Mitochondrial Disease: Medication and Treatment Options

No cure exists for mitochondrial disease, a group of disorders caused by mutations that cripple the cell’s energy-producing machinery. Treatment today is a patchwork: a handful of drugs approved for narrow subtypes, widely used supplements with limited hard evidence, symptom-by-symptom management, and a growing roster of experimental therapies in early trials. The landscape is changing faster than it has in decades, but for most patients the daily reality still involves combining several partial measures rather than relying on any single treatment.

Approved Drugs Target Specific Subtypes, Not Mitochondrial Disease as a Whole

One of the first things that surprises people about mitochondrial disease treatment is that the few approved drugs each address just one condition within the broader family. There is no pill for “mitochondrial disease” the way there is a statin for high cholesterol. The genetic and clinical diversity is simply too vast. Several late-stage clinical trials have failed or produced inconclusive results, and regulatory approvals remain rare.

Omaveloxolone, sold as Skyclarys, was approved by the FDA in February 2023 for Friedreich’s ataxia in people aged 16 and older, making it the first and only FDA-approved treatment for that condition. The European Commission followed with approval in February 2024.¹ Omaveloxolone works by activating a protective pathway called Nrf2, which is underactive in Friedreich’s ataxia cells. In the pivotal trial, patients taking 150 mg daily for 48 weeks showed a modest but statistically meaningful improvement in neurological function compared to placebo, with most side effects limited to upper respiratory infections and headache.¹ Modest is the operative word: the drug slows progression rather than reversing it, and it does not address the underlying genetic defect.

Elamipretide is a peptide that binds to cardiolipin, a fat molecule in the inner mitochondrial membrane that helps keep the energy-producing chain organized. It received accelerated FDA approval for Barth syndrome, a rare mitochondrial condition that mainly affects boys and young men with severe heart and muscle problems.² The path to approval was bumpy: in a crossover trial, elamipretide did not produce significant improvement in the primary endpoints of walking distance or fatigue. But during a long open-label extension lasting over three years, sustained benefits emerged in exercise capacity, muscle strength, and some cardiac measures.³ That pattern, where short controlled trials miss the benefit but longer follow-up catches it, is a recurring headache in mitochondrial disease research.

Idebenone, a synthetic relative of coenzyme Q10, is approved in Europe for Leber hereditary optic neuropathy (LHON), a mitochondrial condition that causes rapid, severe vision loss in young adults. At a dose of 900 mg daily, evidence from a randomized trial combined with real-world follow-up data showed that idebenone helps prevent further vision loss and promotes some recovery compared to the disease’s natural course.⁴ A Welsh cohort study found that by 24 months of treatment, a significantly higher proportion of treated patients showed clinically relevant recovery of vision compared to untreated patients.⁵ Idebenone is not approved in the United States for LHON, though some physicians prescribe it off-label or through compassionate-use programs.

The Supplement Cocktail Most Patients Are Prescribed

Walk into a mitochondrial disease clinic and you will almost certainly walk out with a list of dietary supplements. Surveys of mitochondrial medicine physicians show that virtually all of them recommend supplements, and most patients end up taking four or more, with coenzyme Q10, L-carnitine, and riboflavin (vitamin B2) being the most common.⁶ The majority of patients in those surveys reported feeling some health benefit, though subjective perception and placebo effects are hard to untangle in the absence of large controlled trials.

Coenzyme Q10 (CoQ10) has the strongest rationale in patients who have a primary deficiency in the CoQ10 biosynthetic pathway, where supplementation is genuinely fundamental to treatment. In patients whose mitochondrial disease does not stem from a CoQ10 deficiency, the thinking is that supplemental CoQ10 can still help by restoring electron flow in the energy-production chain and acting as an antioxidant.⁷ One study found that patients receiving CoQ10 (ubidecarenone) showed a statistically significant reduction in a marker of cellular damage, though the effect on direct DNA damage was more modest.⁸ Riboflavin is included because it is a precursor to FAD, a molecule needed by several enzymes in the mitochondrial chain; L-carnitine helps shuttle fatty acids into mitochondria for energy production. The evidence base for each is thin by the standards of modern medicine, but the low cost and minimal side-effect profile keep them in widespread clinical use.

Symptom-Specific Treatments

Because mitochondrial disease can hit almost any organ system, much of day-to-day management focuses on treating the specific symptoms each patient develops. The heart, brain, muscles, eyes, and gut are all frequent targets, and each organ’s problems require their own specialists and therapies.

Stroke-Like Episodes in MELAS

MELAS syndrome, one of the better-known mitochondrial conditions, features recurrent stroke-like episodes along with lactic acidosis and muscle problems. Evidence points to a deficiency of nitric oxide (NO) in the blood vessels as a contributor to these episodes, because NO is needed to keep small blood vessels dilated. L-arginine, an amino acid that the body converts into NO, has become a common intervention. A systematic review found that intravenous arginine appears effective at improving symptoms during acute stroke-like attacks, while daily oral arginine supplementation improves blood vessel function and may help prevent future episodes.⁹

L-citrulline, another amino acid, raises NO levels even more effectively than L-arginine, and may therefore be a better option.¹⁰ However, citrulline’s clinical track record in MELAS patients is much thinner. A phase I dose-finding study has investigated the maximum tolerated dose of L-citrulline in adults with MELAS, but the clinical studies that would prove it works better than arginine have not yet been completed.¹¹

Heart Problems

Mitochondrial cardiomyopathy, where the heart muscle itself is energy-starved, is one of the more dangerous complications. Many patients develop a hypertrophic pattern that eventually progresses to a dilated, weakened heart. Standard heart failure medications like ACE inhibitors and beta-blockers are generally well tolerated and are typically started once systolic dysfunction appears, though robust evidence specifically demonstrating their benefit in mitochondrial patients is lacking.¹² What is distinctive about mitochondrial heart disease is the rhythm problem. Conduction defects on an EKG carry a particularly high risk of dangerous arrhythmias. In the largest reported patient cohort, a complete bundle branch block or fascicular block carried roughly a three-fold higher risk of heart failure and nearly a seven-fold higher risk of arrhythmias. Because of this, the Mitochondrial Medicine Society and cardiac specialists recommend a low threshold for pacemaker implantation to prevent sudden death.¹²

Medications to Avoid

Equally important as knowing what to take is knowing what to stay away from. Some commonly prescribed drugs are toxic to mitochondria and can worsen the disease or trigger life-threatening crises. Patients with mitochondrial disease who need any of these medications should be carefully monitored with bloodwork including creatine kinase and lactate levels.¹³

The most notorious offender is valproic acid (valproate), a seizure medication widely used in neurology. Valproate is known to have particularly dangerous effects in patients carrying POLG1 mutations: it can trigger fatal liver failure. It has also been associated with severe worsening in patients with myoclonic epilepsy with ragged red fibers, another mitochondrial condition. Current guidance holds that valproate should only be used in mitochondrial patients as a last resort during drug-resistant status epilepticus when no alternative is available.¹⁴ Other drugs with known mitochondrial toxicity include certain antibiotics (aminoglycosides are of particular concern in patients with specific mitochondrial DNA mutations), some anesthetics, and statins in high doses. A good rule of thumb: any new medication should be discussed with the patient’s metabolic or mitochondrial specialist before starting.

The Ketogenic Diet for Seizures and Beyond

The ketogenic diet, a high-fat, very-low-carbohydrate eating plan that forces the body to burn fat instead of glucose, has been studied as a therapy for mitochondrial disease, especially for seizure control. A prospective controlled study in patients with mitochondrial epilepsy found that about 41% of those on the diet achieved at least a 50% seizure reduction at three months. The results were even more striking in patients with MELAS or mitochondrial DNA mutations, where response rates exceeded 90%.¹⁵

There are real risks, though. A systematic review identified cases of rhabdomyolysis (dangerous muscle breakdown) in adults with mitochondrial DNA deletion-related myopathy who tried the diet, forcing them to stop. Three patients with POLG mutations died while on the diet, although their survival was not different from POLG patients who were not on it, suggesting the deaths may have been from disease progression rather than the diet itself.¹⁶ The bottom line is that the ketogenic diet can be powerful for seizure control in certain mitochondrial subtypes, but it is not universally safe and requires close medical supervision, particularly in patients with POLG mutations or large-scale mitochondrial DNA deletions.

Exercise Training

It sounds counterintuitive to prescribe exercise for people whose cells struggle to make energy, but exercise is one of the better-supported interventions for mitochondrial myopathy. A randomized controlled trial had patients do a combination of cycling and upper-body resistance training three days per week. After the training program, participants showed roughly a 29% increase in peak oxygen uptake, a 62% improvement in endurance performance, walked about 95 meters farther on a shuttle test, and gained 32 to 62% more peripheral muscle strength. Quality-of-life scores also improved, while a control group of untrained patients showed no change.¹⁷ The likely explanation is that exercise stimulates the growth of new mitochondria in muscle cells. If a patient’s muscle harbors a mix of healthy and mutated mitochondria, more mitochondria overall means more functional ones doing the work. Exercise programs for mitochondrial patients typically start at a lower intensity than for healthy individuals and scale up gradually under supervision.

NAD+ Boosting Strategies

One of the more exciting recent developments involves boosting levels of NAD+, a molecule central to energy metabolism that appears to be depleted in mitochondrial myopathy. Research has demonstrated that disrupted NAD+ balance is a key part of the disease process in human mitochondrial myopathy, not just in mouse models.¹⁸ Two main supplements are being explored as NAD+ precursors: niacin (vitamin B3) and nicotinamide riboside (NR).

A twin study of nicotinamide riboside showed that NR supplementation improved systemic NAD+ levels, increased the number of mitochondria in muscle, improved muscle stem cell function, and even altered gut bacteria composition.¹⁹ These are encouraging signals, but most of the work so far has been in small studies or specific populations, and NAD+ boosting has not yet been tested in the kind of large controlled trials that would settle the question of whether it meaningfully changes disease outcomes in mitochondrial patients. Still, clinicians are watching this space closely because the biological rationale is strong and the supplements are widely available.

Gene Therapy on the Horizon

Because roughly 90% of mitochondrial diseases trace back to a mutation in a single nuclear gene, they are theoretically good candidates for gene replacement therapy using adeno-associated virus (AAV) vectors, the same delivery system used in approved gene therapies for conditions like spinal muscular atrophy.²⁰ Animal studies have shown strong therapeutic effects from AAV-mediated correction of nuclear-encoded mitochondrial genes.²¹ Several clinical trials are underway or in planning for specific conditions like Leigh syndrome and mitochondrial neurogastrointestinal encephalomyopathy.

For mutations in the mitochondrial DNA itself (the remaining roughly 10%), gene therapy is harder because mitochondria have their own genomes inside a double membrane, and getting therapeutic material through that barrier is a different engineering problem. A separate reproductive strategy, sometimes called mitochondrial replacement therapy or “three-parent babies,” aims to prevent transmission of mitochondrial DNA mutations to the next generation by transferring the nuclear DNA from a mother’s egg into a donor egg with healthy mitochondria.²² This is approved in the United Kingdom and has been performed in a small number of cases, but it prevents disease in future children rather than treating existing patients.

Hypoxia Research

Perhaps the most surprising finding in recent mitochondrial disease research is that low oxygen, normally considered harmful, can be therapeutic. In mouse models of Leigh syndrome, chronic exposure to mildly low oxygen levels (like living at a high altitude) led to dramatic improvements in survival, weight, body temperature, behavior, brain pathology, and disease biomarkers.²³ The effect was large enough to generate real excitement, and subsequent work has extended the finding to additional mitochondrial disease models.²⁴

Obviously, asking patients to live in a low-oxygen environment indefinitely is not practical. Researchers are now working on small molecules that mimic the effect of hypoxia at the tissue level, for instance by increasing how tightly hemoglobin holds onto oxygen so that less is released to the tissues. This is still firmly in the preclinical stage, and it is unclear whether the dramatic benefits seen in mice will translate to humans. But the conceptual insight that reducing oxygen delivery, rather than increasing it, might help when the mitochondrial machinery that uses oxygen is broken is one of those findings that has genuinely shifted how the field thinks about treatment.

Tracking Whether Treatment Is Working

One of the practical challenges of mitochondrial disease is knowing whether a treatment is actually helping. Symptoms fluctuate day to day, disease progression is slow and variable, and many patients are on multiple interventions at once. Blood-based biomarkers are becoming increasingly useful for this. Two proteins, FGF21 and GDF15, are released into the bloodstream in higher amounts when mitochondrial function is impaired. In a comparison study, these biomarkers detected mitochondrial disease in about 62% of genetically confirmed patients, compared to only 39% picked up by the traditional muscle biopsy.²⁵ In children, FGF21 levels correlated with disease severity scores, and both markers tracked with multisystem involvement and critical illness.²⁶ Normal biomarker levels do not rule out mitochondrial disease, especially when the disease does not primarily affect muscle, but the combination of FGF21 and GDF15 is increasingly recommended as a first-line blood test alongside or even before muscle biopsy.²⁵

Why Progress Has Been Slow

If the biological understanding is advancing, why are so few treatments approved? The obstacles are structural. Mitochondrial diseases are genetically and clinically diverse: hundreds of different gene mutations cause overlapping but distinct syndromes, which makes it hard to assemble large, homogeneous patient groups for clinical trials. Patients are geographically scattered, and there are no widely validated endpoints that regulators and researchers agree on for measuring treatment success. Several well-designed late-stage trials have produced negative or inconclusive results, often because the study was too small or too short to detect a real effect.²⁷ The FDA has recognized that standard trial designs built for common diseases often do not work for rare conditions and has created programs like Orphan Drug, Fast Track, and Rare Pediatric Disease designations to help.²⁸ Better biomarkers, more sophisticated adaptive trial designs, and natural history registries that document how untreated disease progresses are all helping to move the needle, but the field is still catching up to its own scientific insights.

Mitophagy and Clearing Out Damaged Mitochondria

A newer therapeutic concept focuses not on fixing broken mitochondria but on getting rid of them. Mitophagy is the cell’s built-in quality-control system for selectively destroying damaged mitochondria while sparing healthy ones. In many mitochondrial diseases, a patient’s cells carry a mix of normal and mutated mitochondria, and the severity of symptoms often tracks directly with the percentage of mutated copies. If you could tip the balance by accelerating the destruction of the bad mitochondria, you might reduce symptoms without ever correcting the underlying mutation.²⁹ The idea is elegant, but suitable drugs that selectively and safely ramp up mitophagy in humans do not yet exist. Candidate compounds have shown promise in cell and animal models, and the approach has enough theoretical backing that several research groups are actively pursuing it. For patients, this is a concept to be aware of rather than something available in the clinic today.