AX-2025-020899 · MK-677 (Ibutamoren mesylate) · WXT lot WXT-2502-F2050

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	99.59	% area	≥ 98.5	PASS
Total impurities	RP-HPLC, sum of reported peaks	0.41	% area	≤ 1.5	PASS
Largest single impurity	RP-HPLC — sulfonamide hydrolysis product (+18 Da)	0.17	% 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)	624.2190	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	+1.4	ppm	± 10	PASS
Peptide content	not ordered on this submission	not determined	—	required to check label claim	NOT TESTED
Water content	Karl Fischer, coulometric, duplicate	4.78	%	≤ 10.0	PASS
Counter-ion (mesylate)	anion-exchange ion chromatography	13.02	%	≤ 12.0	FAIL
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.42	%	—	NOT TESTED
Endotoxin	kinetic chromogenic LAL	6.58	EU/mg	≤ 5.0	FAIL
Sterility	not ordered on this submission	not determined	—	no growth	NOT TESTED
Appearance	visual, diffuse light, black and white background	Off-white lyophilised cake, intact	—	white to off-white intact cake	PASS
Reconstitution clarity	reconstituted per submitter procedure	Faint haze, clearing on standing	—	clear, no visible particulates	FAIL
pH (reconstituted, 1 mg/mL)	potentiometric, two-point calibration	5.53	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 32 min gradient	14.85	min	14.71 ± 0.30 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.11	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	63,131	—	≥ 20,000	PASS
Resolution to nearest impurity	vs free base (des-mesylate, −96 Da)	0.18	—	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 63,131, and skew follows the reported asymmetry factor of 1.11. 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 0.17 % impurity against a 99.59 % 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	14.85	4,840,383	99.59	—
2	sulfonamide hydrolysis product (+18 Da)	13.93	8,263	0.17	+18.011
3	residual DMF (process solvent)	6.10	7,776	0.16	-551.000
4	O-desmethyl metabolite analogue (−14 Da)	14.30	1,944	0.04	-14.016
5	free base (des-mesylate, −96 Da)	14.89	1,944	0.04	-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, high-resolution instrument. Sticks are placed at m/z = (M + z × 1.007276)/z for the observed neutral mass of 624.2190 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	313.1168	0.0005	52.3
1+	625.2254	625.2263	0.0009	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.

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)	99.82	99.59	divergence +0.21 pp vs batch median
Total impurities (% area)	0.18	0.41
Largest single impurity (% area)	0.11	0.17
Water (%)	2.4	4.78
Counter-ion (%)	not stated	13.02
Peptide content (%w/w)	not stated	not determined
Endotoxin (EU/mg)	not stated	6.58
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, 13 d) → laboratory (courier, cold pack, 6 d) → assay.
Assay date: 26 Feb 2025
Submitted to the index: 13 Mar 2025
Laboratory: VendorInvestigate, Riga, Latvia
Method basis: 32 min gradient · high-resolution MS
Verification status: VERIFIED

What this report does not establish

How much of the named compound is in the vial. Peptide content was not determined, so recovered mass cannot be calculated and the label claim cannot be checked.
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 5

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.

quad_unit13 Mar 2025

The index grades identity by instrument class, not by the ppm figure alone: "confirmed" where the determination was made at high resolution, "consistent with" where it was not. The status block above says which applies to this record, and it is worth reading before the number.

buyer_sourced13 Mar 2025

A retail vial at 99.59 % is worth more evidentially than a selected vial at a higher figure. That is the whole argument for recording provenance at all.

storage_stated13 Mar 2025

Stated storage conditions on the certificate against the observed transit conditions in the custody block: on this record they agree, which removes one class of explanation for anything unexpected.

peak_integrator13 Mar 2025

Resolution to the nearest named impurity is reported on this record with no verdict attached, which is the correct handling. A threshold on that figure would penalise compounds for their own impurity profiles.

baseline_noise13 Mar 2025

Agreed, and nothing further from me.

Section 7

Related records

Same batch — lot WXT-2502-F2050 n=8

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2025-020897	WXT-2502-F2050	Janoshik	2025-Q1	99.20	4.39	91.7	Buyer-sourced	1	FAIL
AX-2025-020898	WXT-2502-F2050	PeptideMeter	2025-Q1	99.64	4.40	—	Buyer-sourced	0	FAIL
AX-2025-020900	WXT-2502-F2050	PeptideMeter	2025-Q1	99.48	4.33	90.2	Buyer-sourced	0	FAIL
AX-2025-020901	WXT-2502-F2050	Janoshik	2025-Q1	99.45	4.41	—	Buyer-sourced	0	FAIL
AX-2025-020902	WXT-2502-F2050	Medutest	2025-Q1	99.72	4.14	106.8	Buyer-sourced	0	FAIL
AX-2025-020903	WXT-2502-F2050	Janoshik	2025-Q1	99.62	4.12	100.8	Buyer-sourced	0	FAIL
AX-2025-020904	WXT-2502-F2050	Janoshik	2025-Q1	99.70	4.69	101.0	Buyer-sourced	0	FAIL

Batch rollup and reproducibility assessment →

Cross-sections

All MK-677 (Ibutamoren mesylate) records n=143
All WXT records n=301
All VendorInvestigate records n=593
All 2025-Q1 records n=672
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 WXT records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043376	Semaglutide	WXT-2604-C3248	Janoshik	2026-Q3	97.08	4.22	—	Buyer-sourced	1	MARGINAL
AX-2026-043429	L-Glutathione (reduced)	WXT-2605-B3833	Nordanalyt	2026-Q3	98.48	6.58	96.9	Supplier-supplied	1	FAIL
AX-2026-043347	Leuprolide	WXT-2604-K2596	PeptideMeter	2026-Q3	99.16	5.99	93.6	Buyer-sourced	0	PASS
AX-2026-043353	Leuprolide	WXT-2604-K2596	Janoshik	2026-Q3	99.19	4.90	95.3	Laboratory-retained	0	PASS
AX-2026-043345	Leuprolide	WXT-2604-K2596	Janoshik	2026-Q3	98.93	5.28	—	Buyer-sourced	0	PASS
AX-2026-043424	L-Glutathione (reduced)	WXT-2605-B3833	PeptideMeter	2026-Q3	98.37	6.86	—	Buyer-sourced	0	FAIL
AX-2026-043374	Semaglutide	WXT-2604-C3248	Janoshik	2026-Q3	97.00	3.56	—	Buyer-sourced	1	MARGINAL
AX-2026-043377	Semaglutide	WXT-2604-C3248	PeptideMeter	2026-Q3	97.20	4.08	—	Buyer-sourced	1	MARGINAL