AX-2025-018572

Selank · 5 mg declared · ChinaPeptides Co., Ltd. (QYAOBIO) · lot QYB-2501-T4869

PASSPURITY ONLY

Report ID: AX-2025-018572
Compound: Selank
Compound class: Neuroactive and cognitive peptides
Supplier: QYB — ChinaPeptides Co., Ltd. (QYAOBIO)
Batch / lot: QYB-2501-T4869
Declared label claim: 5mg
Laboratory: PeptideMeter
Assay date: 18 Apr 2025
Submitted: 06 May 2025
Quarter: 2025-Q2
Submitter: z.chowdhury
Sample provenance: Buyer-sourced

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, 28 min gradient, 214 nm	99.93	% area	≥ 99.0	PASS
Total impurities	RP-HPLC, sum of reported peaks	0.07	% area	≤ 1.0	PASS
Largest single impurity	RP-HPLC — tuftsin fragment (−417 Da)	0.04	% area	≤ 1.00	PASS
Identity	not ordered on this submission	not determined	—	required for VERIFIED status	NOT TESTED
Peptide content	not ordered on this submission	not determined	—	required to check label claim	NOT TESTED
Water content	Karl Fischer, coulometric, duplicate	7.33	%	≤ 12.0	PASS
Counter-ion (acetate)	anion-exchange ion chromatography	7.29	%	≤ 10.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.87	%	—	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 cake, partial shrinkage from vial wall	—	white to off-white intact cake	FAIL
Reconstitution clarity	reconstituted per submitter procedure	Faint haze, clearing on standing	—	clear, no visible particulates	FAIL
pH (reconstituted, 1 mg/mL)	potentiometric, two-point calibration	3.94	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 28 min gradient	5.99	min	6.03 ± 0.25 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.17	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	77,283	—	≥ 20,000	PASS
Resolution to nearest impurity	vs des-Thr (−101 Da)	2.75	—	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, 28 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 77,283, and skew follows the reported asymmetry factor of 1.17. 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	Selank — main peak	5.99	4,856,908	99.93	—
2	tuftsin fragment (−417 Da)	5.41	1,944	0.04	-417.235
3	des-Thr (−101 Da)	5.75	1,458	0.03	-101.048
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 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)	99.57	99.93	divergence -0.21 pp vs batch median
Total impurities (% area)	0.43	0.07
Largest single impurity (% area)	0.30	0.04
Water (%)	6.3	7.33
Counter-ion (%)	not stated	7.29
Peptide content (%w/w)	88.9	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 (−20 °C, 14 d) → laboratory (courier, dry ice, 3 d) → assay.
Assay date: 18 Apr 2025
Submitted to the index: 06 May 2025
Laboratory: PeptideMeter, Tallinn, Estonia
Method basis: 28 min gradient · high-resolution MS
Verification status: PURITY ONLY

What this report does not establish

That the compound is the compound named. No identity confirmation was ordered on this submission. A purity figure describes chromatographic homogeneity of whatever eluted; it does not name it.
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 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.

c18_2p606 May 2025

Column chemistry flatters or punishes a figure like this. A core-shell column at this gradient resolves the close-eluting family that a fully porous 5 µm bed merges, so 99.93 % here is a harder number than the same figure from a coarser column.

lot_traceability06 May 2025

Lot QYB-2501-T4869 decodes to a manufacture date consistent with the custody chain above. Traceability plus 99.93 % is a complete story; either alone is half of one.

cleavage_cocktail06 May 2025

Alkylation artefacts from a scavenger-poor cleavage would appear as a +58 or +76 family here. Absent, which says the cleavage was run properly.

Section 7

Related records

Same batch — lot QYB-2501-T4869 n=2

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2025-018571	QYB-2501-T4869	Janoshik	2025-Q2	99.63	7.55	—	Buyer-sourced	0	PASS

Batch rollup and reproducibility assessment →

Cross-sections

Other recent Selank records in the index.
Report	Supplier	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-042858	GGPeps	GGPE-2603-J2447	VendorInvestigate	2026-Q3	98.87	8.85	99.4	Buyer-sourced	0	FAIL
AX-2026-042859	GGPeps	GGPE-2603-J2447	PeptideMeter	2026-Q3	98.92	9.48	103.5	Buyer-sourced	0	FAIL
AX-2026-041759	TFS	TFS-{CAT}-1712	Janoshik	2026-Q2	99.93	8.13	102.2	Buyer-sourced	0	PASS
AX-2026-042912	GGPeps	GGPE-2601-J3130	Janoshik	2026-Q2	99.75	9.44	89.7	Buyer-sourced	1	MARGINAL
AX-2026-041760	TFS	TFS-{CAT}-1712	Janoshik	2026-Q2	99.82	7.70	—	Buyer-sourced	0	PASS
AX-2026-041752	TFS	TFS-{CAT}-1712	Medutest	2026-Q2	99.63	7.43	—	Buyer-sourced	1	FAIL
AX-2026-042915	GGPeps	GGPE-2601-J3130	PeptideMeter	2026-Q2	99.53	10.03	—	Buyer-sourced	0	PASS
AX-2026-042910	GGPeps	GGPE-2601-J3130	VendorInvestigate	2026-Q2	99.62	9.21	105.0	Buyer-sourced	0	PASS

Other recent QYB records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-041471	PT-141 (Bremelanotide)	QYB-2607-L4875	Janoshik	2026-Q3	99.72	3.75	101.7	Buyer-sourced	0	PASS
AX-2026-041377	Ipamorelin	QYB-2605-H3558	Nordanalyt	2026-Q3	99.93	4.35	—	Buyer-sourced	0	PASS
AX-2026-041427	Retatrutide	QYB-2604-B4920	PeptideMeter	2026-Q3	97.93	2.45	101.7	Buyer-sourced	0	PASS
AX-2026-041428	Retatrutide	QYB-2604-B4920	Janoshik	2026-Q3	98.35	3.20	—	Laboratory-retained	0	PASS
AX-2026-041473	PT-141 (Bremelanotide)	QYB-2607-L4875	PeptideMeter	2026-Q3	99.58	3.74	94.4	Buyer-sourced	0	PASS
AX-2026-041472	PT-141 (Bremelanotide)	QYB-2607-L4875	PeptideMeter	2026-Q3	99.93	3.94	—	Buyer-sourced	0	PASS
AX-2026-041429	Retatrutide	QYB-2604-B4920	Medutest	2026-Q3	98.53	2.69	99.8	Buyer-sourced	1	MARGINAL
AX-2026-041431	Retatrutide	QYB-2604-B4920	Janoshik	2026-Q3	98.63	2.32	94.2	Buyer-sourced	0	PASS