AX-2025-019254 · Selank · TFC lot TFC-2511-C6410

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, 32 min gradient, 214 nm	99.36	% area	≥ 99.0	PASS
Total impurities	RP-HPLC, sum of reported peaks	0.64	% area	≤ 1.0	PASS
Largest single impurity	RP-HPLC — acetyl adduct (+42 Da)	0.36	% area	≤ 1.00	PASS
Identity — theoretical monoisotopic mass	calculated from molecular formula	751.4402	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, high resolution (ESI-TOF/QTOF)	751.4431	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	+3.9	ppm	± 15	PASS
Total peptide content	by difference from the gravimetric mass balance	84.33	%w/w	—	NOT TESTED
Target-compound content	total peptide content × purity	83.79	%w/w	—	NOT TESTED
Gross fill (as weighed)	five-place balance, under nitrogen	21.48	mg	20 mg declared	NOT TESTED
Recovered target peptide	gross fill × target content	17.998	mg	20 mg claim	NOT TESTED
Recovery against label claim	recovered ÷ claim	90.0	%	90.0 – 110.0	PASS
Water content	Karl Fischer, coulometric, duplicate	8.01	%	≤ 12.0	PASS
Counter-ion (acetate)	anion-exchange ion chromatography	6.70	%	≤ 10.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.96	%	—	NOT TESTED
Endotoxin	kinetic chromogenic LAL	3.92	EU/mg	≤ 5.0	PASS
Sterility	not ordered on this submission	not determined	—	no growth	NOT TESTED
Appearance	visual, diffuse light, black and white background	White to pale-yellow 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	5.07	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 32 min gradient	6.64	min	6.81 ± 0.25 (normalised)	PASS
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	62,055	—	≥ 20,000	PASS
Resolution to nearest impurity	vs diketopiperazine (−18 Da)	1.76	—	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 62,055, 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 0.36 % impurity against a 99.36 % 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	6.64	4,829,204	99.36	—
2	acetyl adduct (+42 Da)	7.00	17,497	0.36	+42.011
3	tuftsin fragment (−417 Da)	5.98	5,832	0.12	-417.235
4	des-Thr (−101 Da)	6.36	4,374	0.09	-101.048
5	diketopiperazine (−18 Da)	6.83	3,402	0.07	-18.011
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 751.4402 Da, computed from C33H57N11O9. 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 751.4431 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+	376.7274	376.7288	0.0014	58.1
1+	752.4475	752.4504	0.0029	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	8.01
Counter-ion (acetate)	ion chromatography	6.70
Residual solvent + inorganic residue	estimated	0.96
Total peptide content	by difference	84.33
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)	99.90	99.36	divergence -0.02 pp vs batch median
Total impurities (% area)	0.10	0.64
Largest single impurity (% area)	0.07	0.36
Water (%)	6.5	8.01
Counter-ion (%)	4.4	6.70
Peptide content (%w/w)	88.5	84.33
Endotoxin (EU/mg)	not stated	3.92
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: Domestic warehouse despatch → submitter (2–8 °C, 1 d) → laboratory (courier, cold pack, 4 d) → assay.
Assay date: 31 Oct 2025
Submitted to the index: 18 Nov 2025
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 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-2511-C6410 n=6

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2025-019253	TFC-2511-C6410	PeptideMeter	2025-Q4	99.93	7.96	93.1	Supplier-supplied	0	PASS
AX-2025-019255	TFC-2511-C6410	Janoshik	2025-Q4	99.43	8.32	95.5	Supplier-supplied	0	PASS
AX-2025-019256	TFC-2511-C6410	Medutest	2025-Q4	99.90	8.16	99.1	Supplier-supplied	2	FAIL
AX-2025-019257	TFC-2511-C6410	Janoshik	2025-Q4	99.93	7.97	—	Supplier-supplied	0	PASS
AX-2025-019258	TFC-2511-C6410	Janoshik	2025-Q4	99.93	8.34	99.4	Supplier-supplied	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-2026-042737	GGPeps	GGPE-2603-J9708	Janoshik	2026-Q3	98.40	9.14	97.4	Buyer-sourced	0	FAIL
AX-2026-042804	GGPeps	GGPE-2602-G2056	Janoshik	2026-Q3	98.50	7.97	—	Supplier-supplied	0	FAIL
AX-2026-042803	GGPeps	GGPE-2602-G2056	Janoshik	2026-Q3	98.48	8.01	—	Laboratory-retained	1	FAIL
AX-2026-042802	GGPeps	GGPE-2602-G2056	Janoshik	2026-Q3	98.74	7.09	96.0	Supplier-supplied	0	FAIL
AX-2026-042796	GGPeps	GGPE-2602-G2056	Janoshik	2026-Q3	98.26	7.56	97.5	Buyer-sourced	0	FAIL
AX-2026-042797	GGPeps	GGPE-2602-G2056	Medutest	2026-Q3	98.46	7.92	—	Buyer-sourced	0	FAIL
AX-2026-042743	GGPeps	GGPE-2603-J9708	Medutest	2026-Q3	99.59	9.37	—	Supplier-supplied	0	PASS
AX-2026-042799	GGPeps	GGPE-2602-G2056	Nordanalyt	2026-Q3	98.77	8.33	—	Supplier-supplied	0	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