AX-2025-020504 · SS-31 (Elamipretide) · KP lot KP-2408-H6177

Section 1

Results

Measured against the index acceptance specification for the metabolic and mitochondrial 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	98.57	% area	≥ 98.5	PASS
Total impurities	RP-HPLC, sum of reported peaks	1.43	% area	≤ 1.5	PASS
Largest single impurity	RP-HPLC — [D-Arg1]-epimer	0.93	% area	≤ 1.00	PASS
Identity — theoretical monoisotopic mass	calculated from molecular formula	639.3856	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, unit resolution (single quadrupole)	639.3922	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	+10.4	ppm	± 15	PASS
Total peptide content	by difference from the gravimetric mass balance	87.54	%w/w	—	NOT TESTED
Target-compound content	total peptide content × purity	86.29	%w/w	—	NOT TESTED
Gross fill (as weighed)	five-place balance, under nitrogen	22.25	mg	20 mg declared	NOT TESTED
Recovered target peptide	gross fill × target content	19.200	mg	20 mg claim	NOT TESTED
Recovery against label claim	recovered ÷ claim	96.0	%	90.0 – 110.0	PASS
Water content	Karl Fischer, coulometric, duplicate	4.02	%	≤ 9.0	PASS
Counter-ion (acetate)	anion-exchange ion chromatography	7.54	%	≤ 12.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.90	%	—	NOT TESTED
Endotoxin	kinetic chromogenic LAL	0.62	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, partially collapsed	—	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	5.16	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 25 min gradient	7.47	min	7.57 ± 0.25 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.15	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	60,908	—	≥ 20,000	PASS
Resolution to nearest impurity	vs [D-Arg1]-epimer	1.21	—	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 60,908, and skew follows the reported asymmetry factor of 1.15. 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 0.93 % impurity against a 98.57 % 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	SS-31 (Elamipretide) — main peak	7.47	4,790,808	98.57	—
2	[D-Arg1]-epimer	7.32	45,201	0.93	0.000
3	C-terminal free acid (+1 Da)	7.64	15,553	0.32	+0.984
4	des-Dmt (−193 Da)	6.87	4,860	0.10	-193.110
5	acetyl adduct (+42 Da)	7.92	3,888	0.08	+42.011
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 639.3856 Da, computed from C32H49N9O5. 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 639.3922 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+	320.7001	320.7034	0.0033	58.0
1+	640.3929	640.3995	0.0066	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	4.02
Counter-ion (acetate)	ion chromatography	7.54
Residual solvent + inorganic residue	estimated	0.90
Total peptide content	by difference	87.54
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)	99.64	98.57	divergence +0.83 pp vs batch median
Total impurities (% area)	0.85	1.43
Largest single impurity (% area)	not stated	0.93
Water (%)	not stated	4.02
Counter-ion (%)	not stated	7.54
Peptide content (%w/w)	not stated	87.54
Endotoxin (EU/mg)	not stated	0.62
Method stated on certificate	NO	—	no method section — the result cannot be reconciled against any other

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 → third-party forwarder (21 d) → laboratory (courier, cold pack, 4 d) → assay.
Assay date: 16 Jan 2025
Submitted to the index: 20 Jan 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.
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 KP-2408-H6177 n=6

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2025-020505	KP-2408-H6177	Medutest	2025-Q1	99.04	3.66	96.1	Supplier-supplied	2	MARGINAL
AX-2025-020506	KP-2408-H6177	PeptideMeter	2025-Q1	99.69	3.98	—	Supplier-supplied	3	MARGINAL
AX-2025-020507	KP-2408-H6177	PeptideMeter	2025-Q1	98.39	3.98	104.9	Buyer-sourced	1	FAIL
AX-2025-020508	KP-2408-H6177	Janoshik	2025-Q1	99.67	3.72	—	Supplier-supplied	3	MARGINAL
AX-2025-020509	KP-2408-H6177	Janoshik	2025-Q1	98.43	3.75	107.0	Supplier-supplied	2	FAIL

Batch rollup and reproducibility assessment →

Cross-sections

Other recent SS-31 (Elamipretide) records in the index.
Report	Supplier	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-042067	TFC	TFC-2604-Y7472	Kestrel	2026-Q3	98.66	4.44	—	Supplier-supplied	1	MARGINAL
AX-2026-042068	TFC	TFC-2604-Y7472	Medutest	2026-Q3	98.71	3.63	92.9	Supplier-supplied	2	MARGINAL
AX-2026-042069	TFC	TFC-2604-Y7472	Janoshik	2026-Q3	98.16	3.65	—	Supplier-supplied	2	FAIL
AX-2026-042070	TFC	TFC-2604-Y7472	PeptideMeter	2026-Q3	98.09	3.60	97.9	Supplier-supplied	1	FAIL
AX-2026-042072	TFC	TFC-2604-Y7472	VendorInvestigate	2026-Q3	97.88	3.47	89.5	Buyer-sourced	2	FAIL
AX-2026-042236	Homopeptide	HOMO-2604-D1599	PeptideMeter	2026-Q3	99.61	2.79	—	Supplier-supplied	0	PASS
AX-2026-041951	TFC	TFC-2607-R4363	Medutest	2026-Q3	99.56	5.16	—	Buyer-sourced	0	PASS
AX-2026-042071	TFC	TFC-2604-Y7472	PeptideMeter	2026-Q3	97.71	3.47	93.0	Laboratory-retained	2	FAIL

Other recent KP records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043029	Retatrutide	KP-2607-H5219	Medutest	2026-Q3	95.45	5.71	—	Supplier-supplied	2	FAIL
AX-2026-043030	Retatrutide	KP-2607-H5219	Kestrel	2026-Q3	95.97	6.95	97.1	Supplier-supplied	2	FAIL
AX-2026-043106	Tirzepatide	KP-2608-D5921	PeptideMeter	2026-Q3	98.90	5.45	105.4	Supplier-supplied	2	MARGINAL
AX-2026-043108	Tirzepatide	KP-2608-D5921	Janoshik	2026-Q3	99.70	5.45	—	Supplier-supplied	2	MARGINAL
AX-2026-043039	Retatrutide	KP-2607-H5219	Janoshik	2026-Q3	96.14	5.62	—	Supplier-supplied	2	FAIL
AX-2026-043100	Tirzepatide	KP-2608-D5921	VendorInvestigate	2026-Q3	98.27	5.31	94.4	Buyer-sourced	2	MARGINAL
AX-2026-043090	Ipamorelin	KP-2606-D5887	Janoshik	2026-Q3	98.18	3.07	101.2	Laboratory-retained	1	FAIL
AX-2026-043028	Retatrutide	KP-2607-H5219	Janoshik	2026-Q3	96.52	6.09	—	Supplier-supplied	2	MARGINAL