What is the difference between SS-31 and elamipretide?

They are the same molecule. SS-31 is the original research designation (Szeto-Schiller peptide 31). Elamipretide is the generic pharmaceutical name adopted for clinical development. The compound has also been called Bendavia and MTP-131 at different stages of development. All four names refer to the same tetrapeptide: D-Arg-Dmt-Lys-Phe-NH2.

Is SS-31 FDA-approved?

No. As of this writing, SS-31 (elamipretide) is not FDA-approved for any indication. It has undergone multiple Phase II and Phase III clinical trials, and a New Drug Application was submitted for Barth syndrome. The FDA regulatory process is ongoing. The compound remains classified as an investigational drug.

How does SS-31 target mitochondria?

SS-31's alternating aromatic-cationic structure exploits the large negative membrane potential across the inner mitochondrial membrane, causing it to accumulate inside mitochondria at 1,000-5,000 fold higher concentrations than in the surrounding cell. Once there, it binds to cardiolipin, a phospholipid critical for electron transport chain organization and ATP production.

What conditions is SS-31 being studied for?

SS-31 has been studied in clinical trials for Barth syndrome (its lead indication), heart failure, primary mitochondrial myopathies, and age-related macular degeneration. Preclinical research has also explored its effects on aging, sarcopenia, kidney injury, and neurodegenerative conditions.

Can SS-31 reverse aging?

Preclinical data in aged animals shows that SS-31 can improve mitochondrial function, muscle performance, and cardiac function. However, 'reversing aging' is a substantial claim that has not been validated in human trials. SS-31 may improve specific aspects of mitochondrial dysfunction associated with aging, but it should not be expected to reverse the aging process broadly.

What are the side effects of SS-31?

In clinical trials, the most common side effects have been injection site reactions (10-25%), headache (5-15%), mild nausea (3-8%), and occasional fatigue. The overall safety profile has been described as generally favorable, with no major safety signals across multiple clinical trials. This is one of the most extensively characterized safety profiles among longevity peptides.

How is SS-31 different from NAD+ therapy?

They target different aspects of mitochondrial function. NAD+ provides the coenzyme substrate needed for electron transport chain reactions. SS-31 optimizes the structural organization of the electron transport chain itself by interacting with cardiolipin. They are complementary approaches — NAD+ supplies the fuel while SS-31 tunes the engine.

Mitochondrial Targeting SS-31's most distinctive property is its ability to concentrate inside mitochondria at 1,000-5,000 fold higher concentrations than in the surrounding cytoplasm. This selective accumulation is driven by the peptide's alternating aromatic-cationic motif (D-Arg and Lys provide positive charges; Dmt and Phe provide aromatic rings), which exploits the large negative membrane potential across the inner mitochondrial membrane. This targeting is critically important because it means SS-31 achieves effective concentrations at its site of action (the inner mitochondrial membrane) at systemic doses that would be far too low to have effects if the peptide distributed uniformly throughout the cell. The mitochondrial concentration effect is SS-31's key pharmacological advantage. How SS-31 Works: The Cardiolipin Connection What Is Cardiolipin?

Cardiolipin is a unique phospholipid found almost exclusively in the inner mitochondrial membrane. It has an unusual structure — four fatty acid chains instead of the typical two — that gives it distinctive biophysical properties essential for mitochondrial function. Cardiolipin plays critical roles in: Electron transport chain organization: Cardiolipin provides the structural scaffold for respiratory chain supercomplexes, the molecular assemblies that perform oxidative phosphorylation Cytochrome c anchoring: Cardiolipin holds cytochrome c at the inner mitochondrial membrane surface, keeping it available for electron transport and preventing its release (which triggers apoptosis) Cristae formation: Cardiolipin is essential for the folded cristae structure of the inner mitochondrial membran

Vendor Rankings

Independent rankings of peptide vendors based on aggregated lab data, COA transparency, community sentiment, and verified pricing. We publish everything — including the failures.

9+ samples tracked 27 vendors ranked 15 peptides tracked

All BPC-157 Tirzepatide Semaglutide CJC-1295 Ipamorelin GHK-Cu Retatrutide Tesamorelin

AGreat

B+Very Good

BGood

COkay

DPoor

EBad

FFraud

SS-31 Rankings

HUMAN TRIALS

9 samples across 27 vendors · Updated weekly from independent lab testing

#	Vendor	Avg score	Purity range	Tests	Verified $/mg	Grade	Profile
Grade A — Great
1	Retalux	9.2	—	4	—	A	review →
Grade B+ — Very Good
2	Reta-Peptide	8.7	—	4	—	B+	review →
Grade F — Fraud
3	Blessed Peptides	—	—	1	—	F	review →
4	Tech-Wave Peptides	—	—	0	—	F	review →
5	Unicorn Peptide	—	—	0	—	F	review →
6	Vector	—	—	0	—	F	review →
7	Xian Huawave Biotech	—	—	0	—	F	review →
8	Zhengzhou Lan Yun Cosmetic Trading	—	—	0	—	F	review →
9	SaiyanMed	—	—	0	—	F	review →
10	Arizen BioLabs	—	—	0	—	F	review →
11	Haikou Mingheng Technology	—	—	0	—	F	review →
12	Peptide Makers	—	—	0	—	F	review →
13	Liberty Peptides	—	—	0	—	F	review →
14	SPB	—	—	0	—	F	review →
15	Cellupep	—	—	0	—	F	review →
16	Certified Peptides	—	—	0	—	F	review →
17	Dankang BioHealth	—	—	0	—	F	review →
18	Heman Peptide HM	—	—	0	—	F	review →
19	Henan Sahe Peptide	—	—	0	—	F	review →
20	HkRoids	—	—	0	—	F	review →
21	Huaian Hanyou Peptide	—	—	0	—	F	review →
22	Learsi	—	—	0	—	F	review →
23	LiliPeptide	—	—	0	—	F	review →
24	Lisa Biopeptide	—	—	0	—	F	review →
25	Lumira	—	—	0	—	F	review →
26	Peptaion	—	—	0	—	F	review →
27	Peptide-S	—	—	0	—	F	review →
28	Allen Biotechnology Co ABC	—	—	0	—	F	review →

Verified $/mg = list price ÷ (avg tested qty / labeled qty). Vendors below the cutoff omitted from view.