AX-2025-018846 · Dihexa · FGP lot FGP-2408-S8496

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, 25 min gradient, 214 nm	99.46	% area	≥ 98.5	PASS
Total impurities	RP-HPLC, sum of reported peaks	0.54	% area	≤ 1.5	PASS
Largest single impurity	RP-HPLC — des-hexanoyl (−98 Da)	0.34	% area	≤ 1.00	PASS
Identity — theoretical monoisotopic mass	calculated from molecular formula	504.3312	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, unit resolution (single quadrupole)	504.3337	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	+5.0	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	7.03	%	≤ 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/	0.51	%	—	NOT TESTED
Endotoxin	not ordered on this submission	not determined	—	≤ 5.0	NOT TESTED
Sterility	membrane filtration, USP <71>, 14 d	No growth at 14 d	—	no growth	PASS
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	7.75	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 25 min gradient	9.35	min	10.36 ± 0.30 (normalised)	FAIL
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	0.94	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	60,721	—	≥ 20,000	PASS
Resolution to nearest impurity	vs [D-Ile]-epimer	0.75	—	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, 25 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 60,721, and skew follows the reported asymmetry factor of 0.94. 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 0.34 % impurity against a 99.46 % 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	9.35	4,834,064	99.46	—
2	des-hexanoyl (−98 Da)	7.33	16,525	0.34	-98.074
3	[D-Ile]-epimer	9.23	4,860	0.10	0.000
4	hexanoyl bis-adduct (+98 Da)	11.27	3,402	0.07	+98.074
5	free acid (+1 Da)	9.57	1,458	0.03	+0.984
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, unit-resolution instrument. Sticks are placed at m/z = (M + z × 1.007276)/z for the observed neutral mass of 504.3337 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	505.3410	0.0025	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)	99.78	99.46	divergence +0.19 pp vs batch median
Total impurities (% area)	0.22	0.54
Largest single impurity (% area)	0.11	0.34
Water (%)	4.9	7.03
Counter-ion (%)	9.0	N/A
Peptide content (%w/w)	85.5	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: Buyer-sourced
Evidentiary weight: Strongest available evidence in this index.
Chain of custody: Retail purchase → submitter (ambient, 2 d) → laboratory (hand-carried, 7 d) → assay.
Assay date: 03 Mar 2025
Submitted to the index: 13 Mar 2025
Laboratory: Medutest, Ljubljana, Slovenia
Method basis: 25 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 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 3

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.

aib_coupling13 Mar 2025

Hindered couplings are where a synthesis loses purity, and the deletion products they leave are the first thing to look for. On this record they are not there in quantity.

racemisation_ala13 Mar 2025

Epimerisation during activation produces a diastereomer that is mass-identical and only chromatographically separable. At this gradient length the separation exists, and 99.46 % is net of it.

sec_monomer13 Mar 2025

Where the close neighbour is an aggregate rather than a related substance, size exclusion separates them trivially and reverse phase never will.

Section 7

Related records

Same batch — lot FGP-2408-S8496 n=10

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2025-018847	FGP-2408-S8496	Nordanalyt	2025-Q1	99.65	6.46	—	Buyer-sourced	0	PASS
AX-2025-018848	FGP-2408-S8496	Janoshik	2025-Q1	99.15	7.18	97.8	Buyer-sourced	0	PASS
AX-2025-018849	FGP-2408-S8496	Kestrel	2025-Q1	99.56	6.94	—	Buyer-sourced	0	PASS
AX-2025-018850	FGP-2408-S8496	Kestrel	2025-Q1	99.69	7.31	95.1	Buyer-sourced	0	PASS
AX-2025-018851	FGP-2408-S8496	PeptideMeter	2025-Q1	99.33	6.53	88.9	Buyer-sourced	1	MARGINAL
AX-2025-018852	FGP-2408-S8496	Kestrel	2025-Q1	99.66	6.59	—	Laboratory-retained	0	PASS
AX-2025-018853	FGP-2408-S8496	Kestrel	2025-Q1	99.54	6.52	—	Buyer-sourced	1	FAIL
AX-2025-018854	FGP-2408-S8496	Medutest	2025-Q1	99.61	7.10	—	Buyer-sourced	0	PASS
AX-2025-018855	FGP-2408-S8496	Janoshik	2025-Q1	99.61	6.54	105.2	Buyer-sourced	0	PASS

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-2026-041370	WWB	WWB-2601-C4091	Kestrel	2026-Q2	99.93	11.05	—	Buyer-sourced	0	PASS
AX-2026-041521	QSC	QSC-2512-D5887	Janoshik	2026-Q2	99.64	6.16	—	Laboratory-retained	0	PASS
AX-2025-018407	WWB	WWB-2507-N1598	Janoshik	2025-Q3	99.61	9.31	—	Buyer-sourced	0	PASS
AX-2025-019342	HYB	HYB-2501-T6290	VendorInvestigate	2025-Q2	99.57	7.16	—	Buyer-sourced	1	MARGINAL
AX-2025-018408	WWB	WWB-2507-N1598	Janoshik	2025-Q3	99.79	8.96	—	Buyer-sourced	0	PASS
AX-2025-019344	HYB	HYB-2501-T6290	Kestrel	2025-Q2	99.93	6.63	—	Buyer-sourced	0	PASS
AX-2025-019343	HYB	HYB-2501-T6290	VendorInvestigate	2025-Q2	99.39	6.83	96.2	Buyer-sourced	0	PASS
AX-2025-019345	HYB	HYB-2501-T6290	Kestrel	2025-Q2	99.93	6.79	—	Buyer-sourced	0	PASS

Other recent FGP records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Result
AX-2026-041643	Semaglutide	FGP-2602-M8547	Janoshik	2026-Q3	99.31	2.79	100.7	Buyer-sourced	PASS
AX-2026-041638	Semaglutide	FGP-2602-M8547	Janoshik	2026-Q3	99.40	2.75	105.8	Buyer-sourced	PASS
AX-2026-041641	Semaglutide	FGP-2602-M8547	PeptideMeter	2026-Q3	98.98	2.38	105.0	Buyer-sourced	PASS
AX-2026-041610	Tirzepatide	FGP-2603-L7753	Janoshik	2026-Q3	98.81	2.45	101.0	Buyer-sourced	PASS
AX-2026-041637	Semaglutide	FGP-2602-M8547	PeptideMeter	2026-Q3	99.40	2.83	—	Laboratory-retained	PASS
AX-2026-041642	Semaglutide	FGP-2602-M8547	PeptideMeter	2026-Q3	98.78	2.24	—	Buyer-sourced	PASS
AX-2026-041609	Tirzepatide	FGP-2603-L7753	Janoshik	2026-Q3	98.52	2.00	98.0	Buyer-sourced	PASS
AX-2026-041636	Semaglutide	FGP-2602-M8547	Nordanalyt	2026-Q3	99.39	2.17	—	Buyer-sourced	PASS