AX-2026-041563

PT-141 (Bremelanotide) · 10 mg declared · Qingdao Sigma Chemical Co., Ltd. · lot QSC-2511-W7580

MARGINALPURITY ONLY

Report ID: AX-2026-041563
Compound: PT-141 (Bremelanotide)
Compound class: Melanocortin-receptor peptides
Supplier: QSC — Qingdao Sigma Chemical Co., Ltd.
Batch / lot: QSC-2511-W7580
Declared label claim: 10mg
Laboratory: PeptideMeter
Assay date: 21 Dec 2025
Submitted: 03 Jan 2026
Quarter: 2025-Q4
Submitter: co.vasquez
Sample provenance: Buyer-sourced

Section 1

Results

Measured against the index acceptance specification for the melanocortin-receptor 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	≥ 98.5	PASS
Total impurities	RP-HPLC, sum of reported peaks	0.07	% area	≤ 1.5	PASS
Largest single impurity	RP-HPLC — melanotan II (C-terminal amide, −1 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	5.65	%	≤ 8.0	PASS
Counter-ion (acetate)	anion-exchange ion chromatography	4.16	%	≤ 10.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.98	%	—	NOT TESTED
Endotoxin	kinetic chromogenic LAL	2.59	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 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	5.42	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 28 min gradient	9.05	min	8.94 ± 0.25 (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	77,400	—	≥ 20,000	PASS
Resolution to nearest impurity	vs melanotan II (C-terminal amide, −1 Da)	2.24	—	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 77,400, 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 0.04 % 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	PT-141 (Bremelanotide) — main peak	9.05	4,856,908	99.93	—
2	melanotan II (C-terminal amide, −1 Da)	9.35	1,944	0.04	-0.984
3	linear precursor (+18 Da)	8.40	1,458	0.03	+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 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)	100.0	99.93	divergence +0.10 pp vs batch median
Total impurities (% area)	0.00	0.07
Largest single impurity (% area)	0.00	0.04
Water (%)	4.0	5.65
Counter-ion (%)	not stated	4.16
Peptide content (%w/w)	not stated	not determined
Endotoxin (EU/mg)	2.42	2.59
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, 15 d) → laboratory (courier, cold pack, 2 d) → assay.
Assay date: 21 Dec 2025
Submitted to the index: 03 Jan 2026
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 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 4

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.

wide_iqr03 Jan 2026

A single result at 99.93 % is one draw. What makes a supplier's process legible is the spread across its lots, and that is on the scorecard rather than here. This record is one good point in a distribution worth reading whole.

peak_integrator03 Jan 2026

The measured value on this record carries two decimals because the integration produced two. That is the honest form of the same quantity, and it is available from the supplier as well.

iso_audit03 Jan 2026

Under a quality system a result field and a specification field are different controlled fields, and conflating them is a document-control observation. It is also one of the easiest things in this whole market to fix.

sig_figs03 Jan 2026

Precision and accuracy are separate properties. A figure rounded to a half point can be more accurate than one printed to two decimals, and on this lot it is within a tenth of the independent median.

Section 7

Related records

Same batch — lot QSC-2511-W7580 n=2

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2025-018733	QSC-2511-W7580	Janoshik	2025-Q4	99.86	5.75	100.4	Buyer-sourced	1	MARGINAL

Batch rollup and reproducibility assessment →

Cross-sections

All PT-141 (Bremelanotide) records n=152
All QSC records n=350
All PeptideMeter records n=1116
All 2025-Q4 records n=762
PT-141 (Bremelanotide) by supplier
PT-141 (Bremelanotide) impurity profile

Other recent PT-141 (Bremelanotide) records in the index.
Report	Supplier	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-041471	QYB	QYB-2607-L4875	Janoshik	2026-Q3	99.72	3.75	101.7	Buyer-sourced	0	PASS
AX-2026-041473	QYB	QYB-2607-L4875	PeptideMeter	2026-Q3	99.58	3.74	94.4	Buyer-sourced	0	PASS
AX-2026-041472	QYB	QYB-2607-L4875	PeptideMeter	2026-Q3	99.93	3.94	—	Buyer-sourced	0	PASS
AX-2026-041474	QYB	QYB-2607-L4875	VendorInvestigate	2026-Q3	99.16	3.78	95.6	Buyer-sourced	0	PASS
AX-2026-041470	QYB	QYB-2607-L4875	Janoshik	2026-Q3	99.77	4.10	—	Buyer-sourced	0	PASS
AX-2026-042139	JEEP	JEEP-2601-K8195	VendorInvestigate	2026-Q2	98.32	4.29	99.4	Buyer-sourced	1	FAIL
AX-2026-041964	AMB	AMB-2601-M5602	Janoshik	2026-Q2	99.93	3.20	—	Buyer-sourced	0	PASS
AX-2026-041664	FGP	FGP-2602-Y8741	Janoshik	2026-Q2	99.90	4.48	106.5	Buyer-sourced	0	PASS

Other recent QSC records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-041599	CJC-1295 (no DAC)	QSC-2606-V7416	VendorInvestigate	2026-Q3	97.96	3.52	—	Buyer-sourced	1	FAIL
AX-2026-041601	CJC-1295 (no DAC)	QSC-2606-V7416	Kestrel	2026-Q3	98.33	4.10	—	Buyer-sourced	1	MARGINAL
AX-2026-041602	CJC-1295 (no DAC)	QSC-2606-V7416	VendorInvestigate	2026-Q3	98.36	3.38	101.8	Buyer-sourced	1	MARGINAL
AX-2026-041477	Triptorelin	QSC-2607-C5749	Nordanalyt	2026-Q3	99.53	3.42	—	Buyer-sourced	0	PASS
AX-2026-041600	CJC-1295 (no DAC)	QSC-2606-V7416	Nordanalyt	2026-Q3	97.74	4.91	100.9	Buyer-sourced	1	FAIL
AX-2026-041603	CJC-1295 (no DAC)	QSC-2606-V7416	PeptideMeter	2026-Q3	98.43	4.20	—	Buyer-sourced	1	MARGINAL
AX-2026-041606	CJC-1295 (no DAC)	QSC-2606-V7416	Janoshik	2026-Q3	98.03	3.58	—	Buyer-sourced	1	MARGINAL
AX-2026-041585	Liraglutide	QSC-2605-W7381	Medutest	2026-Q3	99.59	5.09	92.8	Laboratory-retained	0	PASS