AX-2026-043185

PT-141 (Bremelanotide) · 10 mg declared · GL Biochem (Shanghai) Ltd. · lot GLBI-2511-F8417

FAILPURITY ONLY

Report ID: AX-2026-043185
Compound: PT-141 (Bremelanotide)
Compound class: Melanocortin-receptor peptides
Supplier: GL Biochem — GL Biochem (Shanghai) Ltd.
Batch / lot: GLBI-2511-F8417
Declared label claim: 10mg
Laboratory: Medutest
Assay date: 10 Jun 2026
Submitted: 14 Jun 2026
Quarter: 2026-Q2
Submitter: i.danquah
Sample provenance: Supplier-supplied

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, 25 min gradient, 214 nm	98.47	% area	≥ 98.5	FAIL
Total impurities	RP-HPLC, sum of reported peaks	1.53	% area	≤ 1.5	FAIL
Largest single impurity	RP-HPLC — melanotan II (C-terminal amide, −1 Da)	1.03	% area	≤ 1.00	FAIL
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	2.58	%	≤ 8.0	PASS
Counter-ion (acetate)	anion-exchange ion chromatography	5.14	%	≤ 10.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.50	%	—	NOT TESTED
Endotoxin	kinetic chromogenic LAL	1.30	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 cake, partial shrinkage from vial wall	—	white to off-white intact cake	FAIL
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	5.22	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 25 min gradient	8.25	min	8.06 ± 0.25 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.21	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	55,637	—	≥ 20,000	PASS
Resolution to nearest impurity	vs melanotan II (C-terminal amide, −1 Da)	1.86	—	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 55,637, and skew follows the reported asymmetry factor of 1.21. 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 1.03 % impurity against a 98.47 % 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	8.25	4,785,947	98.47	—
2	melanotan II (C-terminal amide, −1 Da)	8.52	50,061	1.03	-0.984
3	des-acetyl (−42 Da)	7.87	16,525	0.34	-42.011
4	linear precursor (+18 Da)	7.67	3,888	0.08	+18.011
5	oxidised Trp (+16 Da)	7.97	3,888	0.08	+15.995
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)	98.41	98.47	divergence +0.57 pp vs batch median
Total impurities (% area)	0.78	1.53
Largest single impurity (% area)	0.30	1.03
Water (%)	1.6	2.58
Counter-ion (%)	5.9	5.14
Peptide content (%w/w)	91.9	not determined
Endotoxin (EU/mg)	1.05	1.30
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, 6 d) → assay. Submitter did not handle the vial.
Assay date: 10 Jun 2026
Submitted to the index: 14 Jun 2026
Laboratory: Medutest, Ljubljana, Slovenia
Method basis: 25 min gradient · unit-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

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 GLBI-2511-F8417 n=7

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043181	GLBI-2511-F8417	PeptideMeter	2026-Q2	97.66	2.41	—	Supplier-supplied	2	FAIL
AX-2026-043182	GLBI-2511-F8417	Medutest	2026-Q2	97.57	2.36	93.0	Supplier-supplied	2	FAIL
AX-2026-043183	GLBI-2511-F8417	Janoshik	2026-Q2	97.84	1.92	—	Supplier-supplied	2	FAIL
AX-2026-043184	GLBI-2511-F8417	VendorInvestigate	2026-Q2	97.67	3.01	99.8	Buyer-sourced	2	FAIL
AX-2026-043186	GLBI-2511-F8417	PeptideMeter	2026-Q2	98.75	2.31	107.2	Supplier-supplied	2	MARGINAL
AX-2026-043187	GLBI-2511-F8417	Janoshik	2026-Q2	97.97	2.82	—	Supplier-supplied	2	FAIL

Batch rollup and reproducibility assessment →

Cross-sections

All PT-141 (Bremelanotide) records n=200
All GL Biochem records n=126
All Medutest records n=940
All 2026-Q2 records n=1009
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	Result
AX-2026-041488	QYB	QYB-2607-L5615	Janoshik	2026-Q3	99.93	3.79	—	Supplier-supplied	PASS
AX-2026-041483	QYB	QYB-2607-L5615	Janoshik	2026-Q3	99.93	3.87	—	Supplier-supplied	PASS
AX-2026-041482	QYB	QYB-2607-L5615	PeptideMeter	2026-Q3	99.41	3.97	—	Supplier-supplied	PASS
AX-2026-041489	QYB	QYB-2607-L5615	PeptideMeter	2026-Q3	99.40	4.39	90.1	Supplier-supplied	PASS
AX-2026-041480	QYB	QYB-2607-L5615	Medutest	2026-Q3	99.93	4.32	100.5	Supplier-supplied	PASS
AX-2026-041481	QYB	QYB-2607-L5615	Kestrel	2026-Q3	99.93	3.63	100.5	Supplier-supplied	PASS
AX-2026-041487	QYB	QYB-2607-L5615	Nordanalyt	2026-Q3	99.43	4.03	—	Supplier-supplied	PASS
AX-2026-041486	QYB	QYB-2607-L5615	Nordanalyt	2026-Q3	99.62	3.82	104.9	Supplier-supplied	PASS

Other recent GL Biochem records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043176	Kisspeptin-10	GLBI-2608-N8085	Medutest	2026-Q3	98.22	3.30	92.5	Buyer-sourced	2	FAIL
AX-2026-043180	Kisspeptin-10	GLBI-2608-N8085	Janoshik	2026-Q3	98.69	3.37	103.8	Supplier-supplied	2	MARGINAL
AX-2026-043178	Kisspeptin-10	GLBI-2608-N8085	Janoshik	2026-Q3	98.24	4.44	96.0	Supplier-supplied	2	FAIL
AX-2026-043177	Kisspeptin-10	GLBI-2608-N8085	Janoshik	2026-Q3	98.31	3.87	106.5	Buyer-sourced	2	FAIL
AX-2026-043202	Semaglutide	GLBI-2602-U8631	PeptideMeter	2026-Q3	96.77	6.38	89.7	Supplier-supplied	3	FAIL
AX-2026-043174	Kisspeptin-10	GLBI-2608-N8085	Medutest	2026-Q3	98.18	4.09	—	Laboratory-retained	2	FAIL
AX-2026-043201	Semaglutide	GLBI-2602-U8631	Janoshik	2026-Q3	96.91	5.77	91.2	Supplier-supplied	2	FAIL
AX-2026-043203	Semaglutide	GLBI-2602-U8631	Medutest	2026-Q3	97.45	6.09	—	Supplier-supplied	2	MARGINAL