AX-2026-042111

MK-677 (Ibutamoren mesylate) · 250 mg declared · Tianjin Finder Chemical Co., Ltd. · lot TFC-2601-L7836

FAILIDENTITY CONSISTENT

Report ID: AX-2026-042111
Compound: MK-677 (Ibutamoren mesylate)
Compound class: Non-peptide adjuncts
Supplier: TFC — Tianjin Finder Chemical Co., Ltd.
Batch / lot: TFC-2601-L7836
Declared label claim: 250mg
Laboratory: Kestrel Bioanalytical
Assay date: 14 Feb 2026
Submitted: 20 Feb 2026
Quarter: 2026-Q1
Submitter: d.guerrero
Sample provenance: Supplier-supplied

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	99.93	% area	≥ 98.5	PASS
Total impurities	RP-HPLC, sum of reported peaks	0.07	% area	≤ 1.5	PASS
Largest single impurity	RP-HPLC — sulfonamide hydrolysis product (+18 Da)	0.04	% area	≤ 1.00	PASS
Identity — theoretical monoisotopic mass	calculated from molecular formula	624.2181	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, unit resolution (single quadrupole)	624.2148	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	-5.3	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	6.38	%	≤ 10.0	PASS
Counter-ion (mesylate)	anion-exchange ion chromatography	16.29	%	≤ 12.0	FAIL
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.25	%	—	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 powder, no defined cake (melt-back)	—	white to off-white intact cake	FAIL
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	5.15	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 15 min gradient	7.58	min	7.48 ± 0.30 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.08	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	58,393	—	≥ 20,000	PASS
Resolution to nearest impurity	vs O-desmethyl metabolite analogue (−14 Da)	2.02	—	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 58,393, and skew follows the reported asymmetry factor of 1.08. 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 0.04 % impurity against a 99.93 % 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	7.58	4,856,908	99.93	—
2	sulfonamide hydrolysis product (+18 Da)	7.15	1,944	0.04	+18.011
3	O-desmethyl metabolite analogue (−14 Da)	7.32	1,458	0.03	-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, unit-resolution instrument. Sticks are placed at m/z = (M + z × 1.007276)/z for the observed neutral mass of 624.2148 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	313.1147	-0.0016	51.4
1+	625.2254	625.2221	-0.0033	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)	99.90	99.93	divergence -0.03 pp vs batch median
Total impurities (% area)	-0.40	0.07
Largest single impurity (% area)	not stated	0.04
Water (%)	5.5	6.38
Counter-ion (%)	8.6	16.29
Peptide content (%w/w)	85.3	not determined
Endotoxin (EU/mg)	0.16	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: Supplier-supplied
Evidentiary weight: Weaker evidence. Read with the caveat below.
Chain of custody: Supplier despatch → laboratory direct (courier, cold pack, 10 d) → assay. Submitter did not handle the vial.
Assay date: 14 Feb 2026
Submitted to the index: 20 Feb 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.
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 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 TFC-2601-L7836 n=3

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-042110	TFC-2601-L7836	Janoshik	2026-Q1	99.93	6.79	102.3	Supplier-supplied	1	FAIL
AX-2026-042112	TFC-2601-L7836	Janoshik	2026-Q1	99.58	6.35	97.6	Supplier-supplied	1	FAIL

Batch rollup and reproducibility assessment →

Cross-sections

All MK-677 (Ibutamoren mesylate) records n=152
All TFC records n=573
All Kestrel records n=404
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 TFC records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-041932	Semaglutide	TFC-2604-X4301	Janoshik	2026-Q3	98.88	4.31	—	Supplier-supplied	0	PASS
AX-2026-042067	SS-31 (Elamipretide)	TFC-2604-Y7472	Kestrel	2026-Q3	98.66	4.44	—	Supplier-supplied	1	MARGINAL
AX-2026-042057	Sermorelin	TFC-2605-Y6440	Janoshik	2026-Q3	98.68	3.94	98.3	Supplier-supplied	0	PASS
AX-2026-041936	Semaglutide	TFC-2604-X4301	PeptideMeter	2026-Q3	98.62	4.30	—	Buyer-sourced	1	MARGINAL
AX-2026-041973	Humanin (HNG)	TFC-2605-U5564	Janoshik	2026-Q3	99.62	7.03	—	Supplier-supplied	2	FAIL
AX-2026-041980	Humanin (HNG)	TFC-2605-U5564	Janoshik	2026-Q3	99.90	7.01	88.6	Supplier-supplied	2	MARGINAL
AX-2026-041961	Tirzepatide	TFC-2605-G5134	Medutest	2026-Q3	98.25	7.11	—	Supplier-supplied	2	MARGINAL
AX-2026-042068	SS-31 (Elamipretide)	TFC-2604-Y7472	Medutest	2026-Q3	98.71	3.63	92.9	Supplier-supplied	2	MARGINAL