SS-31 is elamipretide (also MTP-131, formerly Bendavia), a mitochondria-targeting tetrapeptide that binds cardiolipin on the inner mitochondrial membrane. On 19 September 2025 FDA granted it accelerated approval as Forzinity for Barth syndrome, in patients weighing at least 30 kg; it is approved for nothing else. Vendor-sold "SS-31" is research-grade material, not the approved drug. Across 37 public lab results for vendor SS-31 (26 clients, mirrors to 2 August 2026), none measured under 90% of label, median purity was 99.88% and one failed on identity. On 28 October 2026 our price index listed it at $2.59 to $5.00 per mg.
Research notes
SS-31 and elamipretide are the same molecule. It is FDA-approved for one use only: as Forzinity, for Barth syndrome, since 19 September 2025. The "SS-31" sold by peptide shops is research-grade material, not that drug.
Vendor SS-31 on the public record: 37 lab results from 26 clients, none under 90% of the labelled amount, and a median purity of 99.88%. The testing section has every Kovera Labs report, the price section the per-mg range on 28 October 2026, and the legal section the regulatory record.
How does SS-31 work?
SS-31 is a small mitochondria-targeting tetrapeptide. Its alternating aromatic-cationic structure lets it cross cell membranes and concentrate on the inner mitochondrial membrane, where it binds cardiolipin — the signature phospholipid that scaffolds the electron-transport chain. By stabilizing cardiolipin and cristae architecture, it improves electron-transport efficiency and reduces the reactive-oxygen-species (ROS) leak that drives mitochondrial damage.
Unlike general antioxidants, the effect is structural: it protects the place where energy is actually made, which is why research interest centers on high-energy tissue (heart, skeletal muscle, kidney, retina) and on aging models where mitochondrial function declines.
How pure is the SS-31 being sold?
We pooled every public SS-31 result in our lab mirrors (Kovera Labs, Janoshik and lab archives that vendors publish), mirrored up to 2 August 2026, and removed duplicate copies of the same test. That leaves 37 results from 26 clients.
| Measure | Result |
|---|---|
| Results | 37 |
| Clients | 26 |
| Median purity (37) | 99.88% |
| Lowest purity | 98.81% |
| Median content vs label (35 with a measured quantity) | 108.5% |
| Under 90% of label | 0 |
| Under 95% of label | 1 (2.9%) |
| Over 110% of label | 16 (45.7%) |
| Explicit fails | 1 |
| Identity not confirmed | 1 |
Download: the per-compound table is on our data page.
The one fail is a Glacier Aminos report sold under the name "MTP-31" (KVR-2026-2C8A1B, 11 May 2026): Kovera printed identity and net content as "Unknown". It does not say a different compound was found. Overfill is the more common pattern: 16 of 35 held more than 110% of the stated amount.
All 33 Kovera SS-31 reports
Vendors submit SS-31 to Kovera Labs under several product names ("SS-31", "§-31", "MTP-31", "S-31-S", "HTC - 31"). Our mirror holds 33 vial reports listed as SS-31, analysed 7 February to 31 May 2026, plus one add-on panel not shown here. Median purity 99.89%; median content 109.6% of label (32 with a measured quantity, range 94.3% to 128.8%). The lowest is a Zenith Bioscience 10 mg vial at 9.43 mg.
| Client on report | Product name | Label | Measured | Purity | Report | Lot | Tested |
|---|---|---|---|---|---|---|---|
| not shown | SS-31 | 50 mg | 55.59 mg (111.2%) | 99.92% | 64B08E | SS202602 | 2026-02-07 |
| not shown | SS-31 | 35 mg | 37.96 mg (108.5%) | 99.49% | 570445 | ES2S3450B1 | 2026-02-08 |
| not shown | SS-31 | 35 mg | 37.96 mg (108.5%) | 99.49% | 10E7FC | ES2S3450B1 | 2026-02-08 |
| Fixion Fuel | SS-31 | 10 mg | 11.73 mg (117.3%) | 99.97% | 8B58F | FF-SS10-0103 | 2026-03-07 |
| Fixion Fuel | SS-31 | 10 mg | 11.54 mg (115.4%) | 99.98% | 8B58E | FF-SS10-1121 | 2026-03-07 |
| Glacier Aminos | SS-31 | 10 mg | 10.63 mg (106.3%) | 99.94% | 4C8CEF | MTP10GA-03 | 2026-03-13 |
| Mile High Compounds | SS-31 | 10 mg | 11.42 mg (114.2%) | 99.95% | 384766 | SS3-010-MH-05 | 2026-03-20 |
| Ion Peptide | §-31 | 50 mg | 52.76 mg (105.5%) | 99.93% | 240A89 | §-3150-03232026 | 2026-03-24 |
| Ion Peptide | §-31 | 10 mg | 10.51 mg (105.1%) | 99.95% | 06020E | §-3110-03242026 | 2026-03-28 |
| Instant Peptides | SS-31 | 10 mg | 11.11 mg (111.1%) | 99.98% | C1CEED | 2026-0292-D | 2026-03-29 |
| Peak Chain / Genetix Chain | SS-31 | 10 mg | 11.81 mg (118.1%) | 99.97% | A011AA | 1111-0919 | 2026-03-29 |
| Snap Peptides | SS-31 | 10 mg | 11.38 mg (113.8%) | 99.96% | E5F3AC | SP26-SS3110-01 | 2026-03-31 |
| Peptide Partners | SS-31 | 10 mg | 11.73 mg (117.3%) | 99.91% | 030E88 | SS202601 | 2026-04-10 |
| Ion Peptide | §-31 | 10 mg | 11.68 mg (116.8%) | 99.85% | 59478B | 2S10-04202026 | 2026-04-22 |
| Hamner Research | SS-31 | 10 mg | 11.87 mg (118.7%) | 99.80% | A7C12B | HAM-B1-028 | 2026-04-25 |
| Plum Labs Research | SS-31 | 10 mg | 9.58 mg (95.8%) | 99.89% | A4714F | PLY-SS-102 | 2026-04-26 |
| D&H Peps | SS-31 | 10 mg | 9.83 mg (98.3%) | 99.92% | A50AF0 | Ss10426A | 2026-05-06 |
| Peptideresearchsupply.com | SS-31 | 20 mg | 20.46 mg (102.3%) | 99.89% | 51F2D9 | NA3-26A01 | 2026-05-06 |
| BioQuantum Sciences | SS-31 | 50 mg | 51.63 mg (103.3%) | 99.87% | 963483 | QC 08 10 | 2026-05-08 |
| Novagen USA | SS-31 | 10 mg | 11.21 mg (112.1%) | 99.98% | 62B082 | SS311002 | 2026-05-08 |
| Ascension Peptides | SS-31 | 10 mg | 10.83 mg (108.3%) | 99.89% | CE8ACD | 40-05260628 | 2026-05-09 |
| Glacier Aminos | MTP-31 | not stated | not reported | 99.88%, identity Unknown, fail | 2C8A1B | SS10GA-04 | 2026-05-11 |
| Upgrade | SS-31 | 10 mg | 9.74 mg (97.4%) | 99.99% | 7905C1 | 70-202604-68 | 2026-05-13 |
| Zenith Bioscience | SS-31 | 10 mg | 9.43 mg (94.3%) | 99.88% | BCA856 | ZB2605090001 | 2026-05-15 |
| Ion Peptide | §-31 | 10 mg | 11.02 mg (110.2%) | 99.97% | DCBA2D | 2S10-05142026 | 2026-05-19 |
| Mile High Compounds | SS-31 | 10 mg | 11.44 mg (114.4%) | 99.86% | CDDC7F | SS3-010-MH-06 | 2026-05-20 |
| Orbitrex Peptides | SS-31 | 10 mg | 10.79 mg (107.9%) | 98.97% | 88D259 | MTP10626 | 2026-05-20 |
| Inno Amino LLC | SS-31 | 10 mg | 10.03 mg (100.3%) | 99.66% | 0484C9 | SS3LIL-0415-26 | 2026-05-21 |
| Glacier Aminos | S-31-S | 10 mg | 11.82 mg (118.2%) | 99.61% | 046AFE | SS10GA-05 | 2026-05-21 |
| High Tide Compounds | HTC - 31 | 10 mg | 10.83 mg (108.3%) | 98.81% | F75862 | 3110-001 | 2026-05-26 |
| Lost Coast Aminos | SS-31 | 10 mg | 10.89 mg (108.9%) | 99.30% | B1AD11 | LCA05262S10 | 2026-05-28 |
| not named (client email) | SS-31 | 10 mg | 12.88 mg (128.8%) | 99.43% | 4D271B | FF-SS10-0518 | 2026-05-28 |
| Zenergy | SS-31 | 30 mg | 34.23 mg (114.1%) | 99.83% | 729637 | ZEN51826 | 2026-05-31 |
Values are single-vial figures as held in our mirror after the 1 August 2026 re-fetch. Kovera revises some certificates in place (what changed), so its verifier may show slightly different figures. Two reports dated 8 February 2026 share one lot and identical results.
One SS-31 analysis, three brand names
Nexaph, Ameano and EZ Peptides each show the same Janoshik analysis of SS-31 batch ATP3005072026-01 (30 mg, tested 25 May 2026) on consecutive task numbers 163730 to 163732: 28.26, 28.70 and 28.31 mg, or 94% to 96% of label, at 99.66% to 99.72% purity. The brands' own lab pages report these figures; Janoshik's verifier blocked our requests, so the client names on the reports are unconfirmed. The record is in our Nexaph, EZ Peptides and Ameano report.
A certificate covers the batch that was tested, not the vial in your hand. Match the lot on the vial to the lot on the report, and check a Kovera code yourself with the verification steps.
What does SS-31 cost per mg?
Our price index, built 28 October 2026 from public product pages, holds three SS-31 listings from two vendors.
| Vendor | Vial | Price | Per mg | Note |
|---|---|---|---|---|
| Real Peptides | 50 mg | $129.60 | $2.59 | Sale price; list $259.20 |
| Real Peptides | 10 mg | $28.80 | $2.88 | Sale price; list $57.60; out of stock |
| CertaPeptides | 10 mg | $49.97 | $5.00 | Converted from euros |
Two vendors is a thin sample, so read the range as a snapshot, not a market price. Neither vendor appears in the Kovera table above under that name.
Is SS-31 legal?
| Question | Answer as of 12 October 2026 |
|---|---|
| FDA-approved? | Yes, as Forzinity (elamipretide, NDA 215244), accelerated approval 19 September 2025, for Barth syndrome in patients weighing at least 30 kg. A confirmatory trial is required. |
| Controlled substance? | No. DEA does not schedule it. |
| Can a pharmacy compound it? | Elamipretide is a component of an approved drug, so 503A rules on copies of approved drugs apply. It is not on the bulks list or the do-not-compound list. |
| Can a shop sell "research use only" vials? | It is the same molecule as an approved drug. FDA's August 2026 warning letter to Peptide Partners named its SS-31 listing as an unapproved new drug. |
| On the WADA 2026 prohibited list? | Not listed. |
Our peptide legality tool keeps the record for SS-31 and 43 other compounds, with sources. None of this is legal advice.
What doses are used in research?
As elamipretide, human trials have used subcutaneous dosing broadly in the ~4–40 mg/day range depending on indication. Preclinical work spans a wide dose range by model. Research vials are commonly 10–50 mg.
What does this guide cover?
For SS-31, vendor scrutiny centers on COA-verified identity and purity. It is a non-standard sequence (D-amino acids, dimethyltyrosine), so synthesis quality varies and mass-spec identity confirmation matters more than usual. Whether a published batch report can be checked against the issuing lab's own record is the signal we weight most heavily.
Is SS-31 in human clinical trials?
Yes, as elamipretide, and it has one approval. FDA granted accelerated approval to Forzinity (elamipretide) for Barth syndrome on 19 September 2025, with a confirmatory trial required. Registered trials as of 13 October 2026:
| Trial | Phase, size | Status |
|---|---|---|
| ReNEW, dry age-related macular degeneration (Stealth BioTherapeutics) | Phase 3, 313 | Active, not recruiting. Primary completion August 2027 |
| NCT07531251, Barth syndrome (Stealth) | Phase 4, 48 | Recruiting |
| NCT07275424, healthy aging and physical function (University of Washington) | Phase 2, 30 | Recruiting |
| NCT05168774, Friedreich's ataxia (Children's Hospital of Philadelphia) | Phase 1/2, 20 | Completed. Results posted December 2025 |
The healthy-aging trial is the first registered test of elamipretide for the use most research-vial buyers have in mind. It has not reported.
Related reading
What it's researched for
- mitochondrial dysfunction
- cellular aging
- cardiac and skeletal-muscle bioenergetics
Where to source it
ALL 4 VENDORS →RANKED BY COMPOSITE SCORE · PRICES ARE SNAPSHOTS FROM THE PRICE INDEX · PER-MG IS A WITHIN-COMPOUND COMPARATOR
Frequently asked about SS-31
What is SS-31?
SS-31 is a synthetic, cell-permeable tetrapeptide (D-Arg-dimethylTyr-Lys-Phe-NH2) that accumulates several-hundred-fold in the inner mitochondrial membrane and binds cardiolipin. It is studied as a mitochondrial-protective agent. The clinical-development name is elamipretide (also MTP-131, formerly Bendavia).
Is SS-31 the same as elamipretide?
Yes. SS-31, elamipretide, and MTP-131 are the same molecule. "SS-31" is the research designation; "elamipretide" is the clinical-development name used by Stealth BioTherapeutics. Bendavia was an earlier code name.
Is SS-31 FDA-approved?
Yes, for one indication. On 19 September 2025 FDA granted accelerated approval to elamipretide as Forzinity for Barth syndrome, a rare mitochondrial disease, in patients weighing at least 30 kg. A confirmatory trial is required. It is not approved for aging, mitochondrial myopathy, eye disease or any other use. Vendor-sold SS-31 is research-grade material, not the approved drug.
How pure is vendor-sold SS-31?
In our pooled, de-duplicated record of public lab results (mirrors to 2 August 2026), 37 SS-31 results from 26 clients had a median HPLC purity of 99.88%, lowest 98.81%. Of the 35 with a measured quantity, the median held 108.5% of the label amount and none held under 90%. One Kovera Labs report printed identity as "Unknown" and is counted as a fail.
How much does SS-31 cost per mg?
On 28 October 2026 our price index held three SS-31 listings from two vendors: $2.59 to $5.00 per mg. The low end is a 50 mg vial at a sale price; the high end is a 10 mg vial converted from euros. Prices change daily.
Is SS-31 legal to buy?
Elamipretide is a prescription drug, FDA-approved as Forzinity. It is not a controlled substance. A vial sold as an "SS-31 research peptide" is not the approved product, and FDA has treated such listings as unapproved drugs: its August 2026 warning letter to Peptide Partners named SS-31. Rules as of 12 October 2026; this is not legal advice.
How is SS-31 purity verified?
The same way as any research peptide: a per-batch Certificate of Analysis with HPLC purity and mass-spec identity. Run a vendor COA through our /tools/coa-verifier. Vendors selling SS-31 with no published per-batch COA are unverified.