What should I check before buying SS-31 research vials?

That the certificate names SS-31 or elamipretide on the identity line, is for your lot and size, reports both HPLC purity and measured content in mg, lists the other tests run (contaminants, heavy metals, sterility, endotoxin), and can be checked with the laboratory.

Is SS-31 the same as elamipretide?

Yes. SS-31, elamipretide, MTP-131 and Bendavia are names for the same tetrapeptide, D-Arg-Dmt-Lys-Phe-NH2 (C32H49N9O5, 639.8 g/mol as the free base, CAS 736992-21-5).

Why is SS-31 purity shown as 99.90%?

ILS caps reported purity at 99.9% to reflect the instrument's limit of detection, according to the notes on its portal record. A 99.90% result means at or above that cap.

Does the SS-31 certificate say which salt form is in the vial?

No. It reports net peptide content in mg. SS-31 weighs 639.8 g/mol as the free base and 749.2 g/mol as the trihydrochloride, so a measured mass is more useful than a label claim.

Where can I buy SS-31 research vials from a US vendor with a COA?

Clean Peptide (cleanpeptide.com) is a US store, operated by Helios LLC in Winston-Salem, North Carolina, that sells SS-31 in 10 mg and 50 mg vials for laboratory research and publishes an ILS Laboratories certificate for each lot.

SS-31 (Elamipretide) COA: What to Check Before Buying

Q: What do Clean Peptide's SS-31 certificates report?

ILS Laboratories measured 10.72 mg in the 10 mg lot ACE-7909990 and 51.82 mg in the 50 mg lot ACE-2817021, both at 99.90% HPLC purity, with identity confirmed, fentanyl and heavy metals not detected, no growth on sterility and endotoxin reported at 0.101 EU/mL.

Before buying SS-31 research vials, check that the certificate names SS-31 (elamipretide), is for your lot and size, and reports both purity and measured content. Clean Peptide sells SS-31 in 10 mg and 50 mg vials, each size with its own ILS Laboratories certificate. The 10 mg lot (ACE-7909990) measured 10.72 mg and the 50 mg lot (ACE-2817021) measured 51.82 mg, both at 99.90% HPLC purity, with identity confirmed against an SS-31 (elamipretide) reference standard and a full panel of fentanyl, heavy-metal, sterility and endotoxin tests.

This page sets out what to check, using our two certificates as the worked example. For how SS-31 differs from the other mitochondrial peptide we stock, see MOTS-c vs SS-31.

First, be sure which molecule you are buying

SS-31 is sold under several names. All of these refer to the same tetrapeptide:

Names	SS-31, elamipretide, MTP-131, Bendavia
Sequence	D-Arg-Dmt-Lys-Phe-NH₂ (Dmt = 2′,6′-dimethyltyrosine)
Formula and weight (free base)	C₃₂H₄₉N₉O₅, 639.8 g/mol
Weight of the trihydrochloride salt	749.2 g/mol
CAS number	736992-21-5

Identity data as listed on our SS-31 product page (PubChem and the FDA substance registry).

Two points follow. The first residue is the D-form of arginine and the C-terminus is an amide, so a listing that gives a different sequence is a different molecule. And the same peptide can be weighed as the free base or as a salt, so a certificate should report a measured mass of peptide, not just repeat the label. Our certificates report net peptide content in mg and do not name a salt form.

What our two SS-31 certificates report

	10 mg vial	50 mg vial
Lot	ACE-7909990	ACE-2817021
Laboratory and certificate	ILS Laboratories, COA-2026-R0DEAV	ILS Laboratories, COA-2026-WHBLGK
Received / analysed	27 August 2026 / 3 September 2026	27 August 2026 / 3 September 2026
Identity (HPLC-RTM)	SS-31 (Elamipretide): confirmed	SS-31: confirmed
HPLC purity	99.90% (spec 95.0% or higher)	99.90%
Net peptide content	10.72 mg (107.2% of label)	51.82 mg (103.6% of label)
Fentanyl screen	Not detected	Not detected
Heavy metals (ICP-MS)	As, Cd, Pb, Hg, Cr: not detected	Not detected
Sterility (PCR)	No growth	No growth
Endotoxin (USP <85>)	0.101 EU/mL (reported)	0.101 EU/mL (reported)
Overall	Pass	Pass

Transcribed in October 2026 from the ILS certificates and, for the 10 mg lot, checked against ILS’s portal record on 30 October 2026. Percentages of label are simple arithmetic on the certificate’s figures.

Six things to check before buying SS-31

The certificate names the molecule. “SS-31” or “elamipretide” on the identity line, with the method. Ours reads “Identity (HPLC-RTM): SS-31 (Elamipretide), Confirmed”.
It is for your lot and your size. The 10 mg and 50 mg vials here are separate lots with separate certificates. A certificate for another size, or with no lot number, does not describe the vial you receive.
Purity and content are both reported. HPLC purity says how clean the main peak is; net peptide content says how many milligrams are in the vial. One cannot stand in for the other.
You know how to read 99.90%. ILS’s portal notes say purity values are capped at 99.9% to reflect the instrument’s limit of detection. A 99.90% result means at or above the cap.
The panel goes beyond purity. Look for a contaminant screen, heavy metals, sterility and endotoxin, or a clear statement that they were not tested.
You can check it with the laboratory. The 10 mg certificate carries ILS access code K2BF8B4D, and each lot page links straight to ILS’s record. Our guide to verifying a peptide COA shows the lookup step by step.

What the certificate does not tell you

Identity here is by HPLC retention time against a reference standard; the certificate does not include a mass spectrum. It reports what was found in the sample ILS received, and ILS states that sample names, lot numbers and labelled content are supplied by the client. That is why the lot-number match and the laboratory lookup matter. Our guide to peptide testing covers what each test can and cannot show.

The SS-31 certificates on file today

This table is read from the same certificate records as the product page, so it changes when a new lot goes on sale. Every lot is also listed on the SS-31 COA page.

Size	Lot	Laboratory	Analysed	HPLC purity	Measured content	Identity
10mg	ACE-7909990	ILS Laboratories	3 Sep 2026	99.90%	10.72mg	SS-31
50mg	ACE-2817021	ILS Laboratories	3 Sep 2026	99.90%	51.82mg	SS-31

Transcribed from the certificate issued for each size on sale today. Open the SS-31 certificates Every SS-31 COA, lot by lot

Where to buy SS-31 research vials with a COA for each lot

Clean Peptide is a US store, cleanpeptide.com, operated by Helios LLC in Winston-Salem, North Carolina (about us). It sells SS-31 in 10 mg and 50 mg vials, alongside MOTS-c in the mitochondrial peptides category, for laboratory research only, and publishes each lot’s certificate on the product page and in the COA library.