five-place balance, under nitrogen	622.52	mg	500 mg declared	NOT TESTED
Recovered target peptide	gross fill × target content	501.315	mg	500 mg claim	NOT TESTED
Recovery against label claim	recovered ÷ claim	100.3	%	90.0 – 110.0	PASS
Water content	Karl Fischer, coulometric, duplicate	3.62	%	≤ 10.0	PASS
Counter-ion (mesylate)	anion-exchange ion chromatography	13.91	%	≤ 12.0	FAIL
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.21	%	—	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 after 90 s gentle swirling, no particulates	—	clear, no visible particulates	PASS
pH (reconstituted, 1 mg/mL)	potentiometric, two-point calibration	4.96	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 15 min gradient	7.51	min	7.48 ± 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	72,017	—	≥ 20,000	PASS
Resolution to nearest impurity	vs free base (des-mesylate, −96 Da)	0.17	—	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, 15 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 72,017, 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 1.02 % impurity against a 97.90 % 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	7.51	4,758,243	97.90	—
2	spiroindane regioisomer	7.73	49,575	1.02	0.000
3	sulfonamide hydrolysis product (+18 Da)	7.08	29,162	0.60	+18.011
4	O-desmethyl metabolite analogue (−14 Da)	7.25	14,095	0.29	-14.016
5	residual DMF (process solvent)	3.41	5,832	0.12	-551.000
6	free base (des-mesylate, −96 Da)	7.53	3,402	0.07	-96.011
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, unit-resolution instrument. Sticks are placed at m/z = (M + z × 1.007276)/z for the observed neutral mass of 624.2300 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	313.1223	0.0060	56.5
1+	625.2254	625.2373	0.0119	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	3.62
Counter-ion (mesylate)	ion chromatography	13.91
Residual solvent + inorganic residue	estimated	0.21
Total peptide content	by difference	82.26
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)	98.38	97.90	divergence +0.48 pp vs batch median
Total impurities (% area)	1.62	2.10
Largest single impurity (% area)	0.81	1.02
Water (%)	not stated	3.62
Counter-ion (%)	8.2	13.91
Peptide content (%w/w)	87.7	82.26
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: Laboratory-retained
Evidentiary weight: Provenance documented, selection uncontrolled.
Chain of custody: Laboratory retained sample (−20 °C, 29 d since original receipt) → re-assay.
Assay date: 12 Mar 2026
Submitted to the index: 28 Mar 2026
Laboratory: Kestrel Bioanalytical, Melbourne, Australia
Method basis: 15 min gradient · unit-resolution MS
Verification status: IDENTITY CONSISTENT

What this report does not establish

That the compound is not a near-isobaric alternative. Identity was confirmed at unit mass resolution, which cannot exclude species differing by 1 or 2 Da. The specific alternatives not excluded are named in the identity block above.
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.

gradient_2528 Mar 2026

Before treating 97.90 % as a process finding, check what it is being compared against. The index specification assumes the reference gradient; a figure taken on a different method is not automatically comparable to it.

endotoxin_limit28 Mar 2026

Endotoxin is a fill-suite property, so it is broadly consistent within a supplier and within a period. That consistency is what makes the gap worth closing on a sample of lots rather than on all of them.

thin_coverage28 Mar 2026

The index would rather this page said nothing about endotoxin than said something unsupported. That is the standing editorial position and it is applied uniformly.

fill_homogeneity28 Mar 2026

A single vial is a single draw from a fill. Within-lot variation in this index has a median of 0.28 pp, so a second result would usually land close — but usually is not a finding.

Section 7

Related records

Same batch — lot BCH-2601-G4997 n=1

This is the only report on this lot. One report is not a batch characterisation.

Batch rollup and reproducibility assessment →

Cross-sections

All MK-677 (Ibutamoren mesylate) records n=143
All BCH records n=209
All Kestrel records n=407
All 2026-Q1 records n=806
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 BCH records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043445	BPC-157	BCH-2603-G4350	Nordanalyt	2026-Q3	98.42	4.87	93.6	Buyer-sourced	1	MARGINAL
AX-2026-043440	BPC-157	BCH-2603-G4350	VendorInvestigate	2026-Q3	98.61	4.11	—	Buyer-sourced	1	MARGINAL
AX-2026-043442	BPC-157	BCH-2603-G4350	Janoshik	2026-Q3	98.65	4.78	—	Buyer-sourced	1	MARGINAL
AX-2026-043471	CJC-1295 with DAC	BCH-2607-H5235	Janoshik	2026-Q3	97.46	5.48	—	Buyer-sourced	1	FAIL
AX-2026-043477	CJC-1295 with DAC	BCH-2607-H5235	VendorInvestigate	2026-Q3	97.62	5.32	99.6	Buyer-sourced	1	MARGINAL
AX-2026-043449	BPC-157	BCH-2603-G4350	Kestrel	2026-Q3	99.74	4.92	91.3	Supplier-supplied	2	MARGINAL
AX-2026-043448	BPC-157	BCH-2603-G4350	Janoshik	2026-Q3	98.55	4.69	106.9	Buyer-sourced	1	MARGINAL
AX-2026-043470	CJC-1295 with DAC	BCH-2607-H5235	Janoshik	2026-Q3	97.76	6.11	99.3	Supplier-supplied	1	MARGINAL