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A small peptide aimed at the cell's power plants; FDA gave it early, conditional approval for Barth syndrome, a rare genetic disease.
A four-amino-acid peptide that binds cardiolipin in the inner mitochondrial membrane; granted FDA accelerated approval as Forzinity in September 2025 to improve muscle strength in Barth syndrome, while trials in primary mitochondrial myopathy and dry macular degeneration have missed or not yet reported their primary endpoints.
Forzinity vials are labeled for refrigeration at 2–8 °C (36–46 °F) and labeled not to be frozen.
Side effects and warnings
Skin reactions where the shot is given are common. In one trial, all 12 treated patients had redness. Pain, hard lumps, itching, bruising and hives were also common.
Allergic reactions can happen, including serious ones that need emergency care. Rash, skin bumps, eczema-like skin and cough have been reported.
A rise in a type of white blood cell (eosinophils) can happen after 30 days or more. It usually peaks around 90 days and then goes back to normal.
A summary of the sources on this page, not medical advice.
Sequence: D-Arg-Dmt-Lys-Phe-NH2 (Dmt is 2,6-dimethyl-L-tyrosine; C-terminal amide)
Origin
Discovered by: Hazel H. Szeto (Weill Cornell Medical College) and Peter W. Schiller (Clinical Research Institute of Montreal)
Year: 2004
Developer: Stealth BioTherapeutics (renamed Mighty Therapeutics in June 2026)
What it is
SS-31 is also called elamipretide. It is a short chain of amino acids (a peptide). It is made in a lab and is only four amino acids long. It was designed to get inside mitochondria. These are tiny parts of cells that make energy. Once inside, it sticks to a fat called cardiolipin. Cardiolipin sits in the inner wall of the mitochondria. It helps hold the energy-making parts together. In a rare inherited disease called Barth syndrome, cardiolipin does not work properly.
In September 2025 the FDA approved elamipretide. The brand name is Forzinity. It is a shot given once a day. It is meant to improve muscle strength in people with Barth syndrome. They must weigh at least 30 kg. This is an “accelerated” approval. That means it is based on an early sign that it works. Another trial must still confirm it. This is the only approved use.
Elamipretide is the tetrapeptide D-Arg-Dmt-Lys-Phe-NH2 (Dmt, 2,6-dimethyltyrosine; C32H49N9O5, 639.8 g/mol), one of the Szeto-Schiller peptides. Its alternating aromatic and cationic residues give a net +3 charge at physiological pH; the SS peptides are cell-permeable and were reported to concentrate about 1000-fold in the inner mitochondrial membrane (Zhao et al., J Biol Chem 2004). It binds cardiolipin through electrostatic and hydrophobic interactions; the label describes it as a mitochondrial cardiolipin binder that improves mitochondrial morphology and function. Preclinical work proposes that binding prevents cardiolipin from converting cytochrome c into a peroxidase.
Label pharmacokinetics: after subcutaneous injection, peak concentrations occur at 0.5–1 hour and absolute bioavailability is about 92%. Volume of distribution is about 0.5 L/kg and plasma protein binding about 39%. Elamipretide is degraded from the C-terminus to inactive tri- and dipeptide metabolites, and about 100% of a dose is recovered in urine within 48 hours. Exposure rises with renal impairment, and the label halves the dose when eGFR is under 30 mL/min without dialysis.
Who made it and when
Two scientists worked together for many years to create this peptide. Hazel Szeto worked at Weill Cornell Medical College in New York. Peter Schiller was a peptide chemist in Montreal. “SS” stands for Szeto-Schiller. They made a family of small peptides. Some of them turned out to collect inside mitochondria. The key paper about this came out in 2004.
A Massachusetts company called Stealth BioTherapeutics then tested it in people. Over time it used the names MTP-131, Bendavia and elamipretide. It was first tested in heart and kidney conditions. Later the company switched to rare mitochondrial diseases. It also focused on a type of vision loss that comes with age.
The Szeto-Schiller peptides were developed jointly at Weill Cornell and the Clinical Research Institute of Montreal. Zhao et al. (J Biol Chem 2004) reported that these cell-permeable peptides, built on alternating aromatic and basic residues with dimethyltyrosine, localise to the inner mitochondrial membrane, reduce mitochondrial ROS, inhibit permeability transition and swelling, and improved contractile force in an ex-vivo reperfused heart. Szeto’s 2014 review in the British Journal of Pharmacology describes SS-31 as the first cardiolipin-protective compound. The early US patent covering the peptides’ use to prevent mitochondrial permeability transition (US 7,576,061; Cornell Research Foundation and IRCM; priority 2003) is one of six US patents listed on the Forzinity label; Google Patents gives its expiry as 2026-01-20.
Stealth BioTherapeutics ran studies in reperfusion injury during coronary intervention (EMBRACE STEMI) and renal-artery angioplasty (EVOLVE), heart failure and skeletal muscle function in older adults before concentrating on primary mitochondrial myopathy, Barth syndrome and dry age-related macular degeneration. The Barth syndrome NDA (215244) was submitted on 2024-01-29, received a complete response on 2025-05-15, and was approved under the accelerated pathway on 2025-09-19, with a rare pediatric disease priority review voucher.
What the data say
The approval is based on very few people. Barth syndrome is extremely rare. The key trial had only 12 patients. In the first part, patients swapped between the drug and a dummy shot (placebo). They took each one for 12 weeks. In this part, patients did not know which one they were getting. Here the drug did not beat the placebo. It did no better on walking distance or tiredness, the two main goals. Leg muscle strength went up later. That happened over several years when everyone knew they were getting the drug. The FDA accepted this later gain as an early sign that it works.
Results for other uses have been mixed. A large trial in adults with an inherited mitochondrial muscle disease did not work. A trial in an eye disease called dry macular degeneration missed its main goals. A larger eye trial is still running.
TAZPOWER (NCT03098797): 12 males with Barth syndrome received 40 mg subcutaneously daily in a 12-week crossover. Neither primary endpoint (6MWT, BTHS-SA total fatigue) was met. In the open-label extension, 6MWT improved by 95.9 m at 36 weeks (p = 0.024), and the label reports median knee extensor strength gains of 34 to 68 newtons from weeks 12 to 168 against a baseline of 124 N, as descriptive statistics without a control group.
MMPOWER-3 (NCT03323749; n=218): at 24 weeks the least-squares 6MWT difference was −3.2 m (p = 0.69) and PMMSA fatigue did not differ. NuPOWER (NCT05162768; n=102, 60 mg daily, nuclear-DNA disease) has no posted results.
ReCLAIM-2 (NCT03891875; n=176): no significant effect on low-luminance visual acuity or geographic atrophy growth at 48 weeks; ellipsoid-zone loss progressed about 43% more slowly (nominal p = 0.0034). ReNEW (NCT06373731; n=313) has as its registered primary endpoint the week-48 rate of change in the macular area of photoreceptor loss, the ellipsoid-zone measure that Ehlers et al. said would serve as the Phase 3 primary endpoint.
Safety: injection-site reactions occurred in all treated Barth patients; hypersensitivity and eosinophilia are labeled.
Regulatory picture
Elamipretide is FDA approved for only one narrow use. It is for muscle strength in children and adults with Barth syndrome. They must weigh at least 30 kg. The approval comes with conditions. The FDA first said no in May 2025. It then gave accelerated approval in September 2025. This was based on the muscle strength results. The FDA required the company to run a new trial against a placebo. If that trial does not show a real effect, the FDA can take the approval away. This new trial started signing up patients in 2026.
It is not approved for mitochondrial muscle disease, macular degeneration or anything else. An approved product already exists. So pharmacies may not make copies of it regularly or in large amounts. The exception is if it is on the FDA’s drug shortage list.
Approval: Forzinity (elamipretide) injection, NDA 215244, accelerated approval under section 506(c) and 21 CFR 314.510 on 2025-09-19 for adult and pediatric Barth syndrome patients weighing at least 30 kg, based on knee extensor strength as an intermediate clinical endpoint. The postmarketing requirement is a randomized, double-blind, placebo-controlled trial, with study completion scheduled for 09/2029; 4TAZPower (NCT07531251, Phase 3b/4, ages 5–55) began in July 2026. The labeled dosage is 40 mg subcutaneously once daily, or 20 mg with eGFR under 30 mL/min not on dialysis.
Compounding: elamipretide is not on the 503A bulks list or in any 503A nomination category. Because it is the active ingredient of an approved drug, section 503A bars compounding drugs that are essentially copies of it regularly or in inordinate amounts while it is commercially available (a product on FDA’s drug shortage list does not count as commercially available), so this article records it as restricted.
Other programmes: none of the other indications has been filed or approved. No approval outside the US was verified for this article.
Dose
Doses reported in trials and studies
How dosing worked in the studies
In the TAZPOWER trial, 12 males with Barth syndrome got 40 mg under the skin once a day. They also got a dummy treatment (placebo). The order was decided by chance (a 12-week crossover). After that, everyone could take the drug and knew it (an open-label extension). In other trials, adults were assigned by chance to these shots or a placebo. MMPOWER-3 used 40 mg in 218 people with primary mitochondrial muscle disease for 24 weeks. It was later stopped early. ReCLAIM-2 used 40 mg in 176 people with dry macular degeneration for 48 weeks. NuPOWER used 60 mg in 102 people with mitochondrial disease for 48 weeks. An earlier trial, MMPOWER, assigned 36 adults by chance to placebo or to a drip into a vein. The doses were 0.01, 0.10 or 0.25 mg/kg/h over 2 hours on 5 days in a row. Each group got a higher dose than the one before. ReNEW is testing 40 mg once a day against placebo for 96 weeks.
Label dosing (FDA-approved products)
The Forzinity label gives 40 mg subcutaneously once daily, at the same time each day, for Barth syndrome patients weighing at least 30 kg. A missed dose is skipped, not doubled. Adults with eGFR under 30 mL/minute who are not on dialysis get 20 mg subcutaneously once daily. The label says there is not enough information to recommend a dose for adults with eGFR under 30 mL/minute who are on dialysis, or for children weighing 30 kg or more who have renal impairment. It also says safety and effectiveness have not been established in children weighing less than 30 kg. (Forzinity (elamipretide) injection prescribing information (FDA label, 9/2025))
Doses reported in studies, exactly as the cited trial reported them. They are not personal dosing instructions. Population, route and schedule matter more than the number.
TAZPOWER: 12 males aged 12 and over with genetically confirmed Barth syndrome. Dose: 40 mg subcutaneous once daily; 12-week crossover versus placebo with a 4-week washout, then open-label extension. Result: Neither primary endpoint (6-minute walk, BTHS-SA fatigue) was met in the crossover; at 36 weeks of the open-label extension, 6-minute walk improved by 95.9 m (p = 0.024) (Reid Thompson et al., Genet Med 2021)
MMPOWER-3: 218 adults aged 16–80 with genetically confirmed primary mitochondrial myopathy. Dose: 40 mg subcutaneous once daily for 24 weeks versus placebo. Result: 6-minute walk difference −3.2 m (95% CI −18.7 to 12.3; p = 0.69); no difference in PMMSA total fatigue (Karaa et al., Neurology 2023)
NuPOWER: 102 adults aged 18–70 with primary mitochondrial disease due to nuclear DNA variants. Dose: 60 mg subcutaneous once daily for 48 weeks versus placebo. Result: No peer-reviewed report found; Stealth presented overall outcomes and a POLG1-subgroup analysis at Euromit in 2026
ReCLAIM-2: 176 adults aged 55 and over with dry age-related macular degeneration and non-central geographic atrophy. Dose: 40 mg subcutaneous once daily for 48 weeks versus placebo (randomised 2 to 1). Result: Missed both primary endpoints (low-luminance visual acuity, geographic atrophy growth); slower ellipsoid-zone loss on predefined secondary measures, nominal p values only (Ehlers et al., Ophthalmol Sci 2025)
ReNEW: 313 adults aged 55 and over with dry age-related macular degeneration. Dose: 40 mg subcutaneous once daily for 96 weeks versus placebo.
4TAZPower (confirmatory): 48 males aged 5–55 with genetically confirmed Barth syndrome, planned. Dose: Subcutaneous elamipretide (80 mg/mL solution) once daily versus matching placebo; the registry does not state the milligram dose.
12 males aged 12 and over with genetically confirmed Barth syndrome
40 mg subcutaneous once daily; 12-week crossover versus placebo with a 4-week washout, then open-label extension
Neither primary endpoint (6-minute walk, BTHS-SA fatigue) was met in the crossover; at 36 weeks of the open-label extension, 6-minute walk improved by 95.9 m (p = 0.024) (Reid Thompson et al., Genet Med 2021)
176 adults aged 55 and over with dry age-related macular degeneration and non-central geographic atrophy
40 mg subcutaneous once daily for 48 weeks versus placebo (randomised 2 to 1)
Missed both primary endpoints (low-luminance visual acuity, geographic atrophy growth); slower ellipsoid-zone loss on predefined secondary measures, nominal p values only (Ehlers et al., Ophthalmol Sci 2025)
48 males aged 5–55 with genetically confirmed Barth syndrome, planned
Subcutaneous elamipretide (80 mg/mL solution) once daily versus matching placebo; the registry does not state the milligram dose
—
Doses in other published studies
Published studies not listed in the trials table above: smaller or unregistered human studies first, then animal and cell studies. Doses are shown exactly as each study reported them. Animal studies report weight-based doses, absolute amounts or concentrations; none translates directly to people, and none is converted here.
Subjects
Design
Dose
Finding
Source
Humans: 36 adults with genetically confirmed primary mitochondrial myopathy
Intravenous elamipretide at 0.01, 0.10 or 0.25 mg/kg/h (three sequential escalating-dose cohorts), or placebo, infused over 2 hours on 5 consecutive days; primary measure (6-minute walk) taken after the 5 days of treatment
The highest-dose group walked a mean 64.5 m farther at day 5, compared with 20.4 m farther in the placebo group (p = 0.053), with a dose-dependent trend (p = 0.014); no significant differences were seen in other efficacy or safety endpoints.
4 mg or 40 mg elamipretide subcutaneously once daily for 28 consecutive days, versus placebo
The change in left ventricular end-systolic volume at week 4 was not significantly different from placebo with either dose, and rates of study drug-related adverse events were similar across the three groups.
Single intravenous infusion of 0.25 mg/kg body weight per hour for 2 hours, versus vehicle placebo; outcomes reassessed 7 days after the infusion
Immediately after the infusion, the change in maximal mitochondrial ATP production in the first dorsal interosseous (hand) muscle favoured elamipretide over placebo (absolute change P = 0.055; percent change P = 0.045), with no difference at day 7, no significant change in resting mitochondrial coupling and no significant effect on fatigue resistance.
Humans: adults with first-time anterior ST-elevation myocardial infarction due to proximal or mid left anterior descending artery occlusion, undergoing primary percutaneous coronary intervention
Phase 2a multicentre, randomized, double-blind trial versus placebo (EMBRACE STEMI; drug given as MTP-131)
Intravenous infusion at 0.05 mg/kg/h for 1 hour, versus placebo, in patients undergoing primary PCI
Infarct size by 72-hour CK-MB area under the curve was not significantly reduced, and the drug was not associated with improvement in prespecified MRI, angiographic, ECG or clinical outcomes; administration was reported as safe and well tolerated.
40 mg/day subcutaneous elamipretide for 4 weeks and placebo for 4 weeks in randomized order, separated by a 4-week washout
The 6-minute walk difference of 19.8 m versus placebo was not statistically significant (95% CI -2.8 to 42.5; P = 0.0833), patient-reported fatigue scores showed nominally significant improvements, and injection-site reactions were the most commonly reported adverse events with elamipretide (80%), mostly mild.
Mice: young (5 months) and aged (26 months) female C57BL/6Nia
Controlled animal study versus saline-filled pumps
SS-31 3 mg/kg/day delivered by subcutaneously implanted osmotic minipump for 8 weeks (pumps replaced after 4 weeks)
In aged mice, treatment reversed age-related declines in maximal mitochondrial ATP production and coupling, and treated aged mice had greater gastrocnemius fatigue resistance and mass and longer treadmill endurance.
Examples for the freeze-dried powder, as reported by protocol websites, not taken from studies. The water amount only sets the concentration (how much is in each mL); it does not change how much of the compound is in the vial. Each concentration assumes the vial really holds its labelled amount and the final liquid volume equals the water added.
Vial
Water added
Concentration
10 mg
1.0 mL
10 mg/mL
10 mg
2.0 mL
5 mg/mL
50 mg
2.5 mL
20 mg/mL
Clean the rubber tops of both vials with an alcohol swab.
Add the water slowly, letting it run down the inside wall of the vial rather than onto the powder.
Swirl or roll gently until the powder dissolves; protocol sites advise against shaking.
The liquid should be clear. If it is cloudy or has specks in it, do not use it. Clear liquid does not show that the product is pure, the right strength or sterile.
Write the date and the concentration on the vial, and keep it in the fridge (2–8 °C). No safe storage time after mixing has been established for these products.
Products sold as "research peptides" have not gone through FDA review for safety, effectiveness or quality. Bacteriostatic water does not sterilize a contaminated powder. It contains benzyl alcohol, and its label says it is not for use in newborns. To work out a volume from your own numbers, use the converter.
Doses described in clinical or compounding practice
From FDA labels and documents, other regulators, published reviews and professional references, as each source states them. Unless a source says otherwise, these describe practice or proposals, not results tested in trials. Reading doses safely: how concentration and syringe markings work.
The Forzinity label gives 40 mg subcutaneously once daily, at the same time each day, for Barth syndrome patients weighing at least 30 kg. A missed dose is skipped, not doubled. Adults with eGFR under 30 mL/minute who are not on dialysis get 20 mg subcutaneously once daily. The label says there is not enough information to recommend a dose for adults with eGFR under 30 mL/minute who are on dialysis, or for children weighing 30 kg or more who have renal impairment. It also says safety and effectiveness have not been established in children weighing less than 30 kg. (Forzinity (elamipretide) injection prescribing information (FDA label, 9/2025), FDA label)
This case series from Stealth's expanded access program (three children under 12 with Barth, MEGDEL or Sengers syndrome) reports that about 0.5 mg/kg/day was well tolerated. Its dosing table sends children under 1 year to intravenous elamipretide, with the subcutaneous product 'not to be used' in them. From age 1 the table gives 5 mg SQ daily under 10 kg, 10 mg for 10–20 kg, 20 mg for 20–40 kg and 40 mg over 40 kg. The authors say the under-10, 20–40 and over-40 kg bands are 'theoretical and based on extrapolation' and that no safety data exist for some of the categories. (Koenig MK et al. Use of elamipretide in patients assigned treatment in the compassionate use program: case series in pediatric patients with rare orphan diseases. JIMD Reports 2023;64(1):65-70, Peer-reviewed)
Unverified, and not a recommendation. These are amounts people describe in online forums such as Reddit, collected so researchers can see how practice differs from the evidence. These forum accounts are not clinical evidence, even where they overlap studied doses. Products sold online as "research peptides" are not FDA approved, and their identity, purity and strength are not verified; they can be mislabeled, contaminated or wrongly dosed.
What people report
In the threads reviewed (r/Peptides, r/Biohackers and r/longevity, 2025 to 2026), people describing subcutaneous use gave amounts from about 0.25 mg to 10 mg daily, many between 1 and 5 mg daily, with some describing larger amounts every other day or twice weekly. The main disagreement was whether high amounts like the 40 mg daily trial dose are needed by people without disease. Reported side effects included early fatigue, exhaustion or brain fog; injection-site itching; worse urinary urgency; dizziness on standing; and bloodshot eyes. Commenters also questioned product sterility and contents.
How this compares with the studies
Published studies used 40 mg or 60 mg subcutaneously once daily in mitochondrial and eye disease, 4 mg or 40 mg once daily for 28 days in heart failure, and short weight-based intravenous infusions (0.01 to 0.25 mg/kg/h). Thread amounts come from unregulated products of unverified content, used largely by people without those diagnoses, so exposure, safety and efficacy cannot be compared. Some threads cite the 40 mg daily trial dose.
Open questions a study would need to answer
Do the lower daily subcutaneous amounts described in these threads change any measured outcome in people without mitochondrial disease, given that the 4 mg arm of PROGRESS-HF did not significantly change its primary endpoint?
Are the early fatigue and brain-fog reports linked to elamipretide itself, to contaminants or mislabeled content in unregulated products, or to expectation effects?
Do the eosinophilia and hypersensitivity reactions listed on the Forzinity label also occur with the lower or intermittent amounts described in these threads?
2025-05-15 · Complete response letter: FDA declined to approve the original new drug application; Stealth's resubmission of 2025-08-15 was accepted as a complete response; the approved label bases accelerated approval on knee extensor muscle strength, an intermediate clinical endpoint (per FDA's approval letter and label). (source)
2025-09-19 · Accelerated approval: FDA granted accelerated approval (NDA 215244). The letter requires a randomized, double-blind, placebo-controlled confirmatory trial, with study completion scheduled for 09/2029, and states the approval may be withdrawn if that trial does not verify a clinical effect. (source)
2026-08-24 · Warning letter (research-use seller): FDA's warning letter to Peak Performance Peptides named SS-31 among products sold with "research use only" labelling that FDA considers unapproved new drugs intended for human use. (source)
Side effects and warnings
Skin reactions where the shot is given are common. In one trial, all 12 treated patients had redness. Pain, hard lumps, itching, bruising and hives were also common.
Allergic reactions can happen, including serious ones that need emergency care. Rash, skin bumps, eczema-like skin and cough have been reported.
A rise in a type of white blood cell (eosinophils) can happen after 30 days or more. It usually peaks around 90 days and then goes back to normal.
It contains benzyl alcohol. The label warns this can cause a breathing problem (gasping syndrome) in newborns. It is not approved for newborns.
It should not be used by people who have had a serious allergic reaction to elamipretide or any other ingredient in Forzinity.
Lab tests show it blocks a protein that moves drugs, called MATE1. Label studies found it did not change how aspirin, clopidogrel or heparin work or how the body handles them.
Full lists are in the .
Reported side effects
Injection-site reactions (label); in the crossover trial all 12 treated patients had erythema, with pain, induration, pruritus, bruising and urticaria also common
Hypersensitivity reactions, including serious allergic reactions requiring emergency treatment; rash, papular lesions, eczematous dermatitis and cough reported
Eosinophilia with treatment of 30 days or longer, generally peaking around 90 days and returning to baseline; not linked to clinical findings in the label
Contains benzyl alcohol; the label warns of gasping syndrome in neonates and the product is not approved for neonates
Interactions
In vitro, elamipretide inhibits the MATE1 transporter; it did not inhibit or induce the main CYP enzymes tested (label)
Label studies found no effect on the pharmacokinetics or activity of aspirin, clopidogrel or unfractionated heparin
Contraindications
Serious hypersensitivity to elamipretide or any excipient in Forzinity
Storage
Unopened: Forzinity vials are labeled for refrigeration at 2–8 °C (36–46 °F) and labeled not to be frozen.
Reconstituted / in use: Not applicable; Forzinity is a ready-to-use solution. The label states that an opened vial may be kept refrigerated or at 20–25 °C and is discarded 8 days after first opening.
Product characteristics
Form: Ready-to-use aqueous solution for subcutaneous injection, 280 mg/3.5 mL (80 mg/mL) single-patient-use vials, preserved with benzyl alcohol
Appearance: Clear, colorless to yellow solution
Solubility: The hydrochloride salt is freely soluble in water (label)
Stability: FDA's approval letter sets expiry dating at 48 months from manufacture when stored at 2–8 °C
Compound information
Synthetic tetrapeptide containing one D-amino acid (D-arginine) and the non-natural residue 2,6-dimethyltyrosine, formulated as the trihydrochloride salt in the approved product.
Molecule, patents, enforcement history, full trial tables and compound details are in the .
Patents
US 7,576,061 · Cornell Research Foundation and Institut de Recherches Cliniques de Montréal · Methods for preventing mitochondrial permeability transition (Szeto, Zhao, Schiller; priority 2003; listed on the Forzinity label; Google Patents gives expiry as 2026-01-20)
Common questions
What is SS-31 (elamipretide)?
SS-31 is also called elamipretide. It is a short chain of amino acids (a peptide). It is made in a lab and is only four amino acids long. It was designed to get inside mitochondria. These are tiny parts of cells that make energy. Once inside, it sticks to a fat called cardiolipin. Cardiolipin sits in the inner wall of the mitochondria. It helps hold the energy-making parts together. In a rare inherited disease called Barth syndrome, cardiolipin does not work properly.
Is SS-31 (elamipretide) FDA approved?
FDA approved as Forzinity, for muscle strength in Barth syndrome, a rare genetic condition (accelerated approval).
What have studies found?
In the main Barth syndrome trial (12 patients), the drug did not beat a dummy treatment (placebo) on walking or tiredness. Walking distance improved by 95.9 m after 36 weeks, when everyone knew they were on the drug.
Larger trials in mitochondrial muscle disease (218 adults), heart failure (71 adults) and dry macular degeneration (176 adults) did not meet their main goals.
How was it dosed in studies?
In the TAZPOWER trial, 12 males with Barth syndrome got 40 mg under the skin once a day. They also got a dummy treatment (placebo). The order was decided by chance (a 12-week crossover). After that, everyone could take the drug and knew it (an open-label extension). In other trials, adults were assigned by chance to these shots or a placebo. MMPOWER-3 used 40 mg in 218 people with primary mitochondrial muscle disease for 24 weeks. It was later stopped early. ReCLAIM-2 used 40 mg in 176 people with dry macular degeneration for 48 weeks. NuPOWER used 60 mg in 102 people with mitochondrial disease for 48 weeks. An earlier trial, MMPOWER, assigned 36 adults by chance to placebo or to a drip into a vein. The doses were 0.01, 0.10 or 0.25 mg/kg/h over 2 hours on 5 days in a row. Each group got a higher dose than the one before. ReNEW is testing 40 mg once a day against placebo for 96 weeks.
What are the side effects and warnings?
Skin reactions where the shot is given are common. In one trial, all 12 treated patients had redness. Pain, hard lumps, itching, bruising and hives were also common.
Allergic reactions can happen, including serious ones that need emergency care. Rash, skin bumps, eczema-like skin and cough have been reported.
A rise in a type of white blood cell (eosinophils) can happen after 30 days or more. It usually peaks around 90 days and then goes back to normal.
It contains benzyl alcohol. The label warns this can cause a breathing problem (gasping syndrome) in newborns. It is not approved for newborns.
It should not be used by people who have had a serious allergic reaction to elamipretide or any other ingredient in Forzinity.
Lab tests show it blocks a protein that moves drugs, called MATE1. Label studies found it did not change how aspirin, clopidogrel or heparin work or how the body handles them.
References
This page summarises the published sources below. PeptideBasics101 does no original research. Trial doses and results are reported as the cited study or label reported them. Sources can themselves be wrong or superseded; if you find a statement here that does not match its source, please tell us through our corrections process. Sources were last checked on 2026-11-01.
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