AX-2025-018680 · Dihexa · QYB lot QYB-2503-Y6694

Section 1

Results

Measured against the index acceptance specification for the neuroactive and cognitive peptides 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, 35 min gradient, 214 nm	99.90	% area	≥ 98.5	PASS
Total impurities	RP-HPLC, sum of reported peaks	0.10	% area	≤ 1.5	PASS
Largest single impurity	RP-HPLC — des-hexanoyl (−98 Da)	0.06	% area	≤ 1.00	PASS
Identity — theoretical monoisotopic mass	calculated from molecular formula	504.3312	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, high resolution (ESI-TOF/QTOF)	504.3293	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	-3.8	ppm	± 15	PASS
Peptide content	not ordered on this submission	not determined	—	required to check label claim	NOT TESTED
Water content	Karl Fischer, coulometric, duplicate	7.77	%	≤ 12.0	PASS
Counter-ion	no ionisable counter-ion expected	N/A	—	not applicable	NOT TESTED
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.69	%	—	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, colourless, no visible particulates	—	clear, no visible particulates	PASS
pH (reconstituted, 1 mg/mL)	potentiometric, two-point calibration	6.90	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 35 min gradient	14.08	min	14.12 ± 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	53,422	—	≥ 20,000	PASS
Resolution to nearest impurity	vs [D-Ile]-epimer	0.65	—	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, 35 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 53,422, 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 0.06 % impurity against a 99.90 % 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	Dihexa — main peak	14.08	4,855,450	99.90	—
2	des-hexanoyl (−98 Da)	11.26	2,916	0.06	-98.074
3	free acid (+1 Da)	14.38	1,458	0.03	+0.984
4	[D-Ile]-epimer	13.92	486	0.01	0.000
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 504.3312 Da, computed from C27H44N4O5. 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 504.3293 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 (%)
1+	505.3385	505.3366	-0.0019	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	99.90	divergence -0.03 pp vs batch median
Total impurities (% area)	0.10	0.10
Largest single impurity (% area)	0.05	0.06
Water (%)	not stated	7.77
Counter-ion (%)	4.2	N/A
Peptide content (%w/w)	91.7	not determined
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: Supplier-supplied
Evidentiary weight: Weaker evidence. Read with the caveat below.
Chain of custody: Supplier despatch → laboratory direct (courier, cold pack, 8 d) → assay. Submitter did not handle the vial.
Assay date: 18 Sep 2025
Submitted to the index: 19 Sep 2025
Laboratory: Nordanalyt Laboratories, Uppsala, Sweden
Method basis: 35 min gradient · high-resolution MS
Verification status: IDENTITY CONSISTENT

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 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 QYB-2503-Y6694 n=12

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2025-018676	QYB-2503-Y6694	Medutest	2025-Q3	99.93	7.81	107.2	Supplier-supplied	1	MARGINAL
AX-2025-018677	QYB-2503-Y6694	Kestrel	2025-Q3	99.93	8.20	—	Supplier-supplied	1	MARGINAL
AX-2025-018678	QYB-2503-Y6694	Janoshik	2025-Q3	99.67	7.09	—	Supplier-supplied	1	MARGINAL
AX-2025-018679	QYB-2503-Y6694	Janoshik	2025-Q3	99.93	8.19	107.5	Supplier-supplied	1	MARGINAL
AX-2025-018681	QYB-2503-Y6694	Medutest	2025-Q3	99.88	7.09	100.0	Supplier-supplied	1	MARGINAL
AX-2025-018682	QYB-2503-Y6694	Kestrel	2025-Q3	99.93	7.88	—	Supplier-supplied	0	PASS
AX-2025-018683	QYB-2503-Y6694	Medutest	2025-Q3	99.93	7.57	—	Supplier-supplied	1	MARGINAL
AX-2025-018684	QYB-2503-Y6694	Janoshik	2025-Q3	99.93	7.93	91.4	Supplier-supplied	0	PASS
AX-2025-018685	QYB-2503-Y6694	Janoshik	2025-Q3	99.93	7.03	—	Supplier-supplied	1	MARGINAL
AX-2025-018686	QYB-2503-Y6694	Janoshik	2025-Q3	99.93	7.89	105.8	Supplier-supplied	0	PASS
AX-2025-018687	QYB-2503-Y6694	Medutest	2025-Q3	99.93	7.58	—	Supplier-supplied	1	MARGINAL

Batch rollup and reproducibility assessment →

Cross-sections

Other recent Dihexa records in the index.
Report	Supplier	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-041598	QSC	QSC-2512-D7108	VendorInvestigate	2026-Q2	98.98	6.85	99.4	Laboratory-retained	1	MARGINAL
AX-2026-041597	QSC	QSC-2512-D7108	PeptideMeter	2026-Q2	99.35	6.42	106.3	Supplier-supplied	1	MARGINAL
AX-2026-041370	WWB	WWB-2601-C4091	Kestrel	2026-Q2	99.49	10.92	—	Supplier-supplied	1	MARGINAL
AX-2026-041602	QSC	QSC-2512-D7108	Nordanalyt	2026-Q2	99.93	5.89	—	Supplier-supplied	0	PASS
AX-2026-041599	QSC	QSC-2512-D7108	Nordanalyt	2026-Q2	99.93	6.03	95.9	Supplier-supplied	0	PASS
AX-2026-041600	QSC	QSC-2512-D7108	Nordanalyt	2026-Q2	99.27	6.20	—	Supplier-supplied	1	MARGINAL
AX-2026-041601	QSC	QSC-2512-D7108	Janoshik	2026-Q2	99.28	6.50	—	Supplier-supplied	2	MARGINAL
AX-2026-042263	Homopeptide	HOMO-2509-M1537	Medutest	2026-Q1	99.58	6.75	—	Supplier-supplied	2	MARGINAL

Other recent QYB records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-041453	Retatrutide	QYB-2604-B5660	VendorInvestigate	2026-Q3	98.02	2.55	—	Buyer-sourced	1	MARGINAL
AX-2026-041454	Retatrutide	QYB-2604-B5660	Janoshik	2026-Q3	98.84	2.77	—	Supplier-supplied	1	MARGINAL
AX-2026-041538	Retatrutide	QYB-2602-G6308	Medutest	2026-Q3	98.50	2.85	—	Supplier-supplied	2	MARGINAL
AX-2026-041456	Retatrutide	QYB-2604-B5660	Janoshik	2026-Q3	98.23	3.24	—	Supplier-supplied	1	MARGINAL
AX-2026-041452	Retatrutide	QYB-2604-B5660	Nordanalyt	2026-Q3	98.50	3.36	—	Supplier-supplied	1	MARGINAL
AX-2026-041427	Ipamorelin	QYB-2605-H4298	Janoshik	2026-Q3	99.93	4.12	—	Supplier-supplied	0	PASS
AX-2026-041488	PT-141 (Bremelanotide)	QYB-2607-L5615	Janoshik	2026-Q3	99.93	3.79	—	Supplier-supplied	0	PASS
AX-2026-041459	Retatrutide	QYB-2604-B5660	VendorInvestigate	2026-Q3	97.91	2.84	92.2	Buyer-sourced	1	MARGINAL