Dimethyl Fumarate Sandoz: Uses, Dosage & Side Effects
An oral immunomodulatory therapy for the treatment of relapsing-remitting multiple sclerosis in adults
Dimethyl fumarate Sandoz is a prescription oral disease-modifying therapy (DMT) used for the treatment of relapsing-remitting multiple sclerosis (RRMS) in adults. It contains the active substance dimethyl fumarate, which works by activating the Nrf2 antioxidant pathway and modulating the immune system to reduce inflammation and protect nerve cells. Dimethyl fumarate Sandoz is a generic version of Tecfidera, the original brand product. Taken as gastro-resistant capsules twice daily, it has been shown in large clinical trials to significantly reduce the frequency of relapses, slow disability progression, and decrease the number of new or enlarging brain lesions visible on MRI. The most common side effects are flushing and gastrointestinal symptoms, which typically diminish during the first months of treatment.
Quick Facts: Dimethyl Fumarate Sandoz
Key Takeaways
- Dimethyl fumarate Sandoz is an oral disease-modifying therapy for relapsing-remitting multiple sclerosis (RRMS) in adults, providing a convenient twice-daily capsule alternative to injectable or infusion-based MS treatments.
- It works through a dual mechanism: activating the Nrf2 antioxidant pathway for neuroprotection and modulating the immune system to reduce the inflammatory attacks that damage the central nervous system in MS.
- In pivotal clinical trials (DEFINE and CONFIRM), dimethyl fumarate reduced annualized relapse rates by approximately 44–53% compared with placebo, and significantly reduced new or enlarging brain lesions on MRI.
- Regular blood monitoring is essential, as dimethyl fumarate can cause lymphopenia (low lymphocyte counts). A complete blood count should be obtained before starting and every 6–12 months during treatment.
- Flushing and gastrointestinal symptoms (nausea, diarrhea, abdominal pain) are the most common side effects but typically improve within the first 2–3 months of treatment, especially when taken with food.
What Is Dimethyl Fumarate Sandoz and What Is It Used For?
Dimethyl fumarate Sandoz contains the active substance dimethyl fumarate (DMF), a fumaric acid ester that has been developed as a disease-modifying therapy for multiple sclerosis. Multiple sclerosis is a chronic autoimmune disease of the central nervous system (CNS) in which the body's immune system mistakenly attacks the myelin sheath, the protective covering around nerve fibers in the brain, spinal cord, and optic nerves. This immune-mediated damage leads to inflammation, demyelination, and ultimately neurodegeneration, resulting in a wide range of neurological symptoms including fatigue, numbness, weakness, visual disturbances, cognitive difficulties, and impaired coordination.
The relapsing-remitting form of MS (RRMS) is the most common subtype, affecting approximately 85% of newly diagnosed MS patients. RRMS is characterized by clearly defined episodes of new or worsening neurological symptoms (relapses or flare-ups) followed by periods of partial or complete recovery (remissions). Over time, if untreated, many patients with RRMS will develop progressive disability. Disease-modifying therapies like dimethyl fumarate aim to reduce the frequency and severity of relapses, slow the accumulation of disability, and decrease inflammatory activity in the brain as measured by MRI.
Dimethyl fumarate exerts its therapeutic effects through a unique dual mechanism of action. The primary mechanism involves activation of the Nuclear factor erythroid 2-related factor 2 (Nrf2) transcriptional pathway, a key regulator of cellular antioxidant and cytoprotective responses. When dimethyl fumarate is metabolized in the body, its active metabolite monomethyl fumarate (MMF) modifies specific cysteine residues on the Nrf2 inhibitor protein Keap1. This modification releases Nrf2 from its inhibitor, allowing it to translocate to the nucleus where it binds to antioxidant response elements (ARE) in the DNA and activates the transcription of numerous cytoprotective genes. These genes encode enzymes such as heme oxygenase-1 (HO-1), NAD(P)H quinone dehydrogenase 1 (NQO1), and glutathione S-transferase, which collectively protect cells against oxidative stress, a major contributor to neurodegeneration in MS.
The second mechanism of dimethyl fumarate involves modulation of the immune system. It shifts the balance of immune responses from a pro-inflammatory profile dominated by Th1 and Th17 cells toward an anti-inflammatory profile with increased Th2 cytokine production and expansion of regulatory T cells. Dimethyl fumarate also promotes apoptosis (programmed cell death) of activated T cells and reduces the overall lymphocyte count, particularly among memory T-cell subsets that are thought to drive the autoimmune attack in MS. Additionally, it has been shown to reduce the activation and infiltration of immune cells into the central nervous system, thereby decreasing inflammation and subsequent myelin damage.
The clinical efficacy of dimethyl fumarate was established in two pivotal phase III randomized, double-blind, placebo-controlled clinical trials:
- DEFINE (Determination of the Efficacy and Safety of Oral Fumarate in Relapsing-Remitting MS): This trial enrolled 1,234 patients with RRMS and evaluated dimethyl fumarate 240 mg given either twice daily or three times daily against placebo over a 2-year period. The twice-daily regimen (the approved dose) reduced the annualized relapse rate by 53% compared with placebo (0.17 vs. 0.36; p < 0.001). The proportion of patients who relapsed over 2 years was reduced by 49%. Dimethyl fumarate also significantly reduced the risk of sustained disability progression at 12 weeks by 38% (p = 0.01) and dramatically decreased the number of new or enlarging hyperintense lesions on T2-weighted MRI by 85% compared with placebo.
- CONFIRM (Comparator and an Oral Fumarate in Relapsing-Remitting Multiple Sclerosis): This trial enrolled 1,417 patients with RRMS and compared dimethyl fumarate 240 mg twice daily and three times daily with placebo and with an active reference comparator, glatiramer acetate (Copaxone). The twice-daily dose reduced the annualized relapse rate by 44% compared with placebo (0.22 vs. 0.40; p < 0.001). The number of new or enlarging T2 lesions was reduced by 71% versus placebo. While the trial was not powered for a head-to-head comparison with glatiramer acetate, the results suggested comparable or superior efficacy of dimethyl fumarate.
Long-term extension studies (ENDORSE) have demonstrated sustained efficacy and a consistent safety profile for dimethyl fumarate over periods exceeding 10 years, providing reassurance about its long-term use. Dimethyl fumarate was first approved as Tecfidera by the FDA in March 2013 and by the EMA in January 2014. Following patent expiration, generic versions including Dimethyl fumarate Sandoz have become available, offering the same therapeutic benefit at reduced cost. Generic medicines must demonstrate bioequivalence to the reference product and meet the same quality standards as verified by regulatory agencies.
Dimethyl fumarate Sandoz is a generic version of Tecfidera (Biogen). Both contain the same active ingredient in the same strengths and dosage forms. Regulatory agencies require generic medicines to demonstrate bioequivalence, meaning the generic product delivers the same amount of active substance to the body at the same rate as the originator. The clinical effects, including efficacy and side effects, are expected to be the same. Your neurologist or pharmacist can advise you if switching between products is appropriate.
What Should You Know Before Taking Dimethyl Fumarate Sandoz?
Contraindications
Dimethyl fumarate Sandoz must not be used if you have a known hypersensitivity (allergy) to dimethyl fumarate or to any of the other ingredients in the capsule formulation. The excipients include microcrystalline cellulose, croscarmellose sodium, talc, colloidal anhydrous silite, magnesium stearate, methacrylic acid-ethyl acrylate copolymer, triethyl citrate, talc, simethicone, sodium laurilsulfate, polysorbate 80, gelatin, titanium dioxide, brilliant blue FCF (E133), and iron oxide yellow (E172). If you have a known allergy to any of these substances, inform your doctor before starting treatment.
Dimethyl fumarate should not be used in patients with suspected or confirmed progressive multifocal leukoencephalopathy (PML), a rare but serious viral brain infection. Treatment should also not be initiated in patients with severe active gastrointestinal disease, as dimethyl fumarate can worsen gastrointestinal symptoms.
Warnings and Precautions
Dimethyl fumarate can significantly lower lymphocyte counts. Prolonged moderate to severe lymphopenia (lymphocyte count below 0.5 × 109/L for more than 6 months) has been associated with rare cases of progressive multifocal leukoencephalopathy (PML), a potentially life-threatening brain infection caused by the JC virus. Complete blood counts must be monitored before treatment initiation and every 6 to 12 months thereafter. Treatment should be interrupted if the lymphocyte count remains below 0.5 × 109/L for more than 6 months.
Before starting treatment with dimethyl fumarate, your neurologist will perform several baseline assessments:
- Complete blood count (CBC) with differential: Lymphocyte counts must be within normal range before starting treatment. Patients with pre-existing low lymphocyte counts should not initiate dimethyl fumarate without careful evaluation of the risks.
- Liver function tests: Elevated liver enzymes (ALT, AST) have been reported with dimethyl fumarate. Liver function should be checked before treatment and periodically during treatment, particularly if clinically indicated.
- Kidney function: Cases of Fanconi syndrome (a disorder of kidney tubular function) have been reported rarely during post-marketing use. Renal function should be assessed at baseline and monitored periodically.
- Recent MRI of the brain: A baseline MRI is recommended to establish a reference point for monitoring disease activity and to rule out any pre-existing conditions.
Flushing is one of the most common side effects and typically occurs during the first month of treatment. It manifests as warmth, redness, itching, or a burning sensation, most commonly of the face, neck, and upper chest. Taking dimethyl fumarate with food and/or taking 325 mg of non-enteric coated aspirin 30 minutes before dosing may reduce flushing. These episodes are generally mild to moderate and decrease over time in most patients.
Additional precautions include monitoring for signs of herpes zoster (shingles) reactivation, which has been reported in patients taking dimethyl fumarate, particularly those with lymphopenia. Patients should be counseled to report any new persistent or worsening neurological symptoms, as these could indicate PML or other serious infections. If PML is suspected, dimethyl fumarate should be withheld immediately and appropriate diagnostic investigations (including MRI and cerebrospinal fluid testing for JC virus DNA) should be performed.
Pregnancy and Breastfeeding
Dimethyl fumarate is not recommended during pregnancy. Animal reproductive toxicity studies have demonstrated adverse effects on fetal development at doses close to those used therapeutically in humans, including reduced fetal weight, delayed ossification, and increased fetal variations. Although no adequate and well-controlled studies have been conducted in pregnant women, the potential risk to the human fetus cannot be excluded. Women of childbearing potential should use effective contraception during treatment and for at least 4 weeks after the last dose.
If pregnancy occurs during treatment, dimethyl fumarate should be discontinued and the patient should be referred to their neurologist for a comprehensive risk-benefit assessment. The decision to continue or discontinue treatment must weigh the potential risks to the fetus against the risk of MS relapses, which can occur during pregnancy and particularly in the postpartum period. Pregnancy registries exist to collect information on outcomes in women exposed to dimethyl fumarate during pregnancy, and patients are encouraged to enroll.
It is not known whether dimethyl fumarate or its metabolite monomethyl fumarate is excreted in human breast milk. A risk to the breastfed infant cannot be excluded. The decision to breastfeed during treatment should be made in consultation with your neurologist, weighing the benefits of breastfeeding for the infant against the therapeutic benefits of dimethyl fumarate for the mother.
Driving and Operating Machinery
Dimethyl fumarate has no known direct effects on the ability to drive or operate machinery. However, MS itself can impair cognitive and motor functions that are important for driving. Patients should be advised to assess their individual response to the medication and their disease-related symptoms before driving or operating potentially dangerous equipment.
How Does Dimethyl Fumarate Sandoz Interact with Other Drugs?
Dimethyl fumarate is rapidly hydrolyzed by esterases in the gastrointestinal tract before reaching the systemic circulation, and its active metabolite monomethyl fumarate (MMF) is further metabolized via the tricarboxylic acid (TCA) cycle rather than through cytochrome P450 (CYP) enzymes. This metabolic profile means that dimethyl fumarate has a low potential for traditional pharmacokinetic drug-drug interactions. No formal clinical drug interaction studies have been conducted with dimethyl fumarate, and population pharmacokinetic analyses from the clinical trial program have not identified clinically significant effects of commonly used concomitant medications on DMF or MMF pharmacokinetics.
Despite the low pharmacokinetic interaction potential, there are several important pharmacodynamic considerations when using dimethyl fumarate alongside other medications:
| Drug / Category | Interaction Type | Clinical Significance | Recommendation |
|---|---|---|---|
| Other MS disease-modifying therapies | Pharmacodynamic (additive immunosuppression) | High | Do not use concurrently; allow adequate washout period when switching |
| Immunosuppressants (azathioprine, methotrexate, ciclosporin) | Pharmacodynamic (additive immunosuppression) | High | Avoid concurrent use; increased risk of infection |
| Live vaccines | Pharmacodynamic (reduced immune response) | High | Avoid during treatment; complete vaccinations before starting |
| Inactivated vaccines | Potentially reduced immune response | Moderate | Can be given; antibody response may be reduced |
| Nephrotoxic drugs (aminoglycosides, NSAIDs) | Potential additive renal effects | Low to moderate | Monitor renal function when co-administered |
| Non-enteric coated aspirin (325 mg) | Beneficial co-administration | Low (positive) | May be taken 30 min before DMF to reduce flushing |
| Oral contraceptives | No interaction identified | None | No dose adjustment needed |
When switching from another MS disease-modifying therapy to dimethyl fumarate, an appropriate washout period must be observed to allow recovery of the immune system before initiating the new treatment. The duration of the washout depends on the half-life and immunological effects of the previous therapy. For example, switching from fingolimod requires monitoring lymphocyte recovery (which can take several months), while switching from interferon beta or glatiramer acetate may require a shorter interval. Your neurologist will determine the appropriate timing for the switch based on your individual clinical situation and blood test results.
Dimethyl fumarate may transiently reduce lymphocyte counts during the first year of treatment, which typically stabilize at a level above the lower limit of normal in most patients. However, approximately 2–6% of patients experience severe and prolonged lymphopenia. Concurrent use of other medications that affect lymphocyte counts or immune function could compound this effect. Always inform your neurologist about all medications, supplements, and herbal products you are taking before starting or during treatment with dimethyl fumarate.
It is recommended that all necessary vaccinations (including varicella-zoster vaccine if non-immune) be completed at least 4–6 weeks before starting dimethyl fumarate. Live attenuated vaccines should not be administered during treatment. Inactivated vaccines (including influenza, COVID-19, and pneumococcal vaccines) can be given during treatment, although the immune response may be somewhat reduced, particularly in patients with lymphopenia. Discuss your vaccination schedule with your neurologist before starting treatment.
What Is the Correct Dosage of Dimethyl Fumarate Sandoz?
Dimethyl fumarate Sandoz should always be used exactly as prescribed by your neurologist. Treatment follows a gradual dose-titration schedule designed to minimize the initial side effects of flushing and gastrointestinal symptoms, which are most pronounced at the start of treatment.
Adults
| Phase | Duration | Morning Dose | Evening Dose | Daily Total |
|---|---|---|---|---|
| Titration | Days 1–7 | 120 mg | 120 mg | 240 mg |
| Maintenance | Day 8 onwards | 240 mg | 240 mg | 480 mg |
The capsules should be swallowed whole with water or another liquid. They must not be crushed, chewed, or opened, as the gastro-resistant coating is designed to protect the active substance from degradation in the stomach acid and to reduce gastrointestinal irritation. Taking the capsules with food (particularly a meal containing some fat or protein) is strongly recommended, as this has been shown in clinical studies to reduce both the incidence and severity of flushing and gastrointestinal side effects by up to 30–40%.
Some neurologists may recommend a more gradual titration schedule for patients who are particularly sensitive to flushing or gastrointestinal effects. This may involve starting with 120 mg once daily for the first week, then 120 mg twice daily for the second week, followed by 240 mg in the morning and 120 mg in the evening for the third week, before reaching the full dose of 240 mg twice daily in the fourth week. Temporary dose reduction to 120 mg twice daily for up to 4 weeks may also be considered for managing persistent side effects, although the long-term efficacy of the reduced dose has not been established.
Children and Adolescents
Dimethyl fumarate is not approved for use in children and adolescents under 18 years of age. The safety and efficacy of dimethyl fumarate in pediatric patients have not been established in controlled clinical trials. Pediatric MS is relatively uncommon and requires specialized management. If your child has been diagnosed with MS, discuss appropriate treatment options with a pediatric neurologist experienced in MS care.
Elderly Patients
Clinical trials of dimethyl fumarate included limited numbers of patients aged 55 years and above, and no patients over 65 years. No dose adjustment is recommended based on age alone. However, elderly patients may have age-related decreases in renal and hepatic function and may be more susceptible to infections. Close monitoring of blood counts and organ function is advisable in older patients starting dimethyl fumarate.
Missed Dose
If you miss a dose of dimethyl fumarate, do not take a double dose to make up for the missed one. If you remember the missed dose and there are still several hours before your next scheduled dose, take the missed dose as soon as you remember. If it is close to the time of your next dose, simply skip the missed dose and continue with your regular dosing schedule. Taking two doses at the same time or in close succession may increase the risk and severity of flushing and gastrointestinal side effects. If you frequently forget doses, consider setting a daily alarm or using a pill organizer.
Overdose
There is limited clinical experience with dimethyl fumarate overdose. In the event of an overdose, standard supportive measures should be implemented. There is no specific antidote for dimethyl fumarate. The active metabolite monomethyl fumarate is dialyzable; however, given the short half-life (approximately 1 hour), the clinical benefit of dialysis in overdose situations is uncertain. Contact your local poison control center or seek emergency medical attention if you suspect an overdose.
Practical Administration Tips
Based on clinical experience and patient feedback, the following strategies can help optimize tolerability when starting dimethyl fumarate:
- Always take with food: A substantial meal (not just a snack) significantly reduces flushing and gastrointestinal symptoms. High-fat and high-protein foods may be particularly helpful.
- Consider aspirin pre-treatment: Taking 325 mg of non-enteric coated aspirin approximately 30 minutes before the dimethyl fumarate dose can substantially reduce the intensity and duration of flushing episodes.
- Take at consistent times: Establishing a routine of taking the capsules at the same times each day (e.g., with breakfast and dinner) helps maintain steady drug levels and improves adherence.
- Be patient with side effects: Flushing and gastrointestinal symptoms are most common during the first 2–4 weeks and typically diminish significantly by the end of the first month. Most patients tolerate the medication well after this initial adjustment period.
- Avoid alcohol with doses: Alcohol may worsen flushing symptoms. If you drink alcohol, try to separate it from your dimethyl fumarate doses by several hours.
What Are the Side Effects of Dimethyl Fumarate Sandoz?
Like all medicines, dimethyl fumarate can cause side effects, although not everybody gets them. The side effect profile of dimethyl fumarate has been well characterized in clinical trials involving more than 2,600 patients and through extensive post-marketing surveillance since its approval in 2013. Understanding the expected side effects and their typical time course can help you and your healthcare team manage them effectively.
The side effects are listed below according to their frequency of occurrence. Frequencies are defined as: very common (affects more than 1 in 10 people), common (affects 1 in 10 to 1 in 100 people), uncommon (affects 1 in 100 to 1 in 1,000 people), and rare (affects fewer than 1 in 1,000 people).
Very Common
Affects more than 1 in 10 people
- Flushing (warmth, redness, itching, or burning sensation of the skin, particularly face and upper body)
- Diarrhea
- Nausea
- Abdominal (stomach) pain or cramping
Common
Affects 1 in 10 to 1 in 100 people
- Vomiting
- Dyspepsia (indigestion)
- Gastritis (inflammation of the stomach lining)
- Gastrointestinal disorder
- Hot flush (feeling of heat)
- Pruritus (itching)
- Rash or erythema (skin redness)
- Lymphopenia (low lymphocyte count)
- Leukopenia (low white blood cell count)
- Elevated liver enzymes (ALT, AST)
- Proteinuria (protein in urine)
- Feeling of burning sensation
- Albumin in urine
Uncommon
Affects 1 in 100 to 1 in 1,000 people
- Herpes zoster (shingles) reactivation
- Lymphocyte count severely decreased (< 0.5 × 109/L)
- Angioedema (swelling of face, lips, or tongue)
- Hypersensitivity reactions
Rare
Affects fewer than 1 in 1,000 people
- Progressive multifocal leukoencephalopathy (PML) – in the setting of prolonged severe lymphopenia
- Anaphylaxis (severe allergic reaction)
- Fanconi syndrome (kidney tubular dysfunction)
- Severe prolonged lymphopenia lasting over 6 months
Flushing and gastrointestinal side effects deserve special attention because they are the most common reasons for treatment discontinuation, particularly during the first few months. In clinical trials, approximately 3% of patients discontinued dimethyl fumarate due to flushing and approximately 4% due to gastrointestinal events. However, these side effects are most intense during the first 2–4 weeks of treatment and typically decline substantially over the first 2–3 months. Among patients who persist with treatment through this initial period, the vast majority find the side effects manageable and tolerable in the long term.
Flushing episodes typically begin within 30–60 minutes of taking the capsule and last for approximately 30–60 minutes, though they can occasionally persist for several hours. The flushing is thought to be mediated by activation of the nicotinic acid receptor GPR109A (also known as hydroxycarboxylic acid receptor 2, HCA2) on Langerhans cells in the skin, leading to prostaglandin D2 release. This mechanism explains why pre-treatment with aspirin (which inhibits prostaglandin synthesis) can effectively reduce flushing severity.
Lymphopenia is a clinically important side effect that requires ongoing monitoring. In the DEFINE and CONFIRM trials, mean lymphocyte counts decreased by approximately 30% during the first year of treatment and then remained stable. Most patients maintain lymphocyte counts above the lower limit of normal (0.91 × 109/L). However, approximately 2–6% of patients develop severe lymphopenia (lymphocyte count below 0.5 × 109/L). Prolonged severe lymphopenia increases the risk of opportunistic infections, including the rare but potentially fatal JC virus-associated PML. For this reason, complete blood counts must be monitored regularly, and treatment should be reconsidered if severe lymphopenia persists beyond 6 months.
Contact your neurologist or seek emergency medical care immediately if you experience: signs of a severe allergic reaction (difficulty breathing, swelling of the face or throat, severe rash or hives); symptoms that could indicate PML (progressive weakness, vision changes, confusion, personality changes, difficulty with speech or walking); signs of severe infection (high fever, persistent cough, painful skin lesions); or severe persistent abdominal pain with bloody diarrhea.
How Should You Store Dimethyl Fumarate Sandoz?
Proper storage of dimethyl fumarate is important to ensure the medication remains effective and safe throughout its shelf life. The gastro-resistant coating on the capsules is sensitive to moisture and light, which can compromise the integrity of the formulation and the protective coating that prevents stomach acid from degrading the active substance.
Follow these storage guidelines:
- Temperature: Store below 30°C (86°F). Do not freeze. The medication should be kept at room temperature, away from direct heat sources such as radiators, stoves, or sunny windowsills.
- Light protection: Keep the capsules in the original blister packaging until ready to use. The blister packs protect the capsules from light and moisture. Do not transfer capsules to a different container.
- Moisture: Avoid storing in humid environments such as bathrooms. The gastro-resistant coating can be affected by excessive moisture.
- Expiration date: Do not use dimethyl fumarate Sandoz after the expiration date printed on the packaging. The expiration date refers to the last day of that month.
- Child safety: Keep this medicine out of the sight and reach of children. Accidental ingestion by children could cause serious side effects.
- Disposal: Do not dispose of medicines via household waste or wastewater. Return unused or expired medication to your pharmacist for proper disposal. This helps protect the environment.
If you notice any visible changes in the appearance of the capsules (such as discoloration, cracking, or an unusual smell), do not take them. Contact your pharmacist for a replacement supply.
What Does Dimethyl Fumarate Sandoz Contain?
Each capsule of Dimethyl fumarate Sandoz contains the following:
| Component | 120 mg Capsule | 240 mg Capsule |
|---|---|---|
| Active substance | Dimethyl fumarate 120 mg | Dimethyl fumarate 240 mg |
| Core excipients | Microcrystalline cellulose, croscarmellose sodium, talc, colloidal anhydrous silica, magnesium stearate | |
| Gastro-resistant coating | Methacrylic acid–ethyl acrylate copolymer, triethyl citrate, talc, simethicone, sodium laurilsulfate, polysorbate 80 | |
| Capsule shell | Gelatin, titanium dioxide (E171), brilliant blue FCF (E133), iron oxide yellow (E172) | Gelatin, titanium dioxide (E171), brilliant blue FCF (E133) |
The 120 mg capsules are typically green and white, while the 240 mg capsules are green in color. Both are hard gelatin capsules containing white to off-white gastro-resistant micro-tablets or gastro-resistant granules. The gastro-resistant coating ensures that the dimethyl fumarate is released in the small intestine rather than the stomach, which helps reduce gastrointestinal irritation and ensures optimal absorption of the active substance.
Dimethyl fumarate itself is a methyl ester of fumaric acid with the molecular formula C6H8O4 and a molecular weight of 144.13 g/mol. It is a white to off-white crystalline powder that is slightly soluble in water. After oral ingestion, dimethyl fumarate is rapidly and presystemically hydrolyzed by esterases in the gastrointestinal tract to its primary active metabolite, monomethyl fumarate (MMF). DMF itself is not quantifiable in plasma after oral administration of standard therapeutic doses, confirming its rapid and complete conversion to MMF before entering the systemic circulation.
Frequently Asked Questions
Dimethyl fumarate Sandoz is a generic version of Tecfidera, the original brand-name product developed by Biogen. Both contain the same active ingredient (dimethyl fumarate) in the same strengths (120 mg and 240 mg) and the same dosage form (gastro-resistant hard capsules). Generic medicines are required by regulatory agencies such as the European Medicines Agency (EMA) to demonstrate bioequivalence to the originator product, meaning they deliver the same amount of active substance at the same rate. The clinical effects, including both efficacy and side effects, are expected to be identical. The primary differences are in brand name, packaging appearance, and typically price, with generics generally being more affordable.
Dimethyl fumarate begins to modulate the immune system within the first weeks of treatment, but its clinical effects on reducing relapses develop gradually. In clinical trials, significant reductions in new MRI lesions were observed within the first 6 months. The full therapeutic effect on relapse rate reduction and disability progression may take 6 to 12 months to become fully apparent. It is important to continue taking the medication consistently even if you do not notice immediate changes, as disease-modifying therapies work by preventing future disease activity rather than treating current symptoms. Your neurologist will typically assess the effectiveness of treatment after 6 to 12 months, using a combination of clinical evaluation and MRI monitoring.
Yes, for the vast majority of patients, flushing and gastrointestinal side effects improve significantly within the first 2 to 3 months of treatment. In clinical trials, the incidence of flushing decreased by approximately 50% after the first month and continued to decline thereafter. Gastrointestinal symptoms followed a similar pattern. Taking the capsules with food, using the recommended dose titration schedule, and optionally taking 325 mg of non-enteric coated aspirin 30 minutes before dosing can all help minimize these effects during the initial adjustment period. Among patients who continue treatment through the first few months, the vast majority find the side effects manageable in the long term.
There is no formal contraindication to moderate alcohol consumption while taking dimethyl fumarate. However, alcohol can worsen flushing symptoms, particularly if consumed close to the time of taking the medication. If you choose to drink alcohol, it is advisable to separate it from your dimethyl fumarate doses by several hours and to drink in moderation. Additionally, excessive alcohol use can affect liver function, and since dimethyl fumarate can occasionally cause elevated liver enzymes, combining heavy alcohol use with the medication may increase the risk of liver-related side effects. Discuss your alcohol consumption with your neurologist.
If your lymphocyte count falls below 0.8 × 109/L, your neurologist will monitor it more frequently (typically every 3 months). If the count drops below 0.5 × 109/L and remains at that level for more than 6 months, treatment with dimethyl fumarate should generally be stopped due to the increased risk of infections, including the rare but serious risk of progressive multifocal leukoencephalopathy (PML). After stopping dimethyl fumarate, lymphocyte counts typically recover over weeks to months, although recovery can take longer in some patients. Your neurologist will discuss alternative MS treatment options with you.
Inactivated vaccines (such as influenza, COVID-19 mRNA vaccines, and pneumococcal vaccines) can be administered during treatment with dimethyl fumarate, although the immune response may be somewhat reduced, particularly in patients with lower lymphocyte counts. Live attenuated vaccines (such as measles-mumps-rubella, varicella, and yellow fever) should be avoided during treatment due to the risk of vaccine-strain infection in immunocompromised patients. It is recommended to complete all necessary vaccinations, including varicella vaccination if you are not immune, at least 4 to 6 weeks before starting dimethyl fumarate. Discuss your vaccination status with your neurologist before initiating treatment.
References
- European Medicines Agency (EMA). Tecfidera (dimethyl fumarate) – Summary of Product Characteristics. Last updated 2025. Available at: EMA Tecfidera EPAR.
- U.S. Food and Drug Administration (FDA). Tecfidera (dimethyl fumarate) – Prescribing Information. Biogen Inc. Revised 2024.
- Gold R, Kappos L, Arnold DL, et al. Placebo-Controlled Phase 3 Study of Oral BG-12 for Relapsing Multiple Sclerosis (DEFINE Study). N Engl J Med. 2012;367(12):1098–1107. doi:10.1056/NEJMoa1114287.
- Fox RJ, Miller DH, Phillips JT, et al. Placebo-Controlled Phase 3 Study of Oral BG-12 or Glatiramer in Multiple Sclerosis (CONFIRM Study). N Engl J Med. 2012;367(12):1087–1097. doi:10.1056/NEJMoa1206328.
- Gold R, Arnold DL, Bar-Or A, et al. Long-term effects of delayed-release dimethyl fumarate in multiple sclerosis: Interim analysis of ENDORSE, a randomized extension study. Mult Scler. 2017;23(2):253–265. doi:10.1177/1352458516649037.
- Montalban X, Gold R, Thompson AJ, et al. ECTRIMS/EAN guideline on the pharmacological treatment of people with relapsing multiple sclerosis. Mult Scler. 2024;30(2):153–175.
- Rae-Grant A, Day GS, Marrie RA, et al. Practice guideline recommendations summary: Disease-modifying therapies for adults with multiple sclerosis. Neurology. 2018;90(17):777–788. doi:10.1212/WNL.0000000000005347.
- Linker RA, Lee DH, Ryan S, et al. Fumaric acid esters exert neuroprotective effects in neuroinflammation via activation of the Nrf2 antioxidant pathway. Brain. 2011;134(3):678–692. doi:10.1093/brain/awq386.
- World Health Organization (WHO). Multiple Sclerosis Fact Sheet. 2023. Available at: WHO Multiple Sclerosis.
- British National Formulary (BNF). Dimethyl fumarate. National Institute for Health and Care Excellence (NICE). 2025.
About Our Medical Team
All content on iMedic is created and reviewed by qualified medical professionals following international evidence-based guidelines. Our editorial process ensures accuracy, currency, and clinical relevance.
Medical Content Team
Specialists in neurology, neuroimmunology, and clinical pharmacology with extensive experience in multiple sclerosis management and disease-modifying therapies.
Medical Review Board
Independent panel of board-certified physicians who verify all medical claims against current evidence and international guidelines (WHO, EMA, FDA, ECTRIMS, AAN).
Editorial Standards
All content follows the GRADE evidence framework and is based on Level 1A evidence from systematic reviews and randomized controlled trials where available.
Independence
iMedic receives no pharmaceutical company funding or sponsorship. All content is editorially independent, ensuring unbiased medical information for patients and caregivers.