AX-2026-043583 · SS-31 (Elamipretide) · SIG lot SIG-2512-6369

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, 35 min gradient, 214 nm	99.32	% area	≥ 98.5	PASS
Total impurities	RP-HPLC, sum of reported peaks	0.68	% area	≤ 1.5	PASS
Largest single impurity	RP-HPLC — des-Dmt (−193 Da)	0.33	% area	≤ 1.00	PASS
Identity — theoretical monoisotopic mass	calculated from molecular formula	639.3856	Da	—	NOT TESTED
Identity — observed monoisotopic mass	LC-MS, high resolution (ESI-TOF/QTOF)	639.3873	Da	—	NOT TESTED
Mass accuracy	observed vs theoretical	+2.7	ppm	± 15	PASS
Total peptide content	by difference from the gravimetric mass balance	83.03	%w/w	—	NOT TESTED
Target-compound content	total peptide content × purity	82.47	%w/w	—	NOT TESTED
Gross fill (as weighed)	five-place balance, under nitrogen	54.51	mg	50 mg declared	NOT TESTED
Recovered target peptide	gross fill × target content	44.954	mg	50 mg claim	NOT TESTED
Recovery against label claim	recovered ÷ claim	89.9	%	90.0 – 110.0	FAIL
Water content	Karl Fischer, coulometric, duplicate	7.05	%	≤ 9.0	PASS
Counter-ion (acetate)	anion-exchange ion chromatography	9.32	%	≤ 12.0	PASS
Residual solvent + inorganic residue	estimated — see /methods/residual-solvents-q3c/	0.60	%	—	NOT TESTED
Endotoxin	kinetic chromogenic LAL	0.28	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	6.30	—	2.5 – 8.0	PASS
Retention time (observed)	RP-HPLC, 35 min gradient	10.31	min	10.31 ± 0.25 (normalised)	PASS
Peak asymmetry (10 % height)	Ph. Eur. 2.2.46	1.12	—	0.80 – 1.50	PASS
Plate count, main peak	N = 5.54 (t/w½)²	72,683	—	≥ 20,000	PASS
Resolution to nearest impurity	vs [D-Arg1]-epimer	1.34	—	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, 35 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 72,683, and skew follows the reported asymmetry factor of 1.12. 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 0.33 % impurity against a 99.32 % 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	10.31	4,827,260	99.32	—
2	des-Dmt (−193 Da)	9.47	16,039	0.33	-193.110
3	C-terminal free acid (+1 Da)	10.54	7,776	0.16	+0.984
4	acetyl adduct (+42 Da)	10.94	5,346	0.11	+42.011
5	[D-Arg1]-epimer	10.10	3,888	0.08	0.000
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, high-resolution instrument. Sticks are placed at m/z = (M + z × 1.007276)/z for the observed neutral mass of 639.3873 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	320.7009	0.0008	53.7
1+	640.3929	640.3946	0.0017	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	7.05
Counter-ion (acetate)	ion chromatography	9.32
Residual solvent + inorganic residue	estimated	0.60
Total peptide content	by difference	83.03
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)	99.36	99.32	divergence +0.04 pp vs batch median
Total impurities (% area)	0.64	0.68
Largest single impurity (% area)	not stated	0.33
Water (%)	5.7	7.05
Counter-ion (%)	5.4	9.32
Peptide content (%w/w)	88.3	83.03
Endotoxin (EU/mg)	not stated	0.28
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 → third-party forwarder (2 d) → laboratory (courier, cold pack, 5 d) → assay.
Assay date: 26 Jan 2026
Submitted to the index: 02 Feb 2026
Laboratory: Nordanalyt Laboratories, Uppsala, Sweden
Method basis: 35 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 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.

sig_figs02 Feb 2026

Two decimal places on 99.32 % implies repeatability better than 0.01 pp, which no laboratory here claims. The number is sound; the printed precision is more than the method carries.

Index data team

Two decimal places are retained because the source reports carry them and truncating would discard information where a laboratory genuinely reports it. The uncertainty budget on /methods/uncertainty-budget/ is the right thing to read alongside any purity figure on this site.

price_per_mg02 Feb 2026

A retail purchase carries a price, which makes cost per milligram of recovered peptide computable. That is the comparison a buyer actually needs and it exists only for this provenance class.

quarter_over_quarter02 Feb 2026

A longitudinal set of retail purchases from one supplier across four quarters is the strongest supplier-level evidence available. Several contributors here are building exactly that.

valley_drop02 Feb 2026

des-Dmt (−193 Da) at 0.33 % elutes close enough to the main peak that drop-line and valley-to-valley will not agree. The index prints the resolution figure and applies no criterion to it — how close the nearest impurity sits is a property of the compound and the gradient, not of the system. What matters is that the convention used is stated.

Section 7

Related records

Same batch — lot SIG-2512-6369 n=8

Report	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043582	SIG-2512-6369	PeptideMeter	2026-Q1	99.44	6.73	—	Buyer-sourced	0	PASS
AX-2026-043584	SIG-2512-6369	PeptideMeter	2026-Q1	99.60	6.56	—	Buyer-sourced	1	MARGINAL
AX-2026-043585	SIG-2512-6369	Janoshik	2026-Q1	99.30	6.47	—	Buyer-sourced	0	PASS
AX-2026-043586	SIG-2512-6369	Janoshik	2026-Q1	99.31	6.75	103.8	Buyer-sourced	0	PASS
AX-2026-043587	SIG-2512-6369	Janoshik	2026-Q1	99.25	6.28	—	Buyer-sourced	0	PASS
AX-2026-043588	SIG-2512-6369	Janoshik	2026-Q1	99.93	6.85	92.5	Supplier-supplied	0	PASS
AX-2026-043589	SIG-2512-6369	Kestrel	2026-Q1	99.10	6.87	97.8	Buyer-sourced	0	PASS

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	Result
AX-2026-042222	TFC	TFC-2607-R9099	VendorInvestigate	2026-Q3	99.46	5.41	102.6	Buyer-sourced	PASS
AX-2026-042492	Homopeptide	HOMO-2604-D5484	Medutest	2026-Q3	99.93	2.40	—	Buyer-sourced	PASS
AX-2026-042226	TFC	TFC-2607-R9099	Janoshik	2026-Q3	99.62	5.47	—	Buyer-sourced	PASS
AX-2026-042491	Homopeptide	HOMO-2604-D5484	Kestrel	2026-Q3	99.93	3.24	—	Supplier-supplied	PASS
AX-2026-042495	Homopeptide	HOMO-2604-D5484	PeptideMeter	2026-Q3	99.93	3.22	105.9	Supplier-supplied	PASS
AX-2026-042220	TFC	TFC-2607-R9099	Janoshik	2026-Q3	99.83	4.90	105.2	Buyer-sourced	PASS
AX-2026-042344	TFC	TFC-2604-Y3208	Janoshik	2026-Q3	99.68	3.43	95.9	Buyer-sourced	PASS
AX-2026-042494	Homopeptide	HOMO-2604-D5484	Kestrel	2026-Q3	99.93	2.69	96.0	Buyer-sourced	PASS

Other recent SIG records in the index.
Report	Compound	Lot	Lab	Quarter	Purity %	Water %	Recovery %	Provenance	Flags	Result
AX-2026-043535	GHRP-2	SIG-2603-6031	Janoshik	2026-Q3	99.12	1.26	105.7	Buyer-sourced	0	PASS
AX-2026-043541	GHRP-2	SIG-2603-6031	PeptideMeter	2026-Q3	99.06	2.08	107.4	Buyer-sourced	1	MARGINAL
AX-2026-043539	GHRP-2	SIG-2603-6031	Janoshik	2026-Q3	98.95	1.74	100.4	Buyer-sourced	1	FAIL
AX-2026-043534	GHRP-2	SIG-2603-6031	Medutest	2026-Q3	99.11	2.15	89.8	Buyer-sourced	1	MARGINAL
AX-2026-043542	GHRP-2	SIG-2603-6031	VendorInvestigate	2026-Q3	99.05	1.43	—	Buyer-sourced	1	FAIL
AX-2026-043543	GHRP-2	SIG-2603-6031	Janoshik	2026-Q3	99.38	1.70	98.6	Buyer-sourced	0	PASS
AX-2026-043544	GHRP-2	SIG-2603-6031	PeptideMeter	2026-Q3	99.57	1.51	105.4	Buyer-sourced	0	PASS
AX-2026-043538	GHRP-2	SIG-2603-6031	Kestrel	2026-Q3	98.93	1.72	—	Buyer-sourced	0	FAIL