Diroximel Fumarate
Diroximel fumarate is a prescription capsule taken by mouth to treat relapsing forms of multiple sclerosis (MS) in adults.
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 1 clinical label set within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
Diroximel fumarate (Vumerity) is a twice-daily capsule for relapsing forms of multiple sclerosis in adults, on the U.S. market since about 2018, that the body turns into monomethyl fumarate, the same active form as the older dimethyl fumarate. Most people manage it well; flushing (warm, red skin) and stomach upset like diarrhea or nausea are the usual complaints, and many find it gentler on the stomach than dimethyl fumarate. Keep up with regular blood tests for low white cell counts and liver problems, and get help fast for face or throat swelling, signs of infection such as shingles, or new neurologic symptoms, which rarely signal PML, a serious brain infection.
Clinical pearls
- Swallow the capsules whole, without crushing, chewing or sprinkling the contents on food.
- Avoid alcohol, and skip high-fat, high-calorie meals or snacks with a dose, since rich food changes how quickly it absorbs.
- A non-enteric coated aspirin taken about 30 minutes before a dose may ease flushing, if your prescriber agrees.
- Never take it with dimethyl fumarate, which shares its active form, though a switch can start the day after dimethyl fumarate stops.
Patient information guide A plain-language walkthrough of Diroximel Fumarate, written from its FDA label.
What Diroximel Fumarate is used for
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Diroximel fumarate is used for one main condition.
- Vumerity treats relapsing forms of multiple sclerosis (MS) in adults.
- This includes clinically isolated syndrome, relapsing-remitting disease and active secondary progressive disease.
How Diroximel Fumarate works
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After you swallow it, diroximel fumarate is quickly changed into monomethyl fumarate (MMF), its active form. How it helps in MS is not known.
MMF turns on the Nrf2 pathway, which helps cells respond to oxidative stress. In lab studies it also acted on a nicotinic acid receptor.
Diroximel Fumarate dosage
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Vumerity is a capsule taken by mouth twice a day. You start with a lower dose for 7 days, then move to the maintenance dose. Follow your prescriber and label for exact dosing.
- Swallow capsules whole. Do not crush, chew or sprinkle on food.
- If you take it with food, avoid high-fat, high-calorie meals or snacks.
- Avoid alcohol.
- If you cannot tolerate the full dose, your prescriber may temporarily lower it and return to the full dose within 4 weeks.
Dosing details from the FDA-approved label
From the Diroximel Fumarate prescribing information (“Dosage and Administration”). Doses are set by your prescriber for your product, condition, kidney function and age — never change a dose on your own.
- Starting dosage (adults)
- 231 mg twice a day orally for 7 days
- Obtain CBC including lymphocyte count, and serum aminotransferase, alkaline phosphatase and total bilirubin levels prior to initiation
- Maintenance dosage (after 7 days)
- 462 mg (administered as two 231 mg capsules) twice a day orally
- Swallow capsules whole and intact; if taken with food, avoid a high-fat, high-calorie meal/snack (no more than 700 calories and no more than 30 g fat); avoid alcohol
- Patients who do not tolerate the maintenance dosage
- Temporary dosage reduction to 231 mg twice a day may be considered
- Within 4 weeks, resume 462 mg twice a day
- Consider discontinuation if patient is unable to tolerate return to the maintenance dosage
- Patients with renal impairment
- No dosing adjustment is recommended in patients with mild renal impairment
- Not recommended in patients with moderate or severe renal impairment
Read the label’s full dosing text
2 DOSAGE AND ADMINISTRATION Blood tests are required prior to initiation of VUMERITY ( 2.1 ) Starting dose: 231 mg twice a day, orally, for 7 days ( 2.2 ) Maintenance dose after 7 days: 462 mg (administered as two 231 mg capsules) twice a day, orally ( 2.2 ) Swallow VUMERITY capsules whole and intact. Do not crush, chew, or sprinkle capsule contents on food ( 2.3 ) Avoid administration of VUMERITY with a high-fat, high-calorie meal/snack ( 2.3 ) Avoid co-administration of VUMERITY with alcohol ( 2.3 ) 2.1 Blood Tests Prior to Initiation of VUMERITY Obtain the following prior to treatment with VUMERITY: A complete blood cell count (CBC), including lymphocyte count [see Warnings and Precautions ( 5.4 )] . Serum aminotransferase, alkaline phosphatase, and total bilirubin levels [see Warnings and Precautions ( 5.5 )] . 2.2 Dosing Information The starting dosage for VUMERITY is 231 mg twice a day orally. After 7 days, the dosage should be increased to the maintenance dosage of 462 mg (administered as two 231 mg capsules) twice a day orally. Temporary dosage reductions to 231 mg twice a day may be considered for individuals who do not tolerate the maintenance dosage. Within 4 weeks, the recommended dosage of 462 mg twice a day should be resumed. Discontinuation of VUMERITY should be considered for patients unable to tolerate return to the maintenance dosage. Administration of non-enteric coated aspirin (up to a dose of 325 mg) 30 minutes prior to VUMERITY dosing may reduce the incidence or severity of flushing [see Clinical Pharmacology ( 12.3 )]. 2.3 Administration Instructions Swallow VUMERITY capsules whole and intact. Do not crush or chew, or sprinkle the capsule contents on food. If taken with food, avoid a high-fat, high-calorie meal/snack; the meal/snack should contain no more than 700 calories and no more than 30 g fat [see Warnings and Precautions ( 5.6 ) and Clinical Pharmacology ( 12.3 )] . Avoid co-administration of VUMERITY with alcohol [see Clinical Pharmacology ( 12.3 )] . 2.4 Blood Tests to Assess Safety After Initiation of VUMERITY Obtain a complete blood cell count (CBC), including lymphocyte count, 6 months after initiation of VUMERITY and then every 6 to 12 months thereafter, as clinically indicated [see Warnings and Precautions ( 5.4 )].
Excerpted — the section continues on the label. Read the full Dosage and Administration section on DailyMed →
Diroximel Fumarate side effects
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The most common side effects were seen with dimethyl fumarate, which has the same active form as Vumerity.
Common side effects
- Flushing (warmth and redness of the skin)
- Stomach pain
- Diarrhea
- Nausea
- Vomiting
- Itching
- Rash
- Indigestion
When to get medical help
- Call 911 or get emergency help for signs of a serious allergic reaction, such as swelling of the face, lips or throat (angioedema) or trouble breathing (anaphylaxis). Stop the drug and do not restart it.
- Call your doctor right away about any new or worsening symptoms that could signal PML, a rare brain infection. Your doctor may pause the medicine.
- Tell your doctor about signs of a serious infection, including shingles (herpes zoster). Treatment may be held until the infection clears.
- Report signs of liver problems to your doctor.
- Report severe or persistent stomach or bowel symptoms.
- Your doctor will check your lymphocyte (white blood cell) count. Low counts may mean treatment needs to be interrupted.
Get help right away for allergic reactions such as facial swelling or trouble breathing. Call your doctor about signs of infection, liver problems or new neurologic symptoms.
Diroximel Fumarate warnings and precautions
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- Anaphylaxis and angioedema: severe allergic reactions. Stop the drug and do not restart it.
- PML: a rare brain infection. The drug is held at the first sign.
- Serious infections: including shingles. Treatment may be paused until the infection clears.
- Lymphopenia: low lymphocyte counts. A blood count is checked before treatment, at 6 months and every 6 to 12 months after.
- Liver injury, flushing and serious stomach or bowel reactions can also occur.
Diroximel Fumarate interactions
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Few interactions are named, but they matter.
- Dimethyl fumarate: do not combine, because it breaks down to the same active form.
- Alcohol: avoid it with Vumerity.
- High-fat, high-calorie meals: avoid them, because food changes how the drug is absorbed.
- Non-enteric coated aspirin: may reduce flushing when taken beforehand, if your prescriber agrees.
Interactions listed in the FDA-approved label
From the Diroximel Fumarate prescribing information (“Drug Interactions”): what the manufacturer studied or reported to the FDA.
- Dimethyl fumarate: VUMERITY is contraindicated in patients currently taking dimethyl fumarate, which is also metabolized to monomethyl fumarate. VUMERITY may be initiated the day following discontinuation of dimethyl fumarate.
Read the label’s full interactions text
7 DRUG INTERACTIONS 7.1 Concomitant Dimethyl Fumarate VUMERITY is contraindicated in patients currently taking dimethyl fumarate, which is also metabolized to monomethyl fumarate. VUMERITY may be initiated the day following discontinuation of dimethyl fumarate [see Contraindications ( 4 )] .
Not a complete list. The label covers the interactions the manufacturer studied or reported, and our own interaction database does not cover every medicine either. Bring your full medication list, including vitamins and herbal products, to your pharmacist.
Before taking Diroximel Fumarate
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- Do not use it if you are allergic to diroximel fumarate, dimethyl fumarate or any ingredient.
- Baseline blood count and liver tests are needed before starting.
- Not recommended with moderate or severe kidney impairment.
- Pregnancy: animal studies showed harm and human data are not adequate. Talk with your doctor and consider the pregnancy registry.
- Breastfeeding: there are no data on the effects on the infant or milk.
- Children: safety and effectiveness have not been established.
- Adults 65 and older: not enough data to know if response differs.
What Diroximel Fumarate does in the body
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At twice the maximum recommended dose, Vumerity did not prolong the QTc interval (a heart rhythm measurement) to any clinically relevant extent.
How your body processes Diroximel Fumarate
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Your body quickly converts diroximel fumarate into its active form, MMF, and the parent drug is not measurable in blood. MMF peaks in about 2.5 to 3 hours. A high-fat meal lowers the peak and delays it but does not change the total amount absorbed.
MMF is broken down by normal body metabolism, not liver CYP enzymes, and is mostly exhaled as carbon dioxide. Its half-life is about 1 hour, and it does not build up. An inactive byproduct, HES, is cleared mainly in urine, which is why moderate or severe kidney impairment is a concern.
How to store Diroximel Fumarate
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Store at 20°C to 25°C (68°F to 77°F); excursions permitted to 15°C to 30°C (59°F to 86°F).
Written from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
Supplements & herbs that interact with Diroximel Fumarate
106 supplements and herbal products have documented interactions with Diroximel Fumarate in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.
- Major · 4
- Moderate · 92
- Minor · 10
Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.
Diroximel Fumarate: pharmacist answers to common questions
Quick, plain-English answers to the questions patients ask most about Diroximel Fumarate — the kind of thing our pharmacy team would talk through with you at the counter.
What is this medicine for?
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How do I take it?
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Can I take it with food or alcohol?
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What side effects should I expect?
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When should I call my doctor or get emergency help?
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Why do I need blood tests?
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Is Diroximel Fumarate available over the counter?
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When was Diroximel Fumarate first available?
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Answers drafted from the FDA-approved label with AI and reviewed by our pharmacy team. How we use AI →
More about Diroximel Fumarate on HelloPharmacist
Diroximel Fumarate forms and strengths (how it comes)
Diroximel Fumarate is available in 2 forms. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Need a version that does not list lactose, a gluten source, a dye or gelatin? Inactive ingredients differ by manufacturer: see Diroximel Fumarate inactive ingredients by manufacturer.
Capsule
How this form is used
- Vumerity is used to treat relapsing forms of multiple sclerosis in adults.
- Vumerity capsules are swallowed whole and intact, twice a day.
- Do not crush or chew Vumerity capsules or sprinkle the contents on food.
- If taking Vumerity with food, avoid high-fat, high-calorie meals or snacks.
- Avoid alcohol while taking Vumerity.
Delayed-release capsule
Diroximel Fumarate on the U.S. market: products, makers and brands
How Diroximel Fumarate appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
1 company lists 1 Diroximel Fumarate product record with the FDA, mostly as capsule, delayed-release capsule; the earliest marketing or approval year on record is 2018. Brand names on the directory include Vumerity; the rest are generics.
FDA-listed product records by dose form (tablet variants merged) — FDA National Drug Code Directory. Record counts are not sales or prescription volume.
Also listed with the FDA, not a patient dose form: Powder (5) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.
How widely Diroximel Fumarate is used (Medicaid data)
A general measure of how commonly Diroximel Fumarate is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.
Think of this as a proxy for how widely Diroximel Fumarate is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.
How commonly is Diroximel Fumarate prescribed? Of the 1,601 medications we measure, Diroximel Fumarate ranks #995 by Medicaid prescriptions — more than 38% of them.
Utilization by Diroximel Fumarate product
Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.
diroximel fumarate 231 MG Delayed Release Oral Capsule
Summed across the 1 of 7 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 2261788
Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.
Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Diroximel Fumarate, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 1 of 7 listed Diroximel Fumarate NDCs with Medicaid activity.
Compare Diroximel Fumarate products
A representative set of FDA-listed product records for Diroximel Fumarate — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Capsule | ||||
| 231 mg | Oral | Biogen Inc. | NDA | View NDC → |
Showing 1 of 1 products — FDA National Drug Code Directory. See every product, package size and price: browse all 1 Diroximel Fumarate NDCs →
Diroximel Fumarate side effects reported to the FDA (FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Diroximel Fumarate — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Diroximel Fumarate in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
Diroximel Fumarate FDA approval history
How Diroximel Fumarate went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
Diroximel Fumarate recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
The FDA’s enforcement reports list no Diroximel Fumarate recalls since July 2021.
✅No Diroximel Fumarate recalls on record since July 2021Source: FDA enforcement (recall) reports, via openFDA; our copy was last updated Sep 24, 2026.
Diroximel Fumarate supply and shortage status
Whether Diroximel Fumarate is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
Diroximel Fumarate brand names
Diroximel Fumarate is sold under one brand name in the FDA directory — Vumerity. A brand and its generic contain the same active ingredient; the brand name belongs to one company's product.
Who makes Diroximel Fumarate: manufacturers and labelers
One company lists Diroximel Fumarate products with the FDA. By number of product records, the largest are Biogen Inc.. Labelers include manufacturers and repackagers; the product in your bottle depends on which one your pharmacy stocks.
Diroximel Fumarate drug class (RxNorm)
Diroximel Fumarate belongs to the Other immunosuppressants class.
Classified by RxNorm RxClass — the U.S. National Library of Medicine's standardized drug-classification service (Established Pharmacologic Class from the FDA, the ATC drug family from the WHO, and mechanism of action). Reference only, not medical advice.
Sources for this Diroximel Fumarate page
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How this page is built
HelloPharmacist combines public FDA and NLM records and does not author the underlying clinical facts. The plain-language sections are written with AI from the FDA-approved label text and reviewed by our pharmacy team before publication. Biogen Inc. is the representative DailyMed label linked for verification and dates. This is general education, not medical advice: always talk to your doctor or pharmacist about your own medicines. How we build and review drug pages →