Dimethyl Fumarate
Generic name: dimethyl fumarate · Brand names: Dimethyl Fumarate
Information sourced from FDA Structured Product Labeling, updated June 3, 2026.
What is it used for?
Dimethyl fumarate delayed-release capsules are indicated for the treatment of relapsing forms of multiple sclerosis (MS), to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, in adults. Dimethyl fumarate delayed-release capsules are indicated for the treatment of relapsing forms of multiple sclerosis (MS), to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, in adults.
How to take it
Starting dose: 120 mg twice a day, orally, for 7 days Maintenance dose after 7 days: 240 mg twice a day, orally Swallow dimethyl fumarate delayed-release capsules whole and intact. Do not crush, chew, or sprinkle capsule contents on food Take dimethyl fumarate delayed-release capsules with or without food
Dosing Information The
starting dose for dimethyl fumarate delayed-release capsules is 120 mg twice a day orally. After 7 days, the dose should be increased to the maintenance dose of 240 mg twice a day orally. Temporary dose reductions to 120 mg twice a day may be considered for individuals who do not tolerate the maintenance dose.
Within 4 weeks, the recommended dose of 240 mg twice a day should be resumed. Discontinuation of dimethyl fumarate delayed-release capsules should be considered for patients unable to tolerate return to the maintenance dose. The incidence of flushing may be reduced by administration of dimethyl fumarate delayed-release capsules with food.
Alternatively, administration of non-enteric coated aspirin (up to a dose of 325 mg) 30 minutes prior to dimethyl fumarate delayed-release capsules dosing may reduce the incidence or severity of flushing . Dimethyl fumarate delayed-release capsules should be swallowed whole and intact. Dimethyl fumarate delayed-release capsules should not be crushed or chewed, and the capsule contents should not be sprinkled on food. Dimethyl fumarate delayed-release capsules can be taken with or without food.
Blood Tests Prior to Initiation of Therapy
Obtain a complete blood cell count (CBC) including lymphocyte count before initiation of therapy . Obtain serum aminotransferase, alkaline phosphatase, and total bilirubin levels prior to treatment with dimethyl fumarate delayed-release capsules .
Warnings
Anaphylaxis and Angioedema: Discontinue and do not restart dimethyl fumarate delayed-release capsules if these occur. Progressive Multifocal Leukoencephalopathy (PML): Withhold dimethyl fumarate delayed-release capsules at the first sign or symptom suggestive of PML. Herpes Zoster and Other Serious Opportunistic Infections: Consider withholding dimethyl fumarate delayed-release capsules in cases of serious infection until the infection has resolved. Lymphopenia: Obtain a CBC including lymphocyte count before initiating dimethyl fumarate delayed-release capsules, after 6 months, and every 6 to 12 months thereafter. Consider interruption of dimethyl fumarate delayed-release capsules if lymphocyte counts <0.5 x 10 9 /L persist for more than 6 months. Liver Injury: Obtain serum aminotransferase, alkaline phosphatase, and total bilirubin levels before initiating dimethyl fumarate delayed-release capsules and during treatment, as clinically indicated. Discontinue dimethyl fumarate delayed-release capsules if clinically significant liver injury induced by dimethyl fumarate delayed-release capsules are suspected.
Anaphylaxis and Angioedema Dimethyl
fumarate delayed-release capsules can cause anaphylaxis and angioedema after the first dose or at any time during treatment. Signs and symptoms have included difficulty breathing, urticaria, and swelling of the throat and tongue. Patients should be instructed to discontinue dimethyl fumarate delayed-release capsules and seek immediate medical care should they experience signs and symptoms of anaphylaxis or angioedema.
Progressive Multifocal Leukoencephalopathy Progressive
multifocal leukoencephalopathy (PML) has occurred in patients with MS treated with dimethyl fumarate delayed-release capsules. PML is an opportunistic viral infection of the brain caused by the JC virus (JCV) that typically only occurs in patients who are immunocompromised, and that usually leads to death or severe disability. A fatal case of PML occurred in a patient who received dimethyl fumarate delayed-release capsules for 4 years while enrolled in a clinical trial.
During the clinical trial, the patient experienced prolonged lymphopenia (lymphocyte counts predominantly <0.5x10 9 /L for 3.5 years) while taking dimethyl fumarate delayed-release capsules . The patient had no other identified systemic medical conditions resulting in compromised immune system function and had not previously been treated with natalizumab, which has a known association with PML. The patient was also not taking any immunosuppressive or immunomodulatory medications concomitantly. PML has also occurred in the postmarketing setting in the presence of lymphopenia (<0.9x10 9 /L). While the role of lymphopenia in these cases is uncertain, the PML cases have occurred predominantly in patients with lymphocyte counts <0.8x10 9 /L persisting for more than 6 months.
At the first sign or symptom suggestive of PML, withhold dimethyl fumarate delayed-release capsules and perform an appropriate diagnostic evaluation. Typical symptoms associated with PML are diverse, progress over days to weeks, and include progressive weakness on one side of the body or clumsiness of limbs, disturbance of vision, and changes in thinking, memory, and orientation leading to confusion and personality changes. MRI findings may be apparent before clinical signs or symptoms.
Cases of PML, diagnosed based on MRI findings and the detection of JCV DNA in the cerebrospinal fluid in the absence of clinical signs or symptoms specific to PML, have been reported in patients treated with other MS medications associated with PML. Many of these patients subsequently became symptomatic with PML. Therefore, monitoring with MRI for signs that may be consistent with PML may be useful, and any suspicious findings should lead to further investigation to allow for an early diagnosis of PML, if present. Lower PML-related mortality and morbidity have been reported following discontinuation of another MS medication associated with PML in patients with PML who were initially asymptomatic compared to patients with PML who had characteristic clinical signs and symptoms at diagnosis. It is not known whether these differences are due to early detection and discontinuation of MS treatment or due to differences in disease in these patients.
Herpes Zoster and Other Serious Opportunistic
Infections Serious cases of herpes zoster have occurred with dimethyl fumarate delayed-release capsules, including disseminated herpes zoster, herpes zoster ophthalmicus, herpes zoster meningoencephalitis, and herpes zoster meningomyelitis. These events may occur at any time during treatment. Monitor patients on dimethyl fumarate delayed-release capsules for signs and symptoms of herpes zoster.
If herpes zoster occurs, appropriate treatment for herpes zoster should be administered. Other serious opportunistic infections have occurred with dimethyl fumarate delayed-release capsules, including cases of serious viral (herpes simplex virus, West Nile virus, cytomegalovirus), fungal (Candida and Aspergillus), and bacterial (Nocardia, Listeria monocytogenes, Mycobacterium tuberculosis) infections. These infections have been reported in patients with reduced absolute lymphocyte counts (ALC) as well as in patients with normal ALC. These infections have affected the brain, meninges, spinal cord, gastrointestinal tract, lungs, skin, eye, and ear.
Patients with symptoms and signs consistent with any of these infections should undergo prompt diagnostic evaluation and receive appropriate treatment. Consider withholding dimethyl fumarate delayed-release capsules treatment in patients with herpes zoster or other serious infections until the infection has resolved .
Lymphopenia Dimethyl
fumarate delayed-release capsules may decrease lymphocyte counts. In the MS placebo-controlled trials, mean lymphocyte counts decreased by approximately 30% during the first year of treatment with dimethyl fumarate delayed-release capsules and then remained stable. Four weeks after stopping dimethyl fumarate delayed-release capsules, mean lymphocyte counts increased but did not return to baseline.
Six percent (6%) of dimethyl fumarate delayed-release capsules patients and <1% of placebo patients experienced lymphocyte counts <0.5x10 9 /L (lower limit of normal 0.91x10 9 /L). The incidence of infections (60% vs 58%) and serious infections (2% vs 2%) was similar in patients treated with dimethyl fumarate delayed-release capsules or placebo, respectively. There was no increased incidence of serious infections observed in patients with lymphocyte counts <0.8x10 9 /L or ≤0.5x10 9 /L in controlled trials, although one patient in an extension study developed PML in the setting of prolonged lymphopenia (lymphocyte counts predominantly <0.5x10 9 /L for 3.5 years) . In controlled and uncontrolled clinical trials, 2% of patients experienced prolonged, severe lymphopenia, (defined as lymphocyte counts <0.5 x 10 9 /L for at least six months); in this group of patients, the majority of lymphocyte counts remained <0.5x10 9 /L with continued therapy.
In these patients with prolonged, severe lymphopenia, the median time for lymphocyte counts to return to normal after discontinuing dimethyl fumarate delayed-release capsules was 96.0 weeks. In these controlled and uncontrolled clinical studies, among patients who did not experience prolonged, severe lymphopenia during treatment, the median times for lymphocyte counts to return to normal after discontinuing dimethyl fumarate delayed-release capsules were as follows: 4.3 weeks in patients with mild lymphopenia (lymphocyte count ≥0.8x10 9 /L) at discontinuation, 10.0 weeks in patients with moderate lymphopenia (lymphocyte count 0.5 to <0.8x10 9 /L) at discontinuation, and 16.7 weeks in patients with severe lymphopenia (lymphocyte count <0.5x10 9 /L) at discontinuation. Dimethyl fumarate delayed-release capsules have not been studied in patients with pre-existing low lymphocyte counts.
Obtain a CBC, including lymphocyte count, before initiating treatment with dimethyl fumarate delayed-release capsules, 6 months after starting treatment, and then every 6 to 12 months thereafter, and as clinically indicated. Consider interruption of dimethyl fumarate delayed-release capsules in patients with lymphocyte counts less than 0.5 x 10 9 /L persisting for more than six months. Given the potential for delayed recovery of lymphocyte counts, continue to obtain lymphocyte counts until their recovery if dimethyl fumarate delayed-release capsules are discontinued or interrupted due to lymphopenia.
Consider withholding treatment from patients with serious infections until resolution. Decisions about whether or not to restart dimethyl fumarate delayed-release capsules should be individualized based on clinical circumstances.
Liver Injury Clinically
significant cases of liver injury have been reported in patients treated with dimethyl fumarate delayed-release capsules in the postmarketing setting. The onset has ranged from a few days to several months after initiation of treatment with dimethyl fumarate delayed-release capsules. Signs and symptoms of liver injury, including elevation of serum aminotransferases to greater than 5-fold the upper limit of normal and elevation of total bilirubin to greater than 2-fold the upper limit of normal have been observed.
These abnormalities resolved upon treatment discontinuation. Some cases required hospitalization. None of the reported cases resulted in liver failure, liver transplant, or death. However, the combination of new serum aminotransferase elevations with increased levels of bilirubin caused by drug-induced hepatocellular injury is an important predictor of serious liver injury that may lead to acute liver failure, liver transplant, or death in some patients.
Elevations of hepatic transaminases (most no greater than 3 times the upper limit of normal) were observed during controlled trials . Obtain serum aminotransferase, alkaline phosphatase (ALP), and total bilirubin levels prior to treatment with dimethyl fumarate delayed-release capsules and during treatment, as clinically indicated. Discontinue dimethyl fumarate delayed-release capsules if clinically significant liver injury induced by dimethyl fumarate delayed-release capsules are suspected.
Flushing Dimethyl
fumarate delayed-release capsules may cause flushing (e.g., warmth, redness, itching, and/or burning sensation). In clinical trials, 40% of dimethyl fumarate delayed-release capsules treated patients experienced flushing. Flushing symptoms generally began soon after initiating dimethyl fumarate delayed-release capsules and usually improved or resolved over time.
In the majority of patients who experienced flushing, it was mild or moderate in severity. Three percent (3%) of patients discontinued dimethyl fumarate delayed-release capsules for flushing and <1% had serious flushing symptoms that were not life-threatening but led to hospitalization. Administration of dimethyl fumarate delayed-release capsules with food may reduce the incidence of flushing.
Alternatively, administration of non-enteric coated aspirin (up to a dose of 325 mg) 30 minutes prior to dimethyl fumarate delayed-release capsules dosing may reduce the incidence or severity of flushing .
Serious Gastrointestinal Reactions Serious
gastrointestinal reactions, including perforation, ulceration, hemorrhage, and obstruction, some with fatal outcomes, have been reported in the postmarketing setting with the use of fumaric acid esters, including dimethyl fumarate delayed-release capsules, with or without concomitant aspirin use. The majority of these events have occurred within 6 months of fumaric acid ester treatment initiation. In controlled clinical trials, the incidence ofserious gastrointestinal adverse events was 1% in patients treated with dimethyl fumarate delayed-release capsules; these events, none of which were fatal, included vomiting (0.3%) and abdominal pain (0.3%) . Monitor patients, promptly evaluate, and discontinue dimethyl fumarate delayed-release capsules for new or worsening severe gastrointestinal signs and symptoms.
Who should not take it
Dimethyl fumarate delayed-release capsules are contraindicated in patients with known hypersensitivity to dimethyl fumarate or to any of the excipients of dimethyl fumarate delayed-release capsules. Reactions have included anaphylaxis and angioedema . Known hypersensitivity to dimethyl fumarate or any of the excipients of dimethyl fumarate delayed-release capsules.
Pregnancy
Pregnancy Risk Summary Available
data from the dimethyl fumarate delayed-release capsules Pregnancy Registry, observational studies, and pharmacovigilance with dimethyl fumarate use in pregnant women have not indicated an increased risk of major birth defects, miscarriage, or other adverse maternal or fetal outcomes. Most of the reported exposures to dimethyl fumarate occurred during the first trimester of pregnancy . In animals, adverse effects on offspring survival, growth, sexual maturation, and neurobehavioral function were observed when dimethyl fumarate (DMF) was administered during pregnancy and lactation at clinically relevant doses . The background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes.
In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Data Human Data In a prospective observational dimethyl fumarate delayed-release capsules Pregnancy Registry (2013 to 2022), the rate of major birth defects among 362 live births and stillbirths from women who were exposed to dimethyl fumarate during pregnancy was 3.6% (95% CI: 1.9 to 6.1). No specific pattern of major birth defects was identified.
Important potential study limitations include exposure misclassification, no adjustment for confounders, and lack of an internal comparator cohort. Animal Data In rats administered DMF orally (25, 100, 250 mg/kg/day) throughout organogenesis, embryofetal toxicity (reduced fetal body weight and delayed ossification) were observed at the highest dose tested. This dose also produced evidence of maternal toxicity (reduced body weight).
Plasma exposure (AUC) for monomethyl fumarate (MMF), the major circulating metabolite, at the no-effect dose is approximately three times that in humans at the recommended human dose (RHD) of 480 mg/day. In rabbits administered DMF orally (25, 75, and 150 mg/kg/day) throughout organogenesis, embryolethality and decreased maternal body weight were observed at the highest dose tested. The plasma AUC for MMF at the no-effect dose is approximately 5 times that in humans at the RHD. Oral administration of DMF (25, 100, and 250 mg/kg/day) to rats throughout organogenesis and lactation resulted in increased lethality, persistent reductions in body weight, delayed sexual maturation (male and female pups), and reduced testicular weight at the highest dose tested.
Neurobehavioral impairment was observed at all doses. A no-effect dose for developmental toxicity was not identified. The lowest dose tested was associated with plasma AUC for MMF lower than that in humans at the RHD.
Side effects
The following important adverse reactions are described elsewhere in labeling: Anaphylaxis and Angioedema Progressive multifocal leukoencephalopathy Herpes Zoster and Other Serious Opportunistic Infections Lymphopenia Liver Injury Flushing Serious Gastrointestinal Reactions Most common adverse reactions (incidence ≥10% and ≥2% placebo) were flushing, abdominal pain, diarrhea, and nausea. To report SUSPECTED ADVERSE REACTIONS, contact Aurobindo Pharma USA, Inc. at 1-866-850-2876 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.
Clinical Trials Experience Because
clinical trials are conducted under widely varying conditions, adverse reaction rates observed in clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. In placebo-controlled and uncontrolled clinical studies, a total of 2513 patients have received dimethyl fumarate delayed-release capsules and been followed for periods up to 13 years with an overall exposure of 11,318 person-years. Approximately 1169 patients have received more than 5 years of treatment with dimethyl fumarate delayed-release capsules, and 426 patients have received at least 10 years of treatment with dimethyl fumarate delayed-release capsules.
Adverse Reactions in Placebo-Controlled Trials In the two well-controlled studies demonstrating effectiveness, 1529 patients received dimethyl fumarate delayed-release capsules with an overall exposure of 2244 person-years . The adverse reactions presented in the table below are based on safety information from 769 patients treated with dimethyl fumarate delayed-release capsules 240 mg twice a day and 771 placebo-treated patients. The most common adverse reactions (incidence ≥10% and ≥2% more than placebo) for dimethyl fumarate delayed-release capsules were flushing, abdominal pain, diarrhea, and nausea. Table 1: Adverse Reactions in Study 1 and 2 reported for Dimethyl Fumarate Delayed-Release Capsules 240 mg BID at ≥ 2% higher incidence than placebo Dimethyl Fumarate Delayed-Release Capsules N=769 % Placebo N=771 % Flushing 40 6 Abdominal pain 18 10 Diarrhea 14 11 Nausea 12 9 Vomiting 9 5 Pruritus 8 4 Rash 8 3 Albumin urine present 6 4 Erythema 5 1 Dyspepsia 5 3 Aspartate aminotransferase increased 4 2 Lymphopenia 2 <1 Gastrointestinal Dimethyl fumarate delayed-release capsules caused GI events (e.g., nausea, vomiting, diarrhea, abdominal pain, and dyspepsia).
The incidence of GI events was higher early in the course of treatment (primarily in month 1) and usually decreased over time in patients treated with dimethyl fumarate delayed-release capsules compared with placebo. Four percent (4%) of patients treated with dimethyl fumarate delayed-release capsules and less than 1% of placebo patients discontinued due to gastrointestinal events. The incidence of serious GI events was 1% in clinical trial patients treated with dimethyl fumarate delayed-release capsules; these events, none of which were fatal, included vomiting (0.3%) and abdominal pain (0.3%).
Hepatic Transaminases An increased incidence of elevations of hepatic transaminases in patients treated with dimethyl fumarate delayed-release capsules was seen primarily during the first six months of treatment, and most patients with elevations had levels < 3 times the upper limit of normal (ULN) during controlled trials. Elevations of alanine aminotransferase and aspartate aminotransferase to ≥ 3 times the ULN occurred in a small number of patients treated with both dimethyl fumarate delayed-release capsules and placebo and were balanced between groups. There were no elevations in transaminases ≥ 3 times the ULN with concomitant elevations in total bilirubin > 2 times the ULN. Discontinuations due to elevated hepatic transaminases were < 1% and were similar in patients treated with dimethyl fumarate delayed-release capsules or placebo.
Eosinophilia A transient increase in mean eosinophil counts was seen during the first 2 months of therapy.
Postmarketing Experience The
following adverse reactions have been identified during post-approval use of dimethyl fumarate delayed-release capsules. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Gastrointestinal Disorders: Acute Pancreatitis; Gastrointestinal perforation, ulceration, obstruction, and hemorrhage Hepatobiliary Disorders: Liver function abnormalities (elevations in transaminases ≥ 3 times ULN with concomitant elevations in total bilirubin > 2 times ULN) Infections and Infestations: Herpes zoster infection and other serious opportunistic infections Respiratory, Thoracic, and Mediastinal Disorders: Rhinorrhea Skin and Subcutaneous: Alopecia
All information on this site is provided “as-is” for informational purposes only and is not a substitute for medical advice or treatment. You should consult with a medical professional if you have any questions about your health. Source: FDA Structured Product Labeling.