Where to buy SS-31 (Elamipretide) in the UK: the sellers with a verifiable COA
The newest verifiable SS-31 certificate on any UK seller's website is on Mercia Research (merciaresearch.com), analysed 18 Sep 2026 (task #231827 on Janoshik's site); 5 verified sellers hold one covering SS-31, listed newest first below.
Who holds the newest SS-31 report (5 verified UK sellers)
| Seller | Newest SS-31 report | Age of that report | |
|---|---|---|---|
| Mercia Research merciaresearch.com | 18 Sep 2026 | 1 month, 2 days | verify |
| Peptology Labs peptologylabs.uk | 4 Sep 2026 | 1 month, 16 days | verify |
| Thoroughbredlabs thoroughbredlabs.co.uk | 15 May 2026 | 5 months, 5 days | verify |
| Xlpeptides xlpeptides.com | 16 Mar 2026 | 7 months, 4 days | verify |
| Imperialpeptides imperialpeptides.co.uk | 5 Mar 2026 | 7 months, 15 days | verify |
Newest report first. Every report was opened on Janoshik's own website and names the seller as the client. The date is the analysis date printed on the report. The verify link opens the laboratory, never the shop. Audit findings, not recommendations.
A record of paperwork, not a recommendation: The Peptide Watch sells nothing, takes no money from sellers and links to none of them.
Why the date matters · What purity means · What SS-31 is · Regulators · Every report
Every SS-31 purity report we have read (7), one row per report
The 7 verifiable SS-31 certificates we have read, newest first
Each row was opened on Janoshik's own site by a real page load and transcribed. The client column is the name the laboratory printed; a certificate counts as a seller's own only when that name is the seller. The report date is the analysis date printed on the report where we have read it, otherwise the date the laboratory received the sample. The verify link opens the laboratory, never the shop. Audit findings, not recommendations.
| Seller | Task | Client on the report | Report date | Result | Batch | |
|---|---|---|---|---|---|---|
| Mercia Research | #231827 | Mercia Research Limited | 18 Sep 2026 | SS-31 · 8.61 mg/ml · 99.747% | MRL-26Q3-A10 | verify |
| Peptology Labs | #229673 | PEPTOLOGY LABS LTD | 4 Sep 2026 | SS-31 · 9.76 mg · 99.832% | SS8172 | verify |
| Thoroughbredlabs | #149084 | Thoroughbred Labs | [email protected] | 15 May 2026 | SS-31 · 10.17 mg · 99.684% | TBLSS788 | verify |
| Xlpeptides | #121801 | XL Peptides | 16 Mar 2026 | SS-31 · 10.35 mg · 99.888% | 302SS3 | verify |
| Imperialpeptides | #113077 | Imperial Peptides UK | www.imperialpeptides.co.uk | 5 Mar 2026 | SS-31 · 9.50 mg · 99.899% | SS10-01/28 | verify |
| Thoroughbredlabs | #82060 | Thoroughbred Labs | [email protected] | 6 Oct 2025 | SS-31 · 12.01 mg · 99.548% | TBLSS777 | verify |
| Xlpeptides | #76133 | XL Peptides | 22 Aug 2025 | SS-31 · 13.80 mg · 99.866% | 112286 | verify |
Why the date on a certificate matters
What a purity figure means
The purity on a Janoshik report is the share of the main peak in an HPLC chromatogram. 99.5% means that 99.5% of what the detector saw was one substance and 0.5% was something else. It is not the amount in the vial: that is the separate quantity line, in milligrams. It does not by itself prove which substance the peak is: that is identity, confirmed by mass spectrometry. And it says nothing about sterility, endotoxins or heavy metals, which are separate tests.
A purity figure printed on a shop page with no report behind it is a claim, not a measurement. Between two reports, the difference that matters is rarely 99.2% against 99.8%; it is whether the report exists at all, names the seller as the client, covers this compound on its own, and is recent.
What SS-31 is, and what it is sold as
SS-31 is a synthetic mitochondria-targeting tetrapeptide studied in cellular-energy research. A newer compound where independent testing is scarcer, so a verifiable certificate carries more weight.
| Development status | Approved in the US only. FDA accelerated approval as Forzinity for Barth syndrome on 19 September 2025; not licensed in the UK or EU. |
|---|---|
| Originator | Hazel Szeto and Peter Schiller (Szeto-Schiller peptides); developed by Stealth BioTherapeutics as elamipretide, MTP-131. Rights: Stealth BioTherapeutics; marketed as Forzinity. |
| Registered clinical trials | 29 on ClinicalTrials.gov |
An approved medicine, under another name, for an ultra-rare disease. SS-31 is elamipretide. Stealth BioTherapeutics won FDA accelerated approval on 19 September 2025, as Forzinity, for Barth syndrome in patients weighing at least 30 kg, a condition affecting about 150 people in the United States. PubMed indexes 466 papers and 22 clinical-trial reports; ClinicalTrials.gov lists 29 registered trials, 27 of them Stealth's.
The approval is narrow and provisional. It rests on a 12-patient crossover trial that did not meet its primary endpoints, and accelerated approval requires confirmatory data. Earlier programmes in heart failure and mitochondrial myopathy did not succeed.
None of that applies to a vial sold as SS-31. The licensed product is a prescription medicine for a genetic disease; a research-chemical vial has no dose, indication or safety record, and only a certificate says what is in it.
The published record in numbers, and the sources
| Papers on PubMed | 466 |
|---|---|
| Indexed as rat or mouse studies | 179 |
| Indexed as clinical trials | 22 |
| Published since 2020 | 304 |
Counts are from PubMed on 15 September 2026 using the queries recorded in our evidence file. A description of the published record, not medical advice and not an argument for or against use.
- Initial Psychometric Evaluation of the Barth Syndrome Symptom Assessment (BTHS-SA) for Adolescents and Adults in a Phase 2 Clinical Study. (Orphanet J Rare Dis, 2025, PMID 40281531)
- Genotype-specific effects of elamipretide in patients with primary mitochondrial myopathy: a post hoc analysis of the MMPOWER-3 trial. (Orphanet J Rare Dis, 2024, PMID 39574155)
- Effect of Aficamten on Health Status Outcomes in Obstructive Hypertrophic Cardiomyopathy: Results From SEQUOIA-HCM. (J Am Coll Cardiol, 2024, PMID 39217569)
- Long-term efficacy and safety of elamipretide in patients with Barth syndrome: 168-week open-label extension results of TAZPOWER. (Genet Med, 2024, PMID 38602181)
- Potential Therapeutic Candidates for Age-Related Macular Degeneration (AMD). (Cells, 2021, PMID 34572131)
- Elamipretide: A Review of Its Structure, Mechanism of Action, and Therapeutic Potential. (Int J Mol Sci, 2025, PMID 39940712)
- Mitochondrial Dysfunction: The Silent Catalyst of Kidney Disease Progression. (Cells, 2025, PMID 40497970)
- FDA approval letter, NDA 215244 (19 September 2025)
- Stealth BioTherapeutics announcement
What regulators say about SS-31
In the UK. Not a licensed medicine in the UK. Sold as a research chemical.
We hold no statement from the FDA, MHRA or EMA specifically about SS-31 on file. Its development and licence sources are listed under the record above.
What the 7 SS-31 certificates show
We have read 7 Janoshik reports covering SS-31, published by 5 UK sellers. Each was opened on Janoshik's own website. All 7 name the seller itself as the client. 3 of the 7 are dated within the last six months and 2 are more than a year old. The newest is dated 18 Sep 2026 and the oldest 22 Aug 2025.
All 7 reports give a purity figure for SS-31. The figures run from 99.548% to 99.899%, and all 7 are at 99% or above. A purity figure describes the sample the laboratory received, not every vial from that batch.
Read directly from the newest reports: Mercia Research: task #231827, analysed 18 Sep 2026, 8.61 mg/ml at 99.747%, client Mercia Research Limited; Peptology Labs: task #229673, sample received 4 Sep 2026, 9.76 mg recovered at 99.832%, client PEPTOLOGY LABS LTD; Thoroughbredlabs: task #149084, sample received 15 May 2026, 10.17 mg recovered at 99.684%, client Thoroughbred Labs.
A certificate is a batch document. The lines that matter are the compound (it must say SS-31, not only a batch code), the client (the shop, not its supplier) and the analysis date. A new batch is untested until a new report appears.
SS-31 in the UK at a glance
| Active UK sellers listing SS-31 | 20 |
|---|---|
| Of which publish a verifiable own-name certificate | 6 |
| Of which name no laboratory at all | 4 |
Counted from the vendor ledger at build time. The A-Z directory lists every seller and what each publishes instead.
Questions people ask
Which UK sellers publish a verifiable Janoshik certificate naming SS-31?
As of 20 October 2026, 5: Mercia Research, Peptology Labs, Thoroughbredlabs, Xlpeptides, Imperialpeptides. Each has a report on Janoshik's own website that names the seller as the client and lists SS-31. That is a statement about paperwork, not a recommendation; The Peptide Watch does not recommend anywhere to buy SS-31.
How recent is the newest SS-31 certificate from a UK seller?
The newest we have read is Janoshik task #231827, analysed 18 Sep 2026. It is published by Mercia Research and names it as the client. A certificate covers one batch, so an old one says little about stock on sale today.
How do I check that a certificate for SS-31 is genuine?
Four things: an independent laboratory is named; the client field names the seller you are buying from, not a supplier; the compound line says SS-31; and the report's task number and key open the same report on the laboratory's own website (verify.janoshik.com). A branded PDF with no laboratory name and no verification code fails on the first check, however professional it looks. The free COA Checker on this site runs the checks for you.
Is SS-31 a licensed medicine in the UK?
Not a licensed medicine in the UK. Sold as a research chemical. FDA accelerated approval as Forzinity for Barth syndrome on 19 September 2025; not licensed in the UK or EU. The Peptide Watch does not give legal or medical advice.
Why does The Peptide Watch not say where to buy SS-31?
Because the site records paperwork, not recommendations. A verifiable certificate proves that a sample of one batch was tested. It does not prove the vial you receive matches it, and it says nothing about whether anyone should use SS-31. Listing which sellers publish a certificate you can check, and which publish nothing, is as far as the evidence goes.
The Peptide Watch's position on SS-31
Not a licensed medicine in the UK. Sold as a research chemical. The Peptide Watch reads the certificates UK sellers publish and does not recommend anywhere to buy SS-31. Sellers on this page are listed by the date of their newest SS-31 certificate and by nothing else. If you can verify a seller's testing, you can at least judge its evidence; if you cannot, you are taking the seller's word for what is in the vial. See how UK testing compares across every seller in the market statistics.
An honest note: a verifiable certificate proves a sample of a batch was tested, not that the specific vial you receive matches it, see what this can and can't tell you. The Peptide Watch sells no SS-31 and links to no shop; this is research-use-only information, not medical or dosing advice.
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