SS-31 (Elamipretide) Research Guide: Mitochondria-Targeting Peptide and Cardioprotective Mechanisms

By Justin Cartier

SS-31, also called elamipretide, is a small peptide. It works deep inside the cell’s mitochondria. It sticks to a fat called cardiolipin and keeps it from breaking down.^[1] That matters for one reason. Cardiolipin holds the inner mitochondrial membrane in the tightly folded shape the cell needs to make energy, or ATP. When oxidative stress damages cardiolipin, those folds collapse and energy output drops. By shielding cardiolipin, SS-31 keeps the mitochondria running. And it’s one of the very few mitochondria-targeting peptides tested in real human trials, including heart failure.^[3]

Research-use note: SS-31 (elamipretide) is a research compound, not a medicine. Everything below is for laboratory research and education only, not human use.

Is elamipretide the same as SS-31?

Yes, they’re the same molecule wearing two names. SS-31 is the lab name, short for Szeto-Schiller peptide number 31. Elamipretide is the drug-development name used in clinical trials. The chemistry is D-Arg-Dmt-Lys-Phe-NH₂. Older names include MTP-131 and Bendavia. As a rule of thumb, heart-failure and kidney-injury studies say “elamipretide.” Basic mitochondria research says “SS-31.” It’s the same compound throughout.

That double naming can quietly wreck a literature search. Search PubMed for “SS-31” and you’ll miss every paper that says “elamipretide.” The reverse is just as true. So if you want a full picture of this compound, run both searches.

What SS-31 actually does in mitochondria

Its whole job is protecting cardiolipin. That fat is found almost nowhere except the inner mitochondrial membrane.^[1] Cardiolipin pins cytochrome c in place. It also keeps the electron transport chain neatly organized. Once oxidative stress or aging damages it, it can’t hold those groups together anymore. The membrane folds flatten out and energy metabolism stalls. The mitochondrion then starts leaking electrons instead of using them.

Here’s the clever part. SS-31 concentrates hard in the inner mitochondrial membrane, roughly 1,000 times more than in the rest of the cell. There it binds cardiolipin to shield it from that oxidative damage.^[1] Birk and colleagues, in the British Journal of Pharmacology, showed what that protection buys you. Guarding the cytochrome c and cardiolipin complex helps restore mitochondrial function and optimize ATP synthesis.^[1] Liu and colleagues, in the American Journal of Physiology, tested a related cardiolipin-protecting therapy. It guarded kidney mitochondria during low-blood-flow injury and cut the tissue damage that follows.^[2] It was an early nod toward its role in acute kidney injury research. Those effects came on too fast to be chalked up to anti-inflammation alone. They also tracked mitochondrial markers too closely for that.

Conditions where SS-31 shows preclinical signals

It shows early promise anywhere failing mitochondria are the core problem. Basically, any disease where the electron transport chain breaks down is a possible target. So is any disease where cardiolipin is damaged or ATP production drops. That list runs longer than you’d expect. Think heart failure with preserved ejection fraction (HFpEF, where human Phase 2 data now exists).^[4] Think low-blood-flow injury in the kidney, heart, or muscle. Think age-related muscle loss and the exercise intolerance that rides along with it. Add Alzheimer’s disease models, where its neuroprotective effects get studied, plus mitochondrial myopathies and heart damage from chemotherapy.

The pattern holds steady across all of them. SS-31 works best when the real problem is structural, meaning damaged cardiolipin and collapsed membrane folds. It works less well on a signaling or gene glitch. That makes sense. It binds a membrane part, not a receptor or an enzyme. So it can’t fix what it can’t physically reach. And in some models the benefit outlasts the treatment. That is probably because once the cardiolipin structure is rebuilt, the mitochondrion can hold its own shape again.

Human trial data: what elamipretide has shown in clinical settings

This is the part that sets it apart. Elamipretide has been tested in real human trials, which most mitochondria-targeting compounds never manage. Daubert and colleagues, in Circulation: Heart Failure, ran a randomized, placebo-controlled trial studying its effect on mitochondria and heart function.^[3] Butler and colleagues, in the Journal of Cardiac Failure, then looked at a Phase 2 trial in HFpEF, tracking its effect on left ventricular function.^[4] Barth syndrome is a rare genetic mitochondrial disease. There, Reid Thompson and colleagues, in Genetics in Medicine, reported a Phase 2/3 trial with gains in muscle strength and walking performance.^[5] None of these has led to full approval yet. But together they’re genuine human proof-of-concept in real disease, not just animal work.

Safety profile and side effects of SS-31 in research

Its safety record in animal studies is cleaner than you might guess. Rodent work at usual research doses hasn’t turned up liver, heart, or kidney toxicity. It dissolves in water and doesn’t stash itself in body fat. That keeps its behavior in the body simple and predictable. In the human heart-failure trials, the most common complaint was just a reaction at the injection site. No serious side effects got pinned on the compound itself.^[3][4] That said, human data still only covers a few patient groups. So it’s too early to assume broad safety.

How does SS-31 elamipretide compare to other peptides?

Among the mitochondria-targeting compounds, elamipretide has by far the most developed human pipeline. MitoQ (mitoquinone) is the leading small-molecule rival. But it’s an antioxidant that can flip to being pro-oxidant, and therefore damaging, at high doses. SkQ1 and its cousins sit in that same antioxidant class. On the peptide side, elamipretide is almost alone in clinical testing. Humanin, MOTS-c, and the SHLPs are still in earlier research without any late-stage programs behind them.

Dosing and administration in research

SS-31 can’t survive the gut, so it has to be given by injection, usually a subcutaneous shot. The human trials leaned on daily dosing over weeks. Research protocols have run it anywhere from roughly 1 to 40 mg per dose, depending on the model. Animal ischemia studies sometimes use an IV route instead. It arrives as a freeze-dried powder. You reconstitute it in sterile water or bacteriostatic water before use, and it keeps well refrigerated. None of these figures is a human dose recommendation, since there’s no approved use. They just describe how the research literature has handled the compound. Its water-soluble, non-accumulating profile is a big part of why the bioenergetics research on it has stayed so reproducible.

Consistency between lots is everything. So buy peptides in Canada where every batch is mass-spec verified.

Legal status and sourcing

SS-31 isn’t approved by Health Canada or the FDA as a finished drug. So research-grade elamipretide is sold as a research chemical for laboratory use only. The legal framework and supplier criteria for buying peptides in Canada spell out how that works.

Clean material is everything in mitochondrial research. So before you buy, put a few plain questions to the supplier. Does the Certificate of Analysis (COA) come from an independent third-party lab, not the seller’s own bench? Is it tied to the exact batch or lot you’ll receive, not a generic sample? Does it show the actual HPLC chromatogram with purity at 98 percent or higher? And does the mass spectrometry (MS) reading match SS-31’s expected mass of about 640 Da for this four-amino-acid peptide (D-Arg-Dmt-Lys-Phe-NH₂)? For any live-animal or cell work, also ask for endotoxin and sterility testing. A vendor that answers all of these clearly is the one worth trusting.

Reviv Peptides supplies SS-31 (elamipretide) with a third-party COA and HPLC purity confirmation. View the SS-31 10mg product page.

Clinical trials: ongoing and completed

The elamipretide program is the biggest mitochondrial peptide-drug effort in development today. The completed trials run wide. TAZPOWER covered Barth syndrome heart disease. SPIBA-201 added a Barth syndrome open-label extension. MMPOWER and MMPOWER-2 tested primary mitochondrial myopathy, with mixed results. ReCLAIM and ReCLAIM-2 looked at dry age-related macular degeneration. PROGRESS-HF studied heart failure with preserved ejection fraction.^[4][5] The kidney programs are still in earlier stages. Across all of these studies, more than 1,500 people have received elamipretide. That’s a big part of why the safety picture so far looks as favorable as it does.

SS-31 elamipretide questions

Is elamipretide the same as SS-31?

Yes. SS-31 is the research name and elamipretide is the clinical name. Both refer to the same four-amino-acid peptide (D-Arg-Dmt-Lys-Phe-NH₂). It has also been called MTP-131 and Bendavia.

What does SS-31 elamipretide do?

It enters cells and builds up in the inner mitochondrial membrane. There it binds cardiolipin to keep the membrane folds stable and protect energy production under oxidative stress.^[1] The action is structural, not chemical scavenging.

What are the benefits of elamipretide peptide?

In research it protects the mitochondrial membrane and lowers harmful reactive oxygen. It also restores ATP production under stress and reverses cardiolipin damage in low-blood-flow injury.^[1][2] Its human effects have been studied in heart failure and Barth syndrome.^[3][4][5]

Is SS-31 elamipretide FDA approved?

Not yet. A New Drug Application for Barth syndrome is under FDA review, with a decision expected around 2026. The other uses (mitochondrial myopathy, macular degeneration, heart failure) are still in earlier development.

What is the mechanism of action for SS-31 elamipretide?

It binds cardiolipin in the inner mitochondrial membrane.^[1] By holding cardiolipin in its bent shape, it props up the membrane folds. That stops cardiolipin damage and keeps the electron transport chain working.

Key data point: Daubert and colleagues (2017, Circulation: Heart Failure) ran a randomized, placebo-controlled trial of elamipretide as a mitochondria-targeting treatment in heart failure. It is one of the few published human datasets for a mitochondria-targeting peptide in a heart condition.^[3]

Summary

SS-31 (elamipretide) is the most clinically developed mitochondria-targeting peptide in research today. It binds cardiolipin to keep the inner mitochondrial membrane folds stable. It does not work by scavenging free radicals.^[1] Its program spans Barth syndrome, mitochondrial myopathy, macular degeneration, and heart failure, with human trial data already published.^[3][4][5] The safety record so far is favorable and the mechanism is well defined. If it clears approval for Barth syndrome, it would be the first approved mitochondria-targeting peptide drug. Research-grade material is legal in Canada and the United States for laboratory research only.

Further reading: Best peptides for anti-aging research.

Sources: [1] Targeting cardiolipin and the cytochrome c/cardiolipin complex to optimize ATP synthesis (Birk et al., 2014), PubMed. [2] Cardiolipin therapeutic protects mitochondria in renal ischemia (Liu et al., 2014), PubMed. [3] Randomized placebo-controlled trial of elamipretide in heart failure (Daubert et al., 2017), PubMed. [4] PROGRESS-HF Phase 2 trial of elamipretide in HFpEF (Butler et al., 2020), PubMed. [5] Phase 2/3 trial of elamipretide in Barth syndrome (Reid Thompson et al., 2021), PubMed.

Justin Cartier

The Reviv Peptides Research Team is a collective of science writers and researchers dedicated to producing evidence-based, peer-reviewed-grade content about research peptides. Our work focuses on molecular mechanisms, receptor pharmacology, and preclinical data — including GLP-1/GIP/glucagon incretin biology, growth hormone axis peptides (GHRH analogs and ghrelin-receptor secretagogues), mitochondrial-derived peptides (MOTS-c, SS-31), tissue-repair peptides (BPC-157, TB-500, GHK-Cu), and nootropic peptides (Semax, Selank). All content is written in a strict preclinical/laboratory context; none of our editorial material is intended as medical advice. Every guide is reviewed for scientific accuracy against published peer-reviewed literature.