What it is
SS-31 is a synthetic peptide — a short chain of just four amino acids made in a lab. Its technical name is elamipretide, and it is also known as Bendavia and MTP-131. The name stands for Szeto-Schiller peptide 31, after Dr. Hazel Szeto at Weill Cornell Medical College and Dr. Peter Schiller at the Montreal Clinical Research Institute, who developed it.
On September 19, 2025, elamipretide received accelerated approval from the FDA under the brand name Forzinity for Barth syndrome, a very rare genetic disorder affecting about 150 people in the United States. That made it the first FDA-approved treatment that specifically targets mitochondria.
Mitochondria are the tiny structures inside your cells that make ATP, the molecule your cells actually spend as energy. SS-31 heads straight for the inner wall of the mitochondria and concentrates there rather than spreading through the cell. Once there it acts as an antioxidant — it neutralises free radicals, the unstable molecules that damage cells — and it protects the structure that produces energy.
A useful way to think about it: NAD+ is fuel, MOTS-C is a supercharger, and SS-31 is the mechanic. It fixes the cracks and leaks in the engine. Putting fuel and upgrades into a damaged engine gives limited results, so for people over 35 to 40 starting out, the advice is to repair first with SS-31.
It is injected under the skin — that is what subcutaneous means.
SS-31 (elamipretide, Bendavia, MTP-131) is a synthetic tetrapeptide of the Szeto-Schiller class, developed by Hazel Szeto (Weill Cornell Medical College) and Peter Schiller (Montreal Clinical Research Institute). It received FDA accelerated approval on September 19, 2025 as Forzinity for Barth syndrome, a genetic disorder affecting about 150 people in the United States — the first mitochondria-targeted therapeutic, and the first mitochondria-targeted peptide, approved for any indication.
Its defining property is selective accumulation in the inner mitochondrial membrane, independent of membrane potential, reaching concentrations 5000 times higher than the surrounding cytoplasm within 15 minutes of administration. The positively charged peptide is electrostatically drawn to cardiolipin, the negatively charged phospholipid unique to that membrane, where it stabilises cristae architecture and the supercomplex organisation of the electron transport chain.
The functional consequences described are mitigation of oxidative stress at the point of generation, suppression of inflammation including neuroinflammation, maintenance of mitochondrial health, and prevention of apoptosis — advantages over natural antioxidants that stem from compartmental targeting rather than downstream cytosolic scavenging.
The conceptual division against neighbouring compounds: NAD+ supplies substrate, MOTS-C activates pathways, SS-31 repairs the structural damage that limits both. The clinical programme sits in Barth syndrome, primary mitochondrial myopathy, and heart failure with preserved ejection fraction, with 18 human trials across conditions.
Subcutaneous administration, daily. Earlier guidance specified fasted morning dosing on an 8–12 week cycle with protocols tied to vial size on cost grounds; current guidance for age-related decline is 1 to 2 mg daily for 4 to 8 weeks with no fasting or timing constraint.
How it works
Your mitochondria are the power plants inside your cells. They turn food into ATP, the energy your body uses for everything from moving muscles to thinking to repairing tissue. Your body stores almost no ATP — about 100 grams at any moment, enough for a few seconds of hard effort — so it has to remake it constantly. A moderately active person cycles through their whole body weight in ATP every day.
About 90% of that ATP is made on the inner wall of the mitochondria by a line of protein machines that pass electrons from one to the next, like a bucket brigade. When it runs smoothly you get lots of energy and little waste. But electrons can leak out. When they do, they react with oxygen and form free radicals, unstable molecules that damage cells. As you age, more electrons leak and more damage builds up.
The key part holding the whole line together is a fat molecule called cardiolipin. It only exists in the inner wall of mitochondria. It props up the folds (called cristae) that give more surface area to make energy, keeps the protein machines lined up, and helps electrons move efficiently. Free radicals attack cardiolipin specifically. Damaged cardiolipin means machines fall out of line, more electrons leak, more free radicals form, and more cardiolipin is damaged. That is a vicious cycle, and the result is less energy and more damage over time.
SS-31 has a positive charge and cardiolipin has a negative one, so SS-31 is pulled to it like a magnet. It reaches the mitochondria within 15 minutes and concentrates there at 5000 times the level in the rest of the cell. Once bound, it shields cardiolipin, keeps the machines lined up, and preserves the folds. Studies show 40 to 60% less free radical production.
Ordinary antioxidants are like street sweepers cleaning up pollution after it is in the air. SS-31 fixes the leak that causes the pollution in the first place.
Roughly 90% of cellular ATP is generated by oxidative phosphorylation on the inner mitochondrial membrane. Electrons pass along the respiratory complexes of the electron transport chain, driving proton translocation and the electrochemical gradient that powers ATP synthase. The body holds only about 100 grams of ATP at any time; a moderately active person turns over their body weight in ATP daily, so throughput efficiency is everything.
Electron leakage from the chain reacts with oxygen to form reactive oxygen species. With ageing, leakage increases and ROS preferentially oxidise cardiolipin, the dimeric phospholipid confined to the inner membrane. Cardiolipin performs three structural roles: it supports cristae architecture, it organises the respiratory complexes into supercomplexes that minimise electron leakage, and it stabilises the cardiolipin–cytochrome c interaction that governs electron transfer efficiency. Oxidised cardiolipin causes supercomplex disassembly, more leakage, more ROS, and further cardiolipin peroxidation — a self-amplifying loop that lowers ATP output and raises oxidative stress.
SS-31 is cationic; cardiolipin is anionic. The electrostatic attraction drives accumulation in the inner membrane at 5000 times cytoplasmic concentration within 15 minutes, independent of membrane potential. Bound to cardiolipin, SS-31 stabilises membrane structure, protects cardiolipin from peroxidation, maintains supercomplex organisation, and preserves cristae. The reported outcome is improved electron transfer, a 40 to 60% reduction in ROS generation, higher ATP production, and preserved mitochondrial morphology.
The mechanistic distinction from conventional antioxidants is upstream action: SS-31 reduces ROS formation at the membrane rather than scavenging ROS after release. By contrast, MOTS-C reduces ROS at the nuclear level via AMPK, PGC-1 alpha, and NRF2-driven antioxidant enzyme expression (Gudiksen and colleagues, 2026) — non-overlapping mechanisms. Preclinical data also suggest MOTS-C may support cardiolipin biosynthesis through AMPK activation.
Pharmacokinetics: peak plasma within 15 minutes of subcutaneous dosing, half-life about 2 hours, 100% renal clearance with no hepatic metabolism, and mitochondrial retention well beyond plasma exposure.
What it does
The headline is energy. SS-31 has been called the most potent energy-boosting peptide available, but it does not work like a stimulant. It repairs the structures that make energy, so existing mitochondria work better. It does not make more mitochondria — it is about quality, not quantity.
In old mice (equivalent to humans in their late 70s), 8 weeks of SS-31 improved the shape of the mitochondria, restored their internal folds, and reduced signs of cellular ageing in kidney, heart, and muscle tissue. In people with Barth syndrome, walking distance in a 6 minute test improved by 96 metres.
It cuts free radical production at the source by 40 to 60%. It protects the heart, kidneys, brain, and muscles, all of which depend heavily on mitochondria. In aged mice it reduced frailty and partly reversed age-related decline in heart function and muscle fatigue.
Earlier descriptions also list it as anti-ageing, anti-inflammatory (including inflammation in the brain), supportive of memory and thinking, antifibrotic (working against scar tissue build-up in organs), beneficial in kidney disease through a cellular energy sensor called AMPK, and helpful against insulin resistance, when the body stops responding properly to its own insulin.
Human trials in heart failure and mitochondrial myopathy showed mixed results: some measures improved, but the main goals were not consistently met.
The primary framing is bioenergetic restoration rather than stimulation. SS-31 raises ATP output from existing mitochondria by stabilising the electron transport chain and reducing leakage; it does not increase mitochondrial number. In aged mice (late-70s human equivalent), 8 weeks of treatment improved mitochondrial morphology, restored cristae structure, and reduced senescence markers (p16, senescence-associated beta-galactosidase) in glomerular cells, cardiac tissue, and skeletal muscle (Sweetwyne and colleagues, 2017, Kidney International).
Clinically, the TAZPOWER 168-week open-label extension (Genetics in Medicine, 2024) in Barth syndrome reported a 96.1 metre improvement in 6 Minute Walk Test (P = .003), over 45% improvement in leg muscle strength, 45% improvement in heart function, a 2.1 point improvement in the Barth Syndrome Symptom Assessment, improved 3D left ventricular volumes, and improved cardiolipin levels versus baseline.
ROS generation falls 40 to 60% with cardiolipin stabilisation. Organ protection is documented across heart, kidney, brain, and skeletal muscle. In aged C57BL/6J mice, 8 weeks of elamipretide mitigated frailty accumulation and partially reversed age-related declines in cardiac strain and skeletal muscle fatigue resistance, with pathway analysis showing upregulation of fatty acid metabolism, mitochondrial translation, and oxidative phosphorylation genes alongside reduced inflammation markers — without detectable change in epigenetic or transcriptomic age (Mitchell, Pharaoh and colleagues, 2025, Aging Cell). Siegel and colleagues (2019) showed reversal of age-related exercise intolerance, increased muscle mass and endurance, and improved kidney function in aged mice.
Earlier descriptions add anti-ageing, anti-inflammatory and anti-neuroinflammatory activity, cognitive and memory support, antifibrotic activity, kidney benefit via AMPK activation, and improvement in insulin resistance, with a disease list spanning cardiovascular, neurodegenerative, airway, retinal, oncological, and genetic neuromuscular conditions. Human trials in HFpEF and primary mitochondrial myopathy produced mixed results: some secondary endpoints improved, primary endpoints were not consistently met.
Benefits
Evidence grades: what the labels mean
- Human trials Supported by randomised or placebo-controlled human trials.
- Limited human data Some human evidence, such as pilot studies, case reports or observational data, but no controlled trials.
- Animal or lab only Shown in animal or cell studies only; not yet tested in people.
- Anecdotal No published studies; based on user reports or theory.
Each grade reflects the strongest published support for that specific claim, not for the compound as a whole.
- Mitochondrial repair — restores the structure of damaged mitochondria so existing ones work better (quality, not quantity).Animal or lab only
- Increased energy — described as the most potent energy-boosting peptide available; Barth syndrome patients walked 96 metres further in a 6 minute test.Limited human data
- Neutralises free radicals (unstable molecules that damage cells) at the source, cutting their production by 40 to 60%, and reverses oxidative stress damage.Animal or lab only
- Protects the heart, kidneys, brain, and muscles.Animal or lab only
- Reduced frailty and partly reversed age-related decline in heart function and muscle fatigue in aged mice.Animal or lab only
- Anti-ageing.Animal or lab only
- Anti-inflammatory, including inflammation in the brain.Animal or lab only
- Supports memory and thinking.Animal or lab only
- Antifibrotic — works against the build-up of scar tissue in organs.Animal or lab only
- Beneficial for kidney disease, by activating AMPK, a sensor inside cells that switches on when energy runs low.Animal or lab only
- Fights insulin resistance, which is when the body stops responding properly to its own insulin.Animal or lab only
- May prevent or reduce the symptoms of cardiovascular disease.Limited human data
- May prevent or reduce the symptoms of neurodegenerative conditions — diseases in which nerve cells progressively break down.Animal or lab only
- May prevent or reduce the symptoms of asthma and COPD (chronic obstructive pulmonary disease, a long-term lung condition).Animal or lab only
- May prevent or reduce the symptoms of age-related macular degeneration, an eye disease affecting central vision.Limited human data
- May prevent or reduce the symptoms of cancer.Animal or lab only
- FDA-approved for Barth syndrome, a rare inherited condition affecting the heart and muscles.Human trials
- May prevent or reduce the symptoms of primary mitochondrial myopathy, a muscle disease caused by faulty mitochondria.Limited human data
- May prevent or reduce the symptoms of Duchenne muscular dystrophy, an inherited muscle-wasting disease.Animal or lab only
- May prevent or reduce the symptoms of Friedreich's ataxia, an inherited disorder affecting movement and coordination.Animal or lab only
- Mitochondrial repair — restored cristae structure and morphology and reduced senescence markers in kidney, cardiac, and skeletal muscle tissue of aged mice after 8 weeks; improves existing mitochondria rather than increasing their number.Animal or lab only
- Increased energy — described as the most potent energy-boosting peptide available; 96 metre improvement in 6 Minute Walk Test in Barth syndrome.Limited human data
- Reduced oxidative stress — 40 to 60% reduction in mitochondrial ROS production at the source via cardiolipin stabilisation, plus reversal of oxidative-stress damage.Animal or lab only
- Organ protection across heart, kidney, brain, and skeletal muscle.Animal or lab only
- Functional improvement in ageing — mitigated frailty and partially reversed cardiac strain and skeletal muscle fatigue declines in aged mice, with pro-longevity pathway shifts.Animal or lab only
- Anti-ageing.Animal or lab only
- Anti-inflammatory, including neuroinflammation.Animal or lab only
- Memory and cognitive support.Animal or lab only
- Antifibrotic.Animal or lab only
- Benefit in kidney disease via AMPK pathway activation.Animal or lab only
- Improvement in insulin resistance.Animal or lab only
- May prevent or mitigate cardiovascular disease.Limited human data
- May prevent or mitigate neurodegenerative conditions.Animal or lab only
- May prevent or mitigate asthma and COPD.Animal or lab only
- May prevent or mitigate age-related macular degeneration.Limited human data
- May prevent or mitigate cancer.Animal or lab only
- FDA-approved (Forzinity, 2025) for Barth syndrome.Human trials
- May prevent or mitigate primary mitochondrial myopathy.Limited human data
- May prevent or mitigate Duchenne muscular dystrophy.Animal or lab only
- May prevent or mitigate Friedreich's ataxia.Animal or lab only
What to expect
SS-31 gets into your blood fast — peak levels within 15 minutes — and leaves the blood in about 2 hours. But it collects inside your mitochondria and stays there much longer than blood levels suggest.
Most people start to notice changes within the first 1 to 2 weeks, usually subtle improvements in energy and recovery. The full repair phase plays out over 4 to 8 weeks. Users describe the energy as steady and sustained rather than a stimulant-like buzz. Some users are frustrated that the effect is not dramatic; that fits a compound that repairs structure rather than giving a quick boost. The benefits are often described as "things working better" rather than a distinct feeling. Some users report a few days of tiredness at the start before things improve.
The most common thing you will notice is a reaction where you inject: redness, itching, and sometimes a welt. Rotate your injection sites. Antihistamines or hydrocortisone cream help, and users report reactions fade over time.
SS-31 makes most sense if you are over 35 to 40 with falling energy, slow recovery, and metabolic issues. By your 40s you may have 10 to 20 years of built-up damage, and damaged mitochondria cannot respond well to other compounds. That is why some people take NAD+ and feel nothing. Younger, healthy people may not need SS-31 at all.
Users who run SS-31 first and then MOTS-C often report getting more out of MOTS-C and NAD+ afterwards.
None of this replaces the basics. Training, food, and sleep stay your main focus. Without them, any peptide is a plaster on a problem you keep creating.
Peak plasma concentration is reached within 15 minutes of subcutaneous administration, with a plasma half-life of about 2 hours; mitochondrial accumulation outlasts plasma exposure considerably, so blood levels understate tissue residence.
Onset of perceptible effect is typically 1 to 2 weeks — subtle gains in baseline energy and training recovery — with the repair phase completing over 4 to 8 weeks. Users characterise the effect as stable, sustained energy rather than an acute stimulant response, and a proportion report the effect as under-dramatic; this is consistent with structural repair rather than pathway activation. A subset report transient fatigue in the first few days that resolves as treatment continues.
Injection-site reactions dominate the tolerability picture in both trials and practice: erythema (57%), pruritus (47%), pain (20%), urticaria (20%), irritation (10%). They are attributed to a mild local histamine response, are generally mild, diminish with continued use, and respond to site rotation, antihistamines, or hydrocortisone cream.
The target population is adults over 35 to 40 with energy decline, slow recovery, and metabolic dysfunction — by the 40s, 10 to 20 years of accumulated mitochondrial damage is plausible. Damaged mitochondria respond poorly to optimisation signals, which is offered as the explanation for null subjective response to NAD+: conversion of NAD+ precursors requires ATP that compromised mitochondria cannot supply. In younger, metabolically healthy individuals SS-31 may be unnecessary. Barth syndrome patients have cardiolipin damage from a genetic defect; older adults have it from decades of oxidative and inflammatory stress — different cause, same downstream lesion.
Users who sequence SS-31 before MOTS-C frequently report greater benefit from MOTS-C and NAD+ afterwards. The compound is an adjunct to training, nutrition, and sleep, not a substitute.
Reconstitution and dosing
The practical protocol for age-related decline is simple: 1 to 2 mg once a day, injected under the skin, for 4 to 8 weeks. You do not need to fast, and there is no set time of day. Older guidance had you dose in the morning, fasted, on an 8 to 12 week cycle with different protocols for different vial sizes; the current approach drops those constraints.
Reconstitute a 10 mg vial with 2 mL of bacteriostatic water. On an insulin syringe (100 units is 1 mL), 10 units gives 500 mcg and 20 units gives 1 mg.
The usual sequence is repair first, then optimise. Weeks 1 through 4 (or up to 8): SS-31 at 1 to 2 mg daily plus NAD+ at 100 mg under the skin three times a week. Weeks 5 through 12: swap SS-31 for MOTS-C at 10 mg split into three injections a week (Monday, Wednesday, Friday), keeping NAD+ at 100 mg three times a week. After the 12 week cycle, take 4 to 8 weeks fully off. You can repeat this 2 to 3 times a year.
If you are younger or healthier, a prevention-first version starts with MOTS-C and NAD+ alone, then adds SS-31 at 1 to 2 mg daily for 4 to 8 weeks only if fatigue, poor recovery, or metabolic issues are still present at weeks 4 through 8.
You will see much higher doses online — 5 mg, 10 mg, even 50 mg a day. The Barth syndrome trials used 40 mg daily. Those doses are for people with a genetic disease and fundamentally broken mitochondria. Age-related damage responds to the lower dose. Mouse studies translate to roughly 5 to 7 mg daily in humans, but the practical protocol stays at 1 to 2 mg.
Practical protocol (age-related decline): 1 to 2 mg subcutaneously once daily for 4 to 8 weeks. No fasting requirement and no timing constraint. This supersedes earlier guidance that specified fasted morning dosing, 8–12 week cycles with 4–8 week washout, and vial-size-specific low-dose, standard (5 mg), and maximum protocols, including a 10–14 day 1 mg MOTS-C priming course.
Reconstitution: 10 mg vial with 2 mL bacteriostatic water gives 5 mg/mL; 10 units = 500 mcg, 20 units = 1 mg on a U-100 insulin syringe.
Repair-first sequencing (ages 35 to 55 with declining energy, recovery, and metabolic markers): weeks 1 through 4 (or up to 8), SS-31 1 to 2 mg daily with NAD+ 100 mg subcutaneously three times weekly. Weeks 5 through 12, replace SS-31 with MOTS-C 10 mg split across three injections weekly (Monday, Wednesday, Friday), continuing NAD+ at 100 mg three times weekly. Then 4 to 8 weeks completely off; the cycle can be repeated 2 to 3 times per year.
Prevention-first (younger or healthier): MOTS-C 10 mg split three times weekly plus NAD+ 100 mg three times weekly from the start; reassess at weeks 4 through 8 and add SS-31 1 to 2 mg daily for 4 to 8 weeks only if fatigue, poor recovery, or metabolic issues persist.
Concurrent use: following Gudiksen and colleagues (2026), concurrent SS-31 and MOTS-C from day one is a supported option for moderate age-related decline in otherwise active individuals, given non-overlapping ROS-reduction mechanisms. Significant dysfunction still warrants SS-31 alone for 4 to 8 weeks before adding MOTS-C.
Higher doses: TAZPOWER used 40 mg daily in Barth syndrome; online protocols of 5 mg, 10 mg, or 50 mg per day derive from systemic mitochondrial disease contexts. Mouse doses translate to roughly 5 to 7 mg daily in humans. For accumulated rather than genetic damage, 1 to 2 mg is the working range.
Clearance: 100% renal, no hepatic metabolism — relevant to dose selection in any degree of kidney impairment.
Standard, 10 mg vial
Mix with 2 mL (200 units) of bacteriostatic water.
5 mg/mL · 50 mcg per unit
Cycle: 4 to 8 weeks (repair phase), then typically transition to MOTS-C and NAD+; 4 to 8 weeks off after a 12 week cycle · Frequency: Once daily; subcutaneous; no fasting or timing constraint
| When | Dose | Draw | How often |
|---|---|---|---|
| Starting | 1 mg | 20 units | 1×/day |
| Full | 2 mg | 40 units | 1×/day |
Alternative protocols
Alternative protocols reflect older community practice and are kept for reference.
Alternative, 10 mg vial — MOTS-C priming protocol only
Mix with 1 mL (100 units) of bacteriostatic water.
10 mg/mL · 100 mcg per unit
Cycle: 10–14 days, run immediately before a MOTS-C cycle · Frequency: Once per day; morning, at a consistent time; fasted; subcutaneous
| When | Dose | Draw | How often |
|---|---|---|---|
| 10–14 days prior to the start of a MOTS-C cycle | 1 mg | 10 units | 1×/day |
Alternative, 30 mg vial — low dose protocol
Mix with 2 mL (200 units) of bacteriostatic water.
15 mg/mL · 150 mcg per unit
Cycle: 8–12 week cycle followed by a 4–8 week washout · Frequency: Morning, at a consistent time; fasted; subcutaneous. Dosing days drop from 5 to 3 per week from week 6
| When | Dose | Draw | How often |
|---|---|---|---|
| Week 1 (1 mg) | 1 mg | 6.67 units | 1×/day, 5 days/week |
| Weeks 2–5 (2 mg) | 2 mg | 13.33 units | 1×/day, 5 days/week |
| Weeks 6–8 (3 mg) | 3 mg | 20 units | 1×/day, 3 days/week |
| Weeks 9–12 (4 mg) | 4 mg | 26.67 units | 1×/day, 3 days/week |
Alternative, 30 mg vial — standard protocol
Mix with 2 mL (200 units) of bacteriostatic water.
15 mg/mL · 150 mcg per unit
Cycle: 8–12 weeks · Frequency: 3–7 days per week; morning, at a consistent time; fasted; subcutaneous
| When | Dose | Draw | How often |
|---|---|---|---|
| Whole cycle (5 mg) | 5 mg | 33.33 units | 3–7 days per week |
Alternative, 30 mg vial — maximum protocol
Mix with 2 mL (200 units) of bacteriostatic water.
15 mg/mL · 150 mcg per unit
Cycle: 8–12 week cycle followed by a 4–8 week washout · Frequency: Morning, at a consistent time; fasted; subcutaneous. Dosing days drop from 5 to 3 per week from week 6
| When | Dose | Draw | How often |
|---|---|---|---|
| Week 1 (1.5 mg) | 1.5 mg | 10 units | 1×/day, 5 days/week |
| Weeks 2–5 (3 mg) | 3 mg | 20 units | 1×/day, 5 days/week |
| Weeks 6–8 (4.5 mg) | 4.5 mg | 30 units | 1×/day, 3 days/week |
| Weeks 9–12 (6 mg) | 6 mg | 40 units | 1×/day, 3 days/week |
Alternative, 50 mg vial — low dose protocol
Mix with 3 mL (300 units) of bacteriostatic water.
16.67 mg/mL · 166.67 mcg per unit
Cycle: 8–12 week cycle followed by a 4–8 week washout · Frequency: Morning, at a consistent time; fasted; subcutaneous. Dosing days drop from 5 to 3 per week from week 6
| When | Dose | Draw | How often |
|---|---|---|---|
| Week 1 (1 mg) | 1 mg | 6 units | 1×/day, 5 days/week |
| Weeks 2–5 (2 mg) | 2 mg | 12 units | 1×/day, 5 days/week |
| Weeks 6–8 (3 mg) | 3 mg | 18 units | 1×/day, 3 days/week |
| Weeks 9–12 (4 mg) | 4 mg | 24 units | 1×/day, 3 days/week |
Alternative, 50 mg vial — standard protocol
Mix with 3 mL (300 units) of bacteriostatic water.
16.67 mg/mL · 166.67 mcg per unit
Cycle: 8–12 weeks · Frequency: 3–7 days per week; morning, at a consistent time; fasted; subcutaneous
| When | Dose | Draw | How often |
|---|---|---|---|
| Whole cycle (5 mg) | 5 mg | 30 units | 3–7 days per week |
Alternative, 50 mg vial — maximum protocol
Mix with 3 mL (300 units) of bacteriostatic water.
16.67 mg/mL · 166.67 mcg per unit
Cycle: 8–12 week cycle followed by a 4–8 week washout · Frequency: Morning, at a consistent time; fasted; subcutaneous. Dosing days drop from 5 to 3 per week from week 6
| When | Dose | Draw | How often |
|---|---|---|---|
| Week 1 (1.5 mg) | 1.5 mg | 9 units | 1×/day, 5 days/week |
| Weeks 2–5 (3 mg) | 3 mg | 18 units | 1×/day, 5 days/week |
| Weeks 6–8 (4.5 mg) | 4.5 mg | 27 units | 1×/day, 3 days/week |
| Weeks 9–12 (6 mg) | 6 mg | 36 units | 1×/day, 3 days/week |
10 mg in 2 mL is 5 mg/mL, or 50 mcg per unit. Draw 20 units (0.2 mL) for 1000 mcg.
Who should avoid it
- Anyone pregnant or breastfeeding. There is not enough safety data.
- Anyone with severe kidney disease. SS-31 leaves the body entirely through the kidneys, so if they are not working well the peptide can build up.
- Anyone who is hypersensitive to mitochondria-targeted compounds or to the peptide's components — meaning anyone who has reacted badly to a compound of this type before.
- Talk to a doctor before starting, and go through your full medication list with them.
- Use caution and speak to a doctor first if you have mild to moderate kidney impairment.
- Use caution if you take medicines that affect how mitochondria work.
- Use caution if you have an autoimmune condition. Supporting mitochondria may change how immune cells behave.
- Use caution if you have a heart condition. Some trials showed variable effects on the heart, so check with a physician.
- No well-established drug interactions are known, but combining SS-31 with other mitochondria-targeting compounds should be monitored.
- Pregnancy or breastfeeding (insufficient safety data).
- Severe kidney disease. SS-31 is 100% renally cleared with no hepatic metabolism, so impaired renal function means impaired clearance.
- Hypersensitivity to mitochondria-targeted compounds or known hypersensitivity to the peptide components.
- Consult a physician before starting and review the full medication list.
- Caution: mild to moderate renal impairment — physician consultation advised given complete renal excretion.
- Caution: concurrent medications affecting mitochondrial function.
- Caution: autoimmune conditions — mitochondrial support may alter immune cell function.
- Caution: cardiac conditions — some trials in heart failure with preserved ejection fraction showed variable cardiac effects and inconsistent primary endpoints.
- Drug interactions: none well established. Theoretically, combination with other mitochondria-targeting compounds should be monitored.
- Note the brevity of the hard contraindications relative to the breadth of claimed activity. No screening for hepatic or oncological status has been established.
Side effects
- Irritation where you inject — redness, swelling, itching, pain, hives, or welts. This is by far the most common problem. In trials, redness affected 57% of people, itching 47%, pain 20%, hives 20%, and irritation 10%. Most cases are mild and go away on their own. Rotating injection sites helps, and users manage flare-ups with antihistamines or hydrocortisone cream.
- Headache, reported in some trials.
- Tiredness. Some users feel more tired in the first few days before things improve.
- Stomach upset or gas, described as rare.
- Dizziness.
- Signs of an allergic reaction: a fast or erratic heartbeat; heavy sweating; shortness of breath; confusion; severe weakness; loss of coordination; stiff muscles with a high fever; and eye symptoms including blurred vision, tunnel vision, eye pain, swelling of the eyes, and seeing halos around lights. These are emergency signs — stop and seek medical help.
- The overall safety record is good. Across all trials, including over 3 years of daily use in Barth syndrome patients, no serious drug-related adverse events have been consistently reported.
- Injection-site reactions, the dominant adverse event across all clinical trials: erythema 57%, pruritus 47%, injection-site pain 20%, urticaria 20%, irritation 10%. Attributed to mild local histamine release. Most resolve without intervention; site rotation, antihistamines, or topical hydrocortisone are used in practice.
- Headache (reported in some trials).
- Fatigue — paradoxically, initial fatigue in the first few days that resolves as the repair phase progresses.
- Gastrointestinal discomfort (rare); flatulence.
- Dizziness.
- Allergic-reaction signs: tachyarrhythmia, profuse sweating, dyspnoea, confusion, severe weakness, loss of coordination, muscle rigidity with high fever, and ocular symptoms — blurred vision, tunnel vision, eye pain, periorbital swelling, halos around lights. The rigidity-hyperthermia-confusion cluster overlaps with serotonin syndrome and neuroleptic malignant syndrome presentations, though that overlap has not been formally addressed.
- Safety profile is strong overall: across over 3 years of daily use in Barth syndrome patients, no serious drug-related adverse events have been consistently reported. Elamipretide received FDA accelerated approval as Forzinity on September 19, 2025.
What the evidence shows
SS-31 has more human data than any other mitochondria-targeted peptide. It has been tested in 18 human clinical trials, and on September 19, 2025 it was approved by the FDA under the name Forzinity for Barth syndrome, a very rare genetic disorder affecting about 150 people in the United States.
The key human trial is TAZPOWER. It gave 40 mg a day by injection under the skin to 12 patients with Barth syndrome. The first 12-week part did not meet its main goals, but the long 168-week follow-up (Genetics in Medicine, 2024) did show sustained gains: patients walked 96.1 metres further in a 6 Minute Walk Test, leg strength improved by over 45%, heart function improved by 45%, and a symptom score improved by 2.1 points. Ten patients entered the extension and 8 reached the week 168 visit. The most common side effects were injection-site reactions.
Other human trials, in heart failure and mitochondrial myopathy, gave mixed results. Some measures improved, but the main goals were not consistently met.
In animals the picture is stronger. In very old mice (equivalent to humans aged 70 to 90), 8 weeks of SS-31 reversed the age-related drop in energy production and improved kidney structure (Sweetwyne and colleagues, Kidney International, 2017). A 2025 study in Aging Cell (Mitchell, Pharaoh and colleagues) found 8 weeks of treatment reduced frailty and partly reversed age-related heart and muscle decline. Other mouse studies improved exercise tolerance, endurance, and heart mitochondria structure.
What this means for you: the human proof is in a rare genetic disease at 40 mg a day. The evidence for healthy ageing adults at 1 to 2 mg a day comes from mouse studies, not human trials.
SS-31 (elamipretide) has the broadest evidence base of any mitochondria-targeted peptide: 18 human clinical trials and FDA accelerated approval on September 19, 2025 as Forzinity for Barth syndrome, making it the first mitochondria-targeted peptide approved for any indication.
TAZPOWER (Phase 2/3) tested 40 mg daily subcutaneous elamipretide in 12 Barth syndrome patients. The initial 12-week crossover phase did not meet primary endpoints. The 168-week open-label extension (Thompson et al., Genetics in Medicine, 2024) showed sustained improvement: 6 Minute Walk Test +96.1 metres (P = .003), leg muscle strength up over 45%, cardiac function up 45%, Barth Syndrome Symptom Assessment improved 2.1 points, improved 3D left ventricular stroke, end-diastolic and end-systolic volumes, and improved cardiolipin levels versus baseline. Ten patients entered the extension; 8 reached week 168. Injection-site reactions were the most common adverse event.
Human trials in heart failure with preserved ejection fraction and in primary mitochondrial myopathy were mixed: some secondary endpoints (fatigue, muscle complaints, certain cardiac parameters) improved, but primary efficacy endpoints were not consistently met.
Preclinical. Sweetwyne et al. (Kidney International, 2017): 8 weeks of SS-31 in 24 to 26 month old mice (human equivalent 70 to 90) reversed the age-related decline in ATP production, restored redox balance, improved glomerular mitochondrial morphology, reduced p16 and SA-beta-galactosidase senescence markers, increased parietal epithelial cell density, reduced glomerulosclerosis, and preserved glomerular endothelial density. Mitchell, Pharaoh et al. (Aging Cell, 2025): 8 weeks in aged C57BL/6J mice mitigated frailty accumulation and partially reversed cardiac strain and skeletal muscle fatigue resistance deficits, with upregulation of fatty acid metabolism, mitochondrial translation and oxidative phosphorylation genes and reduced inflammation markers — without statistically significant change in epigenetic or transcriptomic age. Machiraju et al. (Scientific Reports, 2024) showed improved cardiac mitochondrial morphology and mitophagy in a Barth murine model. Siegel and colleagues (Free Radical Biology and Medicine) showed reversal of age-related redox stress and exercise intolerance, with increased muscle mass, endurance and kidney function.
Mechanistically, SS-31 concentrates in mitochondria at 5000 times cytoplasmic levels within 15 minutes, binds cardiolipin electrostatically, stabilises cristae and electron transport chain supercomplexes, and reduces ROS production by 40 to 60%. Plasma half-life is about 2 hours; clearance is 100% renal.
The translational caveat is dose: the human efficacy data is at 40 mg daily in genetic cardiolipin deficiency, while mouse doses translate to roughly 5 to 7 mg daily in humans and the practical age-related protocol is 1 to 2 mg.
User reports
From public forums
This is anecdotal and does not carry the weight of published research.
Users report steadier baseline energy and faster recovery from training, usually noticed within the first 1 to 2 weeks. The effect is described as stable, sustained energy rather than a stimulant-like rush.
The most talked-about downside is the injection site. Redness, itching, and sometimes welts are common. Most users manage this with antihistamines or hydrocortisone cream, rotate their injection sites, and find the reactions fade over time.
Some users are frustrated that the effect is not dramatic. That fits what SS-31 does — it repairs structure rather than giving an instant boost. People describe it as "things working better" rather than a distinct feeling. A few users report feeling more tired in the first few days before improvement sets in.
Users who run SS-31 first and then move to MOTS-C often report that MOTS-C and NAD+ felt more effective after the SS-31 cycle, in line with the idea that fixing the machinery first lets other compounds work.
Anecdotal reports aggregated from external platforms; not equivalent to trial data.
Users report improved baseline energy and faster training recovery, typically within 1 to 2 weeks, characterised as sustained rather than stimulant-like. Some report initial fatigue in the first few days that resolves as the repair phase progresses.
Injection-site reactions are the primary complaint and align closely with trial data: erythema, pruritus, occasional urticarial welts. In practice these are managed with antihistamines or topical hydrocortisone and site rotation, and diminish with continued use.
A recurring theme is subtlety. Because SS-31 restores electron transport chain efficiency rather than driving acute output, users describe the benefit as systems "working better" rather than a discrete sensation, and some express disappointment at the lack of a pronounced effect.
Users following the repair-then-optimise sequence (SS-31 first, then MOTS-C with NAD+) frequently report a greater response to MOTS-C and NAD+ after an SS-31 cycle — consistent with the premise that damaged mitochondria cannot use additional substrate or respond to adaptation signalling until structural integrity is restored.
User reports are individual experiences submitted by site visitors. They are not medical advice, are not verified for accuracy, and do not reflect Amino Reference's views. Read the evidence section above and talk to a clinician. Full disclaimer.
Stacking
The strongest pairing for SS-31. For people with real energy and recovery problems, run SS-31 first at 1 to 2 mg a day for 4 to 8 weeks (the repair phase), then switch to MOTS-C at 10 mg split across three injections a week (Monday, Wednesday, Friday) for weeks 5 through 12. SS-31 fixes the engine; MOTS-C then upgrades it. Newer research (Gudiksen and colleagues, 2026) shows the two lower free radicals in completely different ways, so people with only moderate age-related decline can run both together from day one. After 12 weeks, take 4 to 8 weeks off; repeat 2 to 3 times a year.
The primary stack, sequential or concurrent. Sequential: SS-31 1 to 2 mg daily for 4 to 8 weeks, then MOTS-C 10 mg split into three weekly injections (Monday, Wednesday, Friday) for weeks 5 through 12, followed by a 4 to 8 week washout, repeated 2 to 3 times per year. Gudiksen et al. (2026) showed MOTS-C reduces ROS at the nuclear transcription level via AMPK, PGC-1 alpha and NRF2 upregulation of antioxidant enzymes, whereas SS-31 acts at the membrane level via cardiolipin stabilisation — non-overlapping mechanisms, so concurrent use from day one is supported for moderate age-related decline. Preclinical data also suggests MOTS-C may support cardiolipin biosynthesis through AMPK, producing more of the molecule SS-31 protects. For significant dysfunction, sequence SS-31 first.
Runs alongside SS-31 through the whole cycle at 100 mg under the skin three times a week. SS-31 repairs the mitochondria; NAD+ gives them fuel. Taking NAD+ on its own may do little if the mitochondria are too damaged to use it, which is why some people feel nothing from NAD+ alone.
Concurrent through both phases at 100 mg subcutaneous three times per week. SS-31 restores electron transport chain structure; NAD+ supplies substrate. Conversion of NAD+ precursors to usable NAD+ is ATP-dependent, so damaged mitochondria cannot exploit precursor supplementation — the likely explanation for non-responders to NAD+ monotherapy.
Boosts the body's antioxidant defences and its ability to clear out toxins while SS-31 is repairing oxidative damage.
Enhanced antioxidant defence and detoxification during the oxidative-stress repair phase — a cytosolic antioxidant arm alongside SS-31's mitochondrial one.
Part of a longevity stack for people over 50, together with FOXO4-DRI. Epithalon works on telomeres (the protective caps on chromosomes), FOXO4-DRI clears out old worn-out cells, and SS-31 repairs mitochondria. All three can run together. After SS-31 finishes, move on to MOTS-C and NAD+.
Component of the 50+ longevity stack: Epithalon for telomere repair, FOXO4-DRI for senolytic clearance, SS-31 for mitochondrial repair — three distinct hallmarks of ageing addressed concurrently. Transition to MOTS-C and NAD+ for optimisation once the SS-31 course is complete.
The second half of the over-50 longevity stack with Epithalon. FOXO4-DRI removes senescent cells — old cells that have stopped dividing but refuse to die — while SS-31 repairs the mitochondria in the cells that remain.
Senolytic arm of the 50+ longevity stack. FOXO4-DRI eliminates senescent cells while SS-31 restores mitochondrial bioenergetics in the surviving population; Epithalon addresses telomere attrition. Run concurrently, then follow with MOTS-C and NAD+.
Supports cell regeneration and recovery while SS-31 works on mitochondrial repair. No interaction concerns. The only practical point is timing: growth hormone peptides need an empty stomach and SS-31 does not, so inject SS-31 whenever suits and keep the GH peptides on their own fasting schedule.
Growth-hormone-axis support for regeneration and recovery alongside mitochondrial repair. No interaction concerns; the only consideration is scheduling — GH secretagogues require fasting, SS-31 has no timing or fasting constraint, so each keeps its own schedule.
Helps with burning fat during energy-focused SS-31 cycles.
Adds a lipolytic arm to an energy-focused SS-31 cycle.
Promotes healing throughout the body and works against inflammatory stress. No interaction concerns; the two target completely different things and can be run at the same time.
Systemic healing and mitigation of inflammatory stress alongside the mitochondrial programme. No interaction concerns; entirely different targets, concurrent use is straightforward.
A repair peptide that can run at the same time as SS-31 with no interaction concerns. They work on completely different things.
No interaction concerns; different targets entirely. Concurrent use with SS-31 is supported.
- GLP-1 agonists
No interaction concerns. Completely different mechanisms, and no timing clashes, so they can be run at the same time.
No interaction concerns. Entirely separate mechanisms with no timing conflicts; concurrent use is supported.
Common questions
Why start with SS-31 instead of MOTS-C?
If your energy and recovery are clearly failing, start with SS-31. MOTS-C tells cells to make more energy — it is the supercharger. SS-31 repairs the structural damage — it is the mechanic. Revving a broken engine harder just makes more exhaust. If you have only moderate age-related decline and are otherwise active, newer research shows the two compounds reduce free radicals in completely different ways, so running both together is fine. If you are young and healthy, MOTS-C alone may be enough.
For significant mitochondrial dysfunction, SS-31 first remains correct: MOTS-C drives output via AMPK signalling, SS-31 restores the cardiolipin-dependent architecture that output depends on. For moderate age-related decline in otherwise functional individuals, Gudiksen et al. (2026) demonstrated that MOTS-C reduces ROS at the nuclear transcription level while SS-31 acts at the membrane level — non-overlapping mechanisms — so concurrent use is a viable option. Younger, metabolically healthy individuals may lack meaningful structural damage and can reasonably start with MOTS-C alone.
How quickly does SS-31 work?
It reaches peak levels in the blood within 15 minutes and is cleared from the blood quickly — about half of it is gone every 2 hours — but it collects inside mitochondria and stays there much longer. Repair itself takes time. Most people notice subtle energy and recovery gains within 1 to 2 weeks, and the full repair phase plays out over 4 to 8 weeks.
Peak plasma concentration within 15 minutes of subcutaneous administration; plasma half-life approximately 2 hours. Mitochondrial accumulation at 5000 times cytoplasmic levels means tissue residence far exceeds what plasma kinetics suggest. Functionally, subtle improvements in energy and recovery are typically reported within 1 to 2 weeks, with the full repair phase running 4 to 8 weeks.
Why are injection site reactions so common?
SS-31 can set off a mild histamine response — the same chemical behind allergy itching — at the injection site. It is the most common side effect in every trial. Rotate where you inject. Most reactions are mild, and antihistamines or hydrocortisone cream handle them if needed.
SS-31 triggers mild local histamine release. Injection-site reactions were the most frequently reported adverse event across all clinical trials (erythema 57%, pruritus 47%, pain 20%, urticaria 20%). Site rotation reduces frequency; most reactions are mild and self-limiting, with antihistamines or topical hydrocortisone as needed.
Can NAD+ be taken without SS-31?
You can, but if your mitochondria are damaged you may not get much from it. Turning NAD+ building blocks into usable NAD+ takes energy (ATP). If the mitochondria cannot make ATP properly, they cannot use the NAD+. That is why some people take NAD+ and feel nothing — the machinery is too broken to use the fuel.
Possible, but with damaged mitochondria the return is limited. Conversion of NAD+ precursors to usable NAD+ is ATP-dependent; if oxidative phosphorylation is compromised, precursor supplementation cannot be exploited. This is the mechanistic explanation offered for NAD+ non-responders, and the rationale for repairing with SS-31 first.
Is SS-31 cleared through the liver?
No. SS-31 leaves the body entirely through the kidneys, with no processing in the liver. If you have any kidney problems, talk to your doctor before considering it.
No. Clearance is 100% renal with no hepatic metabolism. This makes renal function the relevant screening parameter: severe kidney disease is a contraindication, and mild to moderate impairment warrants physician consultation.
Why is the dose so much lower than the doses seen online?
You may see 5 mg, 10 mg, or even 50 mg a day recommended online. Those are for diseases like Barth syndrome, where the mitochondria are fundamentally broken from birth. The trials used 40 mg a day in those patients. If you are in your 40s with falling energy and slow recovery, you have wear-and-tear damage, not a genetic disease. The practical protocol is 1 to 2 mg a day for 4 to 8 weeks, because damaged mitochondria need repair, not the doses used for broken ones.
Doses of 5 mg, 10 mg, or 50 mg per day circulating online derive from disease protocols — the Barth syndrome trials used 40 mg daily for genetic cardiolipin deficiency. Mouse studies translate to roughly 5 to 7 mg daily in humans. For age-related decline, where mitochondria are damaged rather than fundamentally defective, the practical repair protocol is 1 to 2 mg once daily for 4 to 8 weeks, subcutaneous, with no fasting or timing constraint.
Does SS-31 need to be taken fasted or at a set time?
No. The practical protocol has no fasting requirement and no specific timing. You can inject it whenever suits you. That also makes it easy to run alongside growth hormone peptides, which do need an empty stomach — just keep them on their own schedule.
No fasting or timing constraints apply to the repair protocol. This simplifies stacking with GH secretagogues, which do require a fasted state: SS-31 can be administered at any time while GH peptides keep their own fasting schedule.
Who benefits most from SS-31?
Adults over 35 to 40 with declining energy, slower recovery, and metabolic problems. By your 40s you likely carry 10 to 20 years of built-up mitochondrial damage, and damaged mitochondria cannot respond well to other compounds until they are repaired. Younger, healthy people may not need it at all. Training, food, and sleep still come first — SS-31 adds to a good foundation, it does not replace one.
Adults over 35 to 40 presenting with energy decline, slow recovery, and metabolic issues — a population likely carrying 10 to 20 years of accumulated cardiolipin and electron transport chain damage that blunts response to optimisation signals. For younger or metabolically healthy individuals SS-31 may be unnecessary. Training, nutrition and sleep remain primary; the compound enhances rather than substitutes for that foundation.
References
- Szeto HH. First-in-class cardiolipin-protective compound as a therapeutic agent to restore mitochondrial bioenergetics. British Journal of Pharmacology. 2014;171:2029-2050.
- Thompson WR, et al. A phase 2/3 randomized clinical trial followed by an open-label extension to evaluate the effectiveness of elamipretide in Barth syndrome. Genetics in Medicine. 2021;23:471-478.
- Thompson WR, et al. Long-term efficacy and safety of elamipretide in patients with Barth syndrome: 168-week open-label extension results of TAZPOWER. Genetics in Medicine. 2024;26(7):101133.
- Sweetwyne MT, et al. The mitochondrial-targeted peptide, SS-31, improves glomerular architecture in mice of advanced age. Kidney International. 2017;91:1126-1145.
- Mitchell W, Pharaoh G, Tyshkovskiy A, et al. The mitochondria-targeted peptide therapeutic elamipretide improves cardiac and skeletal muscle function during aging without detectable changes in tissue epigenetic or transcriptomic age. Aging Cell. 2025;24(6):e70026.
- Chavez JD, et al. Mitochondrial protein interaction landscape of SS-31. Proceedings of the National Academy of Sciences. 2020;117(26):15363-15373.
- Birk AV, et al. The mitochondria-targeted compound SS-31 re-energizes ischemic mitochondria by interacting with cardiolipin. Journal of the American Society of Nephrology. 2013;24:1250-1261.
- Machiraju P, et al. SS-31 treatment ameliorates cardiac mitochondrial morphology and defective mitophagy in a murine model of Barth syndrome. Scientific Reports. 2024;14:13551.
- Siegel MP, et al. Improving mitochondrial function with SS-31 reverses age-related redox stress and improves exercise tolerance in aged mice. Free Radical Biology and Medicine. 2013;65:1234-1242.
- Campbell MD, et al. Long-term treatment with elamipretide enhances healthy aging phenotypes in mice. Aging Pathobiology and Therapeutics. 2022;4(3):76-83.
- Sabbah HN, et al. Elamipretide: a review of its structure, mechanism of action, and therapeutic potential. International Journal of Molecular Sciences. 2025;26(3):944.
- Gudiksen A, Hansen CC, Van der Stede T, et al. MOTS-c improves intrinsic muscle mitochondrial bioenergetic health and efficiency in a PGC-1 alpha/AMPK-dependent manner. Free Radical Biology and Medicine. 2026;246:682-696.
This entry has been reviewed and expanded with additional reference material. Units are recomputed from the stated protocol.