Dimethyl Fumarate Mylan
Oral disease-modifying therapy for relapsing-remitting multiple sclerosis
Quick Facts: Dimethyl Fumarate Mylan
Key Takeaways
- Treats relapsing-remitting MS: Dimethyl fumarate Mylan reduces relapse rates and MRI lesion activity in patients aged 13 and older with RRMS
- Gradual dose titration required: Start at 120 mg twice daily for the first 7 days, then increase to 240 mg twice daily to minimise side effects
- Regular blood monitoring is essential: Your doctor must check white blood cell counts before and during treatment due to the risk of lymphopenia and infections
- Flushing and GI symptoms are common but temporary: Taking the medicine with food significantly reduces the most frequent side effects
- Serious but rare risk of PML: Progressive multifocal leukoencephalopathy is a rare brain infection that can occur with prolonged lymphocyte suppression — report any new neurological symptoms immediately
What Is Dimethyl Fumarate Mylan and What Is It Used For?
Dimethyl fumarate Mylan is an oral disease-modifying therapy (DMT) containing the active substance dimethyl fumarate. It is approved for the treatment of relapsing-remitting multiple sclerosis (RRMS) in adolescents aged 13 years and older and in adults. It works by modulating the immune system and activating protective antioxidant pathways in the central nervous system.
Multiple sclerosis (MS) is a chronic autoimmune disease that affects the central nervous system (CNS), including the brain and spinal cord. In relapsing-remitting MS — the most common form of the disease — patients experience repeated episodes (relapses) of neurological symptoms. These symptoms vary between individuals but typically include difficulty walking, impaired balance, visual disturbances (such as blurred vision or double vision), numbness, tingling, and fatigue. While some symptoms resolve completely after a relapse, others may persist and gradually accumulate over time.
Dimethyl fumarate Mylan belongs to a class of drugs known as disease-modifying therapies. Unlike symptomatic treatments that only address individual MS symptoms, disease-modifying therapies target the underlying disease process. Dimethyl fumarate appears to work through two main mechanisms. First, it activates the nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, a key antioxidant response pathway that protects cells from oxidative damage. Second, it has immunomodulatory effects, shifting the balance of immune cells from pro-inflammatory to anti-inflammatory profiles. This dual mechanism helps prevent the immune system from attacking the protective myelin sheath around nerve fibres in the brain and spinal cord.
Clinical trials have demonstrated that dimethyl fumarate significantly reduces the annualised relapse rate by approximately 44–53% compared to placebo. It also reduces the number and volume of new brain lesions visible on MRI scans. The landmark DEFINE and CONFIRM trials, published in the New England Journal of Medicine, established dimethyl fumarate as an effective first-line treatment option for RRMS. More recent real-world data have confirmed its long-term efficacy and safety profile over more than 10 years of use.
Dimethyl fumarate Mylan is a generic version of the originator product Tecfidera. The European Medicines Agency (EMA) has confirmed that it is bioequivalent, meaning it contains the same active substance and works in the same way in the body. Other brands containing dimethyl fumarate include Dimethyl fumarate STADA, Dimethyl fumarate Zentiva, and Skilarence (used for psoriasis at different doses).
What Should You Know Before Taking Dimethyl Fumarate Mylan?
Before starting treatment, your doctor must perform blood tests to check your white blood cell count, kidney function, and liver function. Dimethyl fumarate Mylan is contraindicated in patients with confirmed or suspected progressive multifocal leukoencephalopathy (PML) and in those with known hypersensitivity to the active substance.
Contraindications
You must not take Dimethyl fumarate Mylan if you are allergic (hypersensitive) to dimethyl fumarate or any of the other ingredients listed in the composition section of this article. You must also not take this medicine if you have confirmed progressive multifocal leukoencephalopathy (PML) or if PML is suspected. PML is a rare but serious viral brain infection caused by the JC virus that can occur when the immune system is weakened. It can lead to severe disability or death.
Warnings and Precautions
Dimethyl fumarate Mylan can affect the number of white blood cells in your blood, particularly lymphocytes. Before you begin treatment, your doctor will test your blood to establish a baseline count and check that your kidneys and liver are functioning normally. These tests are repeated at regular intervals during treatment — typically every 6 to 12 months, or more frequently if your lymphocyte counts decrease.
Talk to your doctor before taking Dimethyl fumarate Mylan if you have any of the following conditions:
- Severe kidney disease
- Severe liver disease
- A disease of the stomach or intestine (gastrointestinal disorder)
- A serious active infection (such as pneumonia)
Contact your doctor immediately if you notice worsening of your MS symptoms (such as new weakness or visual changes) or any new neurological symptoms. These could be signs of PML, a rare brain infection that has occurred after 1 to 5 years of treatment with dimethyl fumarate. PML symptoms can resemble an MS relapse and may include weakness on one side of the body, clumsiness, changes in vision, changes in thinking or memory, confusion, personality changes, or speech difficulties lasting more than a few days. PML is a serious condition that can lead to severe disability or be life-threatening.
Herpes zoster (shingles) has been reported during treatment with dimethyl fumarate. In some cases, serious complications have occurred. You should inform your doctor immediately if you suspect you have symptoms of shingles, such as a painful rash of blisters typically appearing on one side of the body or face, along with fever and weakness in the early stages.
A rare but serious kidney condition called Fanconi syndrome has been reported with products containing dimethyl fumarate in combination with other fumaric acid esters used to treat psoriasis. If you notice that you are urinating more than usual, are unusually thirsty and drinking more, have weak muscles, break a bone unexpectedly, or have unexplained aches and pains, talk to your doctor as soon as possible so that this can be investigated further.
Children and Adolescents
Dimethyl fumarate Mylan can be used in adolescents aged 13 years and older with relapsing-remitting MS. The safety profile in adolescents is generally similar to that in adults, although some side effects such as headache, abdominal pain, nausea, vomiting, sore throat, cough, and painful menstrual periods have been reported more frequently in this age group. This medicine should not be given to children under 10 years of age as no data are available for this age group.
Pregnancy and Breastfeeding
There is limited information about the effects of dimethyl fumarate on the unborn child when used during pregnancy. You should not use this medicine if you are pregnant unless you have discussed it with your doctor and the medicine is considered absolutely necessary for your treatment. If you are of childbearing potential, discuss appropriate contraceptive measures with your doctor before starting treatment.
It is not known whether the active substance in dimethyl fumarate is excreted in breast milk. Your doctor will advise whether you should stop breastfeeding or stop using the medicine, weighing the benefit of breastfeeding for the child against the therapeutic benefit for you. This decision should be made on an individual basis.
Driving and Operating Machinery
Dimethyl fumarate Mylan is not expected to affect your ability to drive or use machines. No studies on driving performance have been conducted, but the mechanism of action and known side effect profile suggest no impairment.
How Does Dimethyl Fumarate Mylan Interact with Other Drugs?
Dimethyl fumarate Mylan can interact with other immunosuppressive medicines, live vaccines, nephrotoxic drugs, and alcohol. Always inform your doctor about all medications you are taking, including over-the-counter medicines and supplements.
Drug interactions are an important consideration when starting any new medicine. Dimethyl fumarate is rapidly metabolised in the body to its active metabolite, monomethyl fumarate (MMF), without significant involvement of the cytochrome P450 (CYP) enzyme system. This means it has a relatively low potential for pharmacokinetic drug-drug interactions. However, several clinically relevant interactions exist due to its immunomodulatory effects and gastrointestinal properties.
Always tell your doctor or pharmacist if you are taking, have recently taken, or might take any other medicines. This is particularly important for the drug classes listed below, as combining them with dimethyl fumarate may increase the risk of serious adverse effects or reduce the effectiveness of either treatment.
Major Interactions
| Drug / Drug Class | Interaction | Recommendation |
|---|---|---|
| Other fumaric acid esters | Additive immunosuppressive and gastrointestinal effects; increased risk of lymphopenia | Do not combine; contraindicated |
| Immunosuppressants (e.g. methotrexate, azathioprine, ciclosporin) | Increased risk of severe lymphopenia and infections due to additive immunosuppressive effects | Avoid concurrent use; enhanced blood monitoring if switching from immunosuppressants |
| Other MS disease-modifying therapies | Combined immunomodulatory effects may increase risk of opportunistic infections including PML | Generally avoid; allow adequate washout period when switching between therapies |
| Live vaccines (e.g. MMR, varicella, yellow fever) | Risk of active infection from the vaccine strain due to immunomodulatory effects | Avoid live vaccines during treatment; inactivated vaccines may be used as directed by your doctor |
Other Interactions to Be Aware Of
| Drug / Drug Class | Interaction | Recommendation |
|---|---|---|
| Nephrotoxic drugs (e.g. aminoglycosides, NSAIDs, lithium) | Potential additive kidney effects; increased risk of renal impairment | Use with caution; monitor kidney function regularly |
| Alcohol (>30% ABV spirits) | May increase gastric irritation and risk of gastritis; can worsen flushing | Avoid more than 50 ml of strong spirits within 1 hour before or after taking the medicine |
| Diuretics (“water tablets”) | Potential additive effects on kidney function | Use with caution; monitor renal function |
While live vaccines should be avoided, inactivated (non-live) vaccines can generally be given during treatment. However, the immune response to vaccines may be reduced in patients with low lymphocyte counts. Your doctor will determine which vaccinations are appropriate for you. If possible, ensure your vaccination schedule is up to date before starting dimethyl fumarate treatment.
What Is the Correct Dosage of Dimethyl Fumarate Mylan?
The starting dose is 120 mg twice daily for the first 7 days, followed by the maintenance dose of 240 mg twice daily. Capsules should be swallowed whole with water and taken with food to reduce gastrointestinal side effects.
Always take this medicine exactly as your doctor has instructed. Do not change the dose unless directed to do so by your doctor. The dose titration scheme is designed to minimise the most common side effects, particularly flushing and gastrointestinal discomfort, which tend to be most pronounced during the early weeks of treatment.
Adults
Starting Dose (Days 1–7)
120 mg twice daily (one 120 mg capsule in the morning and one in the evening), taken with food. This lower starting dose helps your body adjust to the medicine and reduces the severity of initial side effects.
Maintenance Dose (Day 8 Onwards)
240 mg twice daily (one 240 mg capsule in the morning and one in the evening), taken with food. This is the recommended long-term dose for the treatment of relapsing-remitting MS.
Children and Adolescents (13 Years and Older)
The dosing regimen for adolescents aged 13 years and older is the same as for adults: 120 mg twice daily for the first week, followed by 240 mg twice daily as the maintenance dose. Children under 10 years of age should not use this medicine. For adolescents aged 10–12 years, the prescribing doctor will determine appropriate dosing based on individual assessment, as data for this age group are limited.
Elderly Patients
No specific dose adjustment is required for elderly patients. However, as kidney and liver function may decline with age, your doctor may wish to monitor your blood values more frequently. Clinical trial data in patients over 55 years of age are limited, so close monitoring is advisable.
Swallow the capsules whole with water. Do not split, crush, dissolve, suck, or chew the capsule, as the gastro-resistant coating protects the medicine from being released too early in the stomach, which could increase certain side effects. Taking the capsule with food — particularly food containing some fat — can significantly help reduce flushing and stomach-related side effects.
Missed Dose
If you miss a dose, do not take a double dose to make up for it. You may take the missed dose if at least 4 hours remain between doses. Otherwise, wait until your next scheduled dose and continue your regular dosing schedule. Maintaining a consistent routine — taking doses at approximately the same times each day — can help you remember and reduce the risk of side effects.
Overdose
If you have taken more capsules than prescribed, contact your doctor or nearest emergency department immediately. Symptoms of overdose may be similar to the common side effects described below but could be more severe. There is no specific antidote for dimethyl fumarate overdose; treatment is supportive and symptomatic. If in doubt, always seek medical advice.
What Are the Side Effects of Dimethyl Fumarate Mylan?
Like all medicines, dimethyl fumarate can cause side effects, although not everybody gets them. The most common side effects are flushing (redness, warmth, and burning sensation of the skin) and gastrointestinal symptoms including diarrhoea, nausea, and abdominal pain. These effects are typically most pronounced in the first month of treatment and tend to decrease over time.
Dimethyl fumarate can lower the number of lymphocytes (a type of white blood cell) in your blood. A low white blood cell count may increase your risk of infection, including the risk of a rare brain infection called progressive multifocal leukoencephalopathy (PML). PML has occurred after 1 to 5 years of treatment. Your doctor should continue to monitor your white blood cell counts throughout treatment, and you should be vigilant for any potential PML symptoms as described above.
Severe allergic reactions (anaphylaxis): If flushing is accompanied by a red rash or hives, swelling of the face, lips, mouth, or tongue (angioedema), wheezing, difficulty breathing or shortness of breath, dizziness, or loss of consciousness — stop taking the medicine and seek emergency medical help immediately.
Very Common
May affect more than 1 in 10 people
- Flushing (redness of the face or body, feeling of warmth, heat, burning, or itching)
- Diarrhoea (loose stools)
- Nausea
- Abdominal pain or cramping
- Ketones in urine (a natural substance; detected on urine tests)
Common
May affect up to 1 in 10 people
- Inflammation of the intestinal lining (gastroenteritis)
- Vomiting
- Indigestion (dyspepsia)
- Inflammation of the stomach lining (gastritis)
- Gastrointestinal disturbance
- Burning sensation
- Hot flush, feeling of warmth
- Itching of the skin (pruritus)
- Skin rash
- Pink or red patches on the skin (erythema)
- Hair loss (alopecia)
- Low white blood cell count (lymphopenia, leucopenia) — detected on blood tests
- Protein (albumin) in urine — detected on urine tests
- Elevated liver enzymes (ALT, AST) — detected on blood tests
Uncommon
May affect up to 1 in 100 people
- Allergic reactions (hypersensitivity)
- Decreased platelet count
Rare
May affect up to 1 in 1,000 people
- Liver inflammation (hepatitis) with elevated liver enzymes (ALT or AST combined with bilirubin)
Not Known
Frequency cannot be estimated from available data
- Herpes zoster (shingles) — painful blisters typically on one side of the body or face, with fever, weakness, numbness, and itching
- Runny nose (rhinorrhoea)
- Severe allergic reactions (anaphylaxis)
- Progressive multifocal leukoencephalopathy (PML)
In adolescents aged 13 years and older, the same side effects apply. However, certain side effects have been reported more frequently in younger patients compared to adults, including headache, abdominal pain or cramping, nausea, vomiting, sore throat, cough, and painful menstrual periods.
Flushing and gastrointestinal symptoms are most common during the first month of treatment and typically diminish significantly after the first 2–3 months. Taking the capsule with food — especially food containing some fat — can substantially reduce these effects. If side effects are bothersome, talk to your doctor, who may consider temporarily reducing your dose back to 120 mg twice daily. Do not reduce the dose on your own without medical advice. Some doctors recommend taking non-enteric-coated aspirin (325 mg) approximately 30 minutes before the dose to help reduce flushing.
How Should You Store Dimethyl Fumarate Mylan?
Store at or below 30°C. Keep the capsules in the original packaging and out of the reach of children. Do not use after the expiry date printed on the blister or container.
Proper storage is essential to ensure the medicine remains effective and safe throughout its shelf life. Dimethyl fumarate Mylan capsules should be stored at a temperature not exceeding 30°C (86°F). There is no need to refrigerate the capsules. Keep them in the original blister pack or plastic container to protect them from moisture and light.
Always check the expiry date (marked as EXP) on the packaging before taking a capsule. The expiry date refers to the last day of the stated month. Do not use the medicine after this date. Do not dispose of medicines via the drainage system or with household waste. Ask your pharmacist about appropriate disposal methods to help protect the environment.
Keep this medicine out of the sight and reach of children. If a child accidentally ingests one or more capsules, contact a healthcare professional immediately or call your local poison control centre for advice.
What Does Dimethyl Fumarate Mylan Contain?
Each capsule contains either 120 mg or 240 mg of the active substance dimethyl fumarate. The gastro-resistant capsules also contain various inactive ingredients to ensure proper drug release and stability.
Active Substance
The active substance is dimethyl fumarate. Each 120 mg capsule contains exactly 120 mg of dimethyl fumarate, and each 240 mg capsule contains 240 mg. Dimethyl fumarate is the methyl ester of fumaric acid and is classified as an immunomodulatory agent used in the treatment of relapsing-remitting multiple sclerosis.
Other Ingredients (Excipients)
The inactive ingredients include: microcrystalline cellulose, croscarmellose sodium, talc, colloidal anhydrous silica, magnesium stearate, triethyl citrate, methacrylic acid-methyl methacrylate copolymer (1:1), methacrylic acid-ethyl acrylate copolymer (1:1) dispersion 30%, gelatin, titanium dioxide (E171), indigo carmine (E132), yellow iron oxide (E172), shellac, propylene glycol, ammonium hydroxide, black iron oxide (E172), and purified water (240 mg capsules only).
Appearance and Pack Sizes
Dimethyl fumarate Mylan 120 mg capsules are blue-green and white, marked with “MYLAN” above “DF 120”, containing white to off-white gastro-resistant granules. Available in blister packs of 14 capsules, unit-dose blisters of 14 capsules, and plastic containers of 14 or 60 capsules.
Dimethyl fumarate Mylan 240 mg capsules are blue-green, marked with “MYLAN” above “DF 240”, containing white to off-white gastro-resistant granules. Available in blister packs of 56 or 168 capsules, unit-dose blisters of 56 or 168 capsules, and plastic containers of 56 or 168 capsules.
This medicine contains less than 1 mmol (23 mg) sodium per capsule, meaning it is essentially sodium-free. This is relevant for patients on a controlled sodium diet.
Frequently Asked Questions
Dimethyl fumarate Mylan is used to treat relapsing-remitting multiple sclerosis (RRMS) in patients aged 13 years and older. It is a disease-modifying therapy that helps reduce the frequency and severity of MS relapses and slows disease progression by modulating the immune system and protecting nerve cells from oxidative damage.
The most common side effects include flushing (redness, warmth, burning sensation of the skin) and gastrointestinal symptoms such as diarrhoea, nausea, abdominal pain, and cramping. These side effects are most frequent during the first month of treatment and typically decrease over time. Taking the medication with food can help reduce these effects significantly.
Start with 120 mg twice daily for the first 7 days, then increase to the maintenance dose of 240 mg twice daily. Swallow capsules whole with water — do not split, crush, dissolve, suck, or chew them. Always take with food to reduce common side effects. Try to take your doses at consistent times each day.
You should avoid consuming more than a small amount (more than 50 ml) of strong alcoholic drinks (more than 30% alcohol by volume, such as spirits) within one hour before or after taking Dimethyl fumarate Mylan. Alcohol can interact with the medication and may cause stomach inflammation (gastritis), particularly in people who are already prone to gastric issues.
Dimethyl fumarate Mylan is a generic version of Tecfidera. Both contain the same active ingredient (dimethyl fumarate) in the same strengths (120 mg and 240 mg). The European Medicines Agency (EMA) has confirmed that Dimethyl fumarate Mylan is bioequivalent to Tecfidera, meaning it works in the same way in the body and has the same therapeutic effect.
Yes, dimethyl fumarate has immunomodulatory effects and can lower the number of lymphocytes (a type of white blood cell). This is why regular blood monitoring is essential during treatment. A significantly reduced lymphocyte count increases the risk of infections, including the rare but serious brain infection PML. Your doctor will check blood counts before starting treatment and at regular intervals throughout.
References
- European Medicines Agency (EMA). Dimethyl fumarate Mylan — Summary of Product Characteristics. Available at: www.ema.europa.eu.
- Gold R, Kappos L, Arnold DL, et al. Placebo-controlled phase 3 study of oral BG-12 for relapsing multiple sclerosis. N Engl J Med. 2012;367(12):1098–1107. doi:10.1056/NEJMoa1114287 (DEFINE trial).
- Fox RJ, Miller DH, Phillips JT, et al. Placebo-controlled phase 3 study of oral BG-12 or glatiramer in multiple sclerosis. N Engl J Med. 2012;367(12):1087–1097. doi:10.1056/NEJMoa1206328 (CONFIRM trial).
- Gold R, Arnold DL, Bar-Or A, et al. Long-term safety and efficacy of dimethyl fumarate for up to 13 years in patients with relapsing-remitting multiple sclerosis: Final ENDORSE study results. Mult Scler. 2022;28(5):801–816.
- Berger JR. Classifying PML risk with disease modifying therapies. Mult Scler Relat Disord. 2017;12:59–63.
- British National Formulary (BNF). Dimethyl fumarate. Available at: bnf.nice.org.uk.
- National Institute for Health and Care Excellence (NICE). Multiple sclerosis in adults: management. NICE guideline [CG186]. Updated 2022.
- World Health Organization (WHO). WHO Model List of Essential Medicines, 23rd List (2023).
- Linker RA, Haghikia A. Dimethyl fumarate in multiple sclerosis: latest developments, evidence and place in therapy. Ther Adv Chronic Dis. 2016;7(4):198–207.
- Montalban X, Gold R, Thompson AJ, et al. ECTRIMS/EAN guideline on the pharmacological treatment of people with multiple sclerosis. Mult Scler. 2018;24(2):96–120.
About the Medical Editorial Team
This article has been written, reviewed, and fact-checked by the iMedic Medical Editorial Team, a multidisciplinary group of licensed physicians and clinical pharmacologists with expertise in neurology, internal medicine, and pharmacotherapy.
All medical content is written and reviewed by board-certified physicians with clinical experience in the relevant specialty. Our editorial process follows the GRADE evidence framework to ensure accuracy and clinical relevance.
iMedic receives no commercial funding from pharmaceutical companies. All content is editorially independent. We declare no conflicts of interest in the creation of this article.
Sources consulted: European Medicines Agency (EMA), U.S. Food and Drug Administration (FDA), British National Formulary (BNF), World Health Organization (WHO), National Institute for Health and Care Excellence (NICE), and peer-reviewed journals including the New England Journal of Medicine and Multiple Sclerosis Journal.
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