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SS-31
Exploring the science of mitochondrial health, cellular energy, muscle function, and aging.
Ever wonder why some days you feel like you can accomplish everything, while other days even the simplest tasks seem to take twice the effort?
You wake up tired. Your afternoon energy disappears. Your muscles don’t recover the way they used to. And somewhere between work, responsibilities, and everyday life, you start wondering where all your energy went.
There’s a fascinating science behind how the body produces and manages energy.
And it begins inside our cells.
Meet the mitochondria, the microscopic structures that help power almost everything your body does.
From moving your muscles to supporting brain function, your cells depend on these tiny energy-producing systems.
One peptide that has attracted significant attention in mitochondrial research is SS-31, also known as elamipretide.
Unlike compounds that primarily influence hormones or neurotransmitters, SS-31 has been investigated for its direct interactions with the membranes inside mitochondria. Membrane research
And its scientific journey has become especially interesting.
What Exactly Is SS-31?
SS-31 is a synthetic peptide composed of four amino acids. It belongs to a class of compounds known as Szeto-Schiller peptides. Read the research
Its distinguishing characteristic is its ability to associate with the inner mitochondrial membrane.
Why does that matter?
Because the inner mitochondrial membrane contains much of the machinery responsible for producing ATP, the molecule your cells use as an immediate source of energy.
Researchers have investigated SS-31 for its interaction with a specialized membrane lipid called cardiolipin.
Cardiolipin helps maintain mitochondrial membrane structure and supports the organization of proteins involved in energy production. Cardiolipin and membranes
By interacting with this lipid-rich environment, SS-31 can influence mitochondrial structure and function in experimental systems.
This mechanism has made it an important subject in research involving mitochondrial disorders and cellular health.
Why Mitochondria Matter More Than You Think
Think of your body as a city that never sleeps.
Your heart keeps beating. Your brain processes information. Your muscles move. Your cells constantly carry out thousands of essential reactions.
All of this requires energy.
Mitochondria produce much of that energy through a process called oxidative phosphorylation.
But mitochondria do more than generate ATP.
They also participate in:
- Cellular metabolism: Helping convert nutrients into usable energy.
- Muscle function: Supporting the energy demands of movement.
- Cell signaling: Communicating information related to stress and cellular activity.
- Calcium regulation: Helping cells maintain important chemical balances.
- Cellular maintenance: Participating in processes that respond to damage and changing conditions.
Mitochondrial biology and aging review
Here’s where things become interesting.
As we age, mitochondrial function can change. Scientists have observed age-associated differences in mitochondrial efficiency, quality control, and the ability of cells to respond to metabolic stress. Research background
These changes are one reason mitochondrial biology has become a major focus of longevity research.
And SS-31 provides researchers with a way to investigate what happens when the mitochondrial membrane itself is targeted.
The Connection Between SS-31 and Cellular Energy
Most conversations about energy focus on getting more sleep, drinking coffee, or improving nutrition.
But there’s another important question:
How efficiently are our cells converting available fuel into energy?
Inside mitochondria, proteins arranged along the inner membrane work together to support ATP production.
The structure of that membrane is essential to the process.
In laboratory and animal studies, researchers have observed that SS-31 can interact with mitochondrial membranes and influence processes associated with cellular energy production. Membrane study · Experimental research review
Experimental findings have included changes in mitochondrial structure, responses to oxidative stress, and the behavior of proteins involved in energy metabolism.
It’s a different scientific approach from simply providing the body with more nutrients or stimulating hormone release.
Rather than acting as an energy source, SS-31 is being studied for how it interacts with the cellular structures involved in energy production.
That distinction is what makes its mechanism so interesting.
SS-31, Fatigue & Muscle Function: What Human Studies Found
Fatigue isn’t always about feeling sleepy.
For people with mitochondrial diseases, it can involve severe exercise intolerance, muscle weakness, and difficulty completing ordinary physical activities.
Researchers have investigated whether elamipretide could improve functional outcomes in people whose mitochondria are affected by genetic disorders.
An early clinical study
A randomized crossover trial published in 2020 studied elamipretide in adults with primary mitochondrial myopathy.
During the four-week treatment periods, researchers evaluated walking performance, fatigue, and patient-reported symptoms.
Although the primary walking-distance endpoint did not reach statistical significance, several secondary patient-reported measures showed improvements in fatigue and muscle-related symptoms. Read the crossover trial
Those findings encouraged additional research.
The larger Phase 3 study
In 2023, researchers published results from MMPOWER-3, a randomized clinical trial involving 218 participants with primary mitochondrial myopathy.
Participants received elamipretide or placebo for 24 weeks.
The study found no statistically significant advantage for elamipretide on its primary measures of walking distance and fatigue. Read MMPOWER-3
This was an important result because it showed that the encouraging findings from smaller studies did not necessarily translate into benefits in a larger population.
Together, these trials provide valuable information about mitochondrial disease research and the challenges of measuring changes in fatigue and physical performance.
A Major Milestone: FDA Approval in 2025
Here’s one of the most significant developments in the history of SS-31 research.
On September 19, 2025, the U.S. Food and Drug Administration granted accelerated approval to Forzinity (elamipretide). Read the announcement
It became the first FDA-approved treatment for improving muscle strength in adults and children weighing at least 30 kilograms who have Barth syndrome. Approved indication
Barth syndrome is a rare genetic condition that affects mitochondrial function and can cause serious heart problems, muscle weakness, and profound fatigue.
Its connection to cardiolipin makes it particularly relevant to elamipretide research.
What did the clinical evidence show?
The approval was supported by research involving 12 patients with Barth syndrome, including a randomized crossover trial and a long-term open-label extension.
The initial randomized portion did not show superiority over placebo on its primary walking-distance and fatigue measures.
However, researchers observed increases in knee extensor muscle strength during the longer open-label extension. FDA trial summary
The FDA granted accelerated approval based on this muscle-strength measure. Additional confirmatory research is required to verify clinical benefit. Accelerated-approval requirements
This approval represents an important milestone for mitochondrial medicine.
It also has a very specific scope: the approval applies to the prescription medicine Forzinity for Barth syndrome, not to all SS-31 research products or general energy and anti-aging applications.
Real People, Real Experiences: What Have Patients Reported?
One of the most compelling parts of mitochondrial research is hearing how people describe the impact of severe energy limitations on everyday life.
These are documented experiences involving people with Barth syndrome who received pharmaceutical elamipretide through clinical research or expanded access.
Christopher Pena: Rediscovering physical ability
In September 2025, the Mississippi Free Press reported on Christopher Pena, a 17-year-old living with Barth syndrome.
The condition had affected his ability to participate in school activities, exercise, and everyday physical tasks.
After receiving elamipretide through expanded access, Christopher described improvements in stamina.
One particularly memorable moment came when he was playing outside with his dog and realized he could jump, something he had previously struggled to do.
His experience illustrates how meaningful changes in physical function can be for someone living with a serious mitochondrial disorder.
Walker Burger: From exhausting walks to greater independence
Another account was published by The Atlanta Journal-Constitution in September 2025.
Walker Burger, an adult living with Barth syndrome, described growing up with severe fatigue and difficulty walking even relatively short distances.
After participating in elamipretide research, he reported substantial improvements in his physical capabilities.
He became an advocate for access to the medication, sharing how his experiences had changed during treatment.
What about experiences outside clinical trials?
SS-31 is also discussed in online communities interested in mitochondrial health, fatigue, and peptides.
Some individuals describe increased energy or improved daily functioning.
Others report no noticeable improvement, increased fatigue, or uncomfortable reactions. Read the community discussion
For example, one public discussion described an individual experiencing marked fatigue after starting SS-31, while commenters reported mixed experiences and the use of other products. Read the discussion
SS-31 and the Science of Aging
One reason mitochondrial research attracts so much attention is its connection to aging.
Over time, cells experience changes in metabolism, oxidative stress responses, and mitochondrial maintenance.
Researchers are interested in whether protecting or maintaining mitochondrial function could influence some of these biological processes.
SS-31 has been studied in experimental models involving:
- Age-related mitochondrial changes
- Scientists have examined whether SS-31 affects mitochondrial structure and function in aging tissues. Research background
- Oxidative stress
- Experimental studies have investigated its interactions with cellular processes associated with reactive oxygen species and mitochondrial damage. Research background
- Muscle function
- Research has explored how mitochondrial membrane activity relates to muscle performance and fatigue. Research background
- Cardiovascular biology
- Because heart muscle requires enormous amounts of energy, researchers have also investigated elamipretide in experimental models of cardiac and vascular dysfunction. Research background
- Neuroprotection
- Preclinical studies have examined whether mitochondrial-targeted peptides influence cellular responses to neurological stress. Research background
SS-31 vs. NAD+: What’s the Difference?
SS-31 and NAD+ are frequently mentioned together in discussions about cellular energy.
But they have very different biological roles.
NAD+
NAD+ is a naturally occurring coenzyme that participates in energy metabolism, cellular signaling, and numerous biochemical reactions. NAD+ review
SS-31
SS-31 is a synthetic peptide investigated for its interactions with the inner mitochondrial membrane and cardiolipin. Membrane research
An easy way to understand the difference:
NAD+ helps support the chemical reactions that cells use to transfer energy.
SS-31 is being studied for its interactions with the mitochondrial structures where many of those energy-producing reactions occur.
Both are relevant to mitochondrial biology, but their mechanisms are different.
Frequently Asked Questions
Is SS-31 the same as elamipretide?
Yes. SS-31 is a research name for the peptide also known as elamipretide. Research terminology
Does SS-31 increase cellular energy?
Laboratory and animal studies have demonstrated effects on mitochondrial function and energy-related pathways. Experimental research
Is SS-31 being studied for fatigue?
Yes. Human studies have investigated fatigue and exercise intolerance in people with primary mitochondrial disorders, with mixed results. Crossover trial · Phase 3 trial
Is SS-31 an anti-aging peptide?
SS-31 is frequently discussed in longevity research because of its interaction with mitochondrial biology. Aging research review
What is cardiolipin, and why is it important?
Cardiolipin is a specialized lipid concentrated in the inner mitochondrial membrane. It helps organize proteins and maintain membrane structures involved in energy production. Cardiolipin research
Is SS-31 FDA-approved?
A specific elamipretide prescription medicine, Forzinity, received accelerated FDA approval in September 2025 to improve muscle strength in eligible patients with Barth syndrome. Read the announcement
What about side effects?
Injection-site reactions, including redness, pain, itching, and hardening, were common in Forzinity clinical studies. Serious hypersensitivity is also a recognized concern. Prescribing information
The Bigger Picture
Energy is about more than how awake we feel.
Every movement, every thought, and every heartbeat depends on complex processes happening inside our cells.
Mitochondria play a central role in those processes, and scientists are continuing to discover how their structure and function influence human health.
SS-31 stands out because it takes mitochondrial research in a distinctive direction, focusing on the inner membrane and its relationship with cellular energy production.
From laboratory discoveries to human clinical trials and the development of an FDA-approved treatment for a rare mitochondrial disease, elamipretide has become an important part of modern mitochondrial research.
And perhaps the most fascinating part is that understanding how our cells produce energy may reveal entirely new ways to investigate human health, aging, and disease.
The story of mitochondrial science is still unfolding.
Scientific References
- U.S. Food and Drug Administration (2025). FDA Grants Accelerated Approval to First Treatment for Barth Syndrome. Read the announcement
- FDA Drug Trials Snapshots. Forzinity (elamipretide): Clinical Trial Results. Read the FDA summary
- Karaa A, et al. (2020). A Randomized Crossover Trial of Elamipretide in Adults With Primary Mitochondrial Myopathy. Journal of Cachexia, Sarcopenia and Muscle. Read the study
- Karaa A, et al. (2023). Efficacy and Safety of Elamipretide in Individuals With Primary Mitochondrial Myopathy: The MMPOWER-3 Randomized Clinical Trial. Neurology. Read the study
- The Mitochondria-Targeted Peptide SS-31 Binds Lipid Bilayers and Modulates Surface Electrostatics as a Key Component of Its Mechanism of Action (2020). Read the research
- National Library of Medicine. Forzinity (elamipretide) FDA Prescribing Information. Read the prescribing information
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For educational discussion only, not medical advice or a recommendation for self-experimentation. Meridian Research materials are for laboratory research use only.