AX-2024-005248 · MK-677 (Ibutamoren mesylate) · WXT lot WXT-2408-P3767

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, 30 min gradient, 214 nm	98.91	% area	≥ 98.5	PASS
Total impurities	RP-HPLC, sum of reported peaks	1.09	% area	≤ 1.5	PASS
Largest single impurity	RP-HPLC — sulfonamide hydrolysis product (+18 Da)	0.61	% 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)	624.2205	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	+3.9	ppm	± 10	PASS
Total peptide content	by difference from the gravimetric mass balance	79.10	%w/w	—	NOT TESTED
Target-compound content	total peptide content × purity	78.24	%w/w	—	NOT TESTED
Gross fill (as weighed)	five-place balance, under nitrogen	1343.45	mg	1000 mg declared	NOT TESTED
Recovered target peptide	gross fill × target content	1051.115	mg	1000 mg claim	NOT TESTED
Recovery against label claim	recovered ÷ claim	105.1	%	90.0 – 110.0	PASS
Water content	Karl Fischer, coulometric, duplicate	4.81	%	≤ 10.0	PASS
Counter-ion (mesylate)	anion-exchange ion chromatography	15.68	%	≤ 12.0	FAIL
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.41	%	—	NOT TESTED
Endotoxin	kinetic chromogenic LAL	0.39	EU/mg	≤ 5.0	PASS
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 with a single visible fibre	—	clear, no visible particulates	FAIL
pH (reconstituted, 1 mg/mL)	potentiometric, two-point calibration	5.22	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 30 min gradient	13.82	min	13.86 ± 0.30 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.06	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	53,032	—	≥ 20,000	PASS
Resolution to nearest impurity	vs free base (des-mesylate, −96 Da)	0.16	—	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, 30 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 53,032, and skew follows the reported asymmetry factor of 1.06. 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 0.61 % impurity against a 98.91 % 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	13.82	4,807,333	98.91	—
2	sulfonamide hydrolysis product (+18 Da)	12.96	29,648	0.61	+18.011
3	free base (des-mesylate, −96 Da)	13.86	11,665	0.24	-96.011
4	spiroindane regioisomer	14.26	4,860	0.10	0.000
5	residual DMF (process solvent)	5.62	3,888	0.08	-551.000
6	O-desmethyl metabolite analogue (−14 Da)	13.30	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 624.2205 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	313.1175	0.0012	56.9
1+	625.2254	625.2278	0.0024	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	4.81
Counter-ion (mesylate)	ion chromatography	15.68
Residual solvent + inorganic residue	estimated	0.41
Total peptide content	by difference	79.10
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)	99.0	98.91	divergence -0.10 pp vs batch median
Total impurities (% area)	1.00	1.09
Largest single impurity (% area)	not stated	0.61
Water (%)	not stated	4.81
Counter-ion (%)	9.0	15.68
Peptide content (%w/w)	86.9	79.10
Endotoxin (EU/mg)	not stated	0.39
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 (−20 °C, 20 d) → laboratory (courier, dry ice, 11 d) → assay.
Assay date: 13 Nov 2024
Submitted to the index: 24 Nov 2024
Laboratory: Janoshik Analytical, Ostrava, Czechia
Method basis: 30 min gradient · high-resolution MS
Verification status: VERIFIED

What this report does not establish

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.

charge_envelope24 Nov 2024

Identity confirmed, purity 98.91 %, mass balance closed. This record is complete against the index definition of complete and there is nothing outstanding on it.

coa_template24 Nov 2024

Nothing on this record contradicts the declaration. Purity 98.91 %, largest single impurity sulfonamide hydrolysis product (+18 Da) at 0.61 %, mass balance closed.

buyer_sourced24 Nov 2024

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

peak_integrator24 Nov 2024

Two laboratories with different gradients will resolve a close pair differently and report two honest, different purities. Neither is wrong and the difference is not a disagreement about the material.

Section 7

Related records

Same batch — lot WXT-2408-P3767 n=9

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2025-021003	WXT-2408-P3767	PeptideMeter	2024-Q4	99.12	4.55	—	Buyer-sourced	1	FAIL
AX-2024-005243	WXT-2408-P3767	Nordanalyt	2024-Q4	99.11	4.94	94.4	Buyer-sourced	1	FAIL
AX-2024-005244	WXT-2408-P3767	Janoshik	2024-Q4	98.70	4.57	102.8	Buyer-sourced	2	FAIL
AX-2024-005245	WXT-2408-P3767	Kestrel	2024-Q4	98.73	4.83	92.4	Buyer-sourced	1	FAIL
AX-2024-005246	WXT-2408-P3767	Medutest	2024-Q4	99.29	4.65	89.7	Buyer-sourced	2	FAIL
AX-2024-005247	WXT-2408-P3767	Kestrel	2024-Q4	99.09	4.42	—	Buyer-sourced	2	FAIL
AX-2024-005249	WXT-2408-P3767	Janoshik	2024-Q4	99.35	4.50	104.3	Buyer-sourced	1	FAIL
AX-2025-021004	WXT-2408-P3767	Janoshik	2024-Q4	99.10	4.92	91.6	Supplier-supplied	1	FAIL

Batch rollup and reproducibility assessment →

Cross-sections

All MK-677 (Ibutamoren mesylate) records n=143
All WXT records n=301
All Janoshik records n=2989
All 2024-Q4 records n=416
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