AX-2026-042920 · MK-677 (Ibutamoren mesylate) · MKM lot MKM-2509-T2950

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	98.42	% area	≥ 98.5	FAIL
Total impurities	RP-HPLC, sum of reported peaks	1.58	% area	≤ 1.5	FAIL
Largest single impurity	RP-HPLC — sulfonamide hydrolysis product (+18 Da)	1.07	% area	≤ 1.00	FAIL
Identity — theoretical monoisotopic mass	calculated from molecular formula	624.2181	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, high resolution (ESI-TOF/QTOF)	624.2180	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	-0.1	ppm	± 10	PASS
Total peptide content	by difference from the gravimetric mass balance	82.48	%w/w	—	NOT TESTED
Target-compound content	total peptide content × purity	81.18	%w/w	—	NOT TESTED
Gross fill (as weighed)	five-place balance, under nitrogen	1113.34	mg	1000 mg declared	NOT TESTED
Recovered target peptide	gross fill × target content	903.809	mg	1000 mg claim	NOT TESTED
Recovery against label claim	recovered ÷ claim	90.4	%	90.0 – 110.0	PASS
Water content	Karl Fischer, coulometric, duplicate	3.29	%	≤ 10.0	PASS
Counter-ion (mesylate)	anion-exchange ion chromatography	13.93	%	≤ 12.0	FAIL
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.30	%	—	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	Off-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	4.60	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 32 min gradient	14.77	min	14.71 ± 0.30 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	0.92	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	72,857	—	≥ 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 72,857, and skew follows the reported asymmetry factor of 0.92. 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 1.07 % impurity against a 98.42 % 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	14.77	4,783,517	98.42	—
2	sulfonamide hydrolysis product (+18 Da)	13.85	52,005	1.07	+18.011
3	free base (des-mesylate, −96 Da)	14.81	11,665	0.24	-96.011
4	spiroindane regioisomer	15.24	6,804	0.14	0.000
5	O-desmethyl metabolite analogue (−14 Da)	14.22	3,402	0.07	-14.016
6	residual DMF (process solvent)	6.02	2,916	0.06	-551.000
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 624.2180 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	313.1163	-0.0000	58.0
1+	625.2254	625.2253	-0.0001	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	3.29
Counter-ion (mesylate)	ion chromatography	13.93
Residual solvent + inorganic residue	estimated	0.30
Total peptide content	by difference	82.48
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)	99.38	98.42	divergence +0.96 pp vs batch median
Total impurities (% area)	0.62	1.58
Largest single impurity (% area)	0.34	1.07
Water (%)	2.6	3.29
Counter-ion (%)	3.9	13.93
Peptide content (%w/w)	92.9	82.48
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, 9 d) → laboratory (hand-carried, 8 d) → assay.
Assay date: 18 Feb 2026
Submitted to the index: 26 Feb 2026
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

No annotations on this record. Annotations are short signed technical comments from index contributors; see how to contribute.

Section 7

Related records

Same batch — lot MKM-2509-T2950 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=152
All MKM records n=272
All VendorInvestigate records n=601
All 2026-Q1 records n=832
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-2026-043524	BCH	BCH-2511-G7276	Janoshik	2026-Q2	98.36	4.68	—	Supplier-supplied	1	FAIL
AX-2026-041764	FGP	FGP-2604-K1470	Janoshik	2026-Q2	99.93	5.34	—	Supplier-supplied	1	FAIL
AX-2026-043527	BCH	BCH-2511-G7276	Janoshik	2026-Q2	98.35	4.36	95.5	Supplier-supplied	1	FAIL
AX-2026-042409	SWB	SWB-2605-B4738	Medutest	2026-Q2	99.32	2.99	94.9	Laboratory-retained	1	FAIL
AX-2026-043526	BCH	BCH-2511-G7276	Medutest	2026-Q2	97.60	4.50	—	Buyer-sourced	1	FAIL
AX-2026-042410	SWB	SWB-2605-B4738	Janoshik	2026-Q2	99.61	2.81	—	Supplier-supplied	1	FAIL
AX-2026-041765	FGP	FGP-2604-K1470	Janoshik	2026-Q2	99.93	5.08	—	Supplier-supplied	0	FAIL
AX-2026-043525	BCH	BCH-2511-G7276	Medutest	2026-Q2	98.37	4.32	—	Buyer-sourced	1	FAIL

Other recent MKM records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-042943	Adipotide	MKM-2606-K4013	Janoshik	2026-Q3	97.92	6.31	—	Supplier-supplied	1	MARGINAL
AX-2026-042891	CJC-1295 (no DAC)	MKM-2603-V2347	Janoshik	2026-Q3	99.28	3.63	—	Supplier-supplied	1	MARGINAL
AX-2026-042942	Adipotide	MKM-2606-K4013	VendorInvestigate	2026-Q3	97.04	5.56	94.6	Buyer-sourced	1	FAIL
AX-2026-042914	Gonadorelin	MKM-2604-A2596	Janoshik	2026-Q2	99.93	5.19	—	Supplier-supplied	0	PASS
AX-2026-042884	BPC-157	MKM-2605-X2575	Nordanalyt	2026-Q2	98.12	2.89	—	Laboratory-retained	1	MARGINAL
AX-2026-042946	Tirzepatide	MKM-2601-L3752	Medutest	2026-Q2	97.71	8.10	—	Supplier-supplied	1	FAIL
AX-2026-042911	Gonadorelin	MKM-2604-A2596	Medutest	2026-Q2	99.08	5.55	—	Buyer-sourced	1	MARGINAL
AX-2026-042932	L-Glutathione (reduced)	MKM-2511-F2902	Janoshik	2026-Q2	98.57	8.41	92.9	Supplier-supplied	1	MARGINAL