Dimethyl: uses, dosing, side effects & brands
Dimethyl is a medicine sold in the U.S. under 2 brand and generic names. Below: what the FDA label says, every product that contains it, what the pills look like, and its recall record.
Key facts
- Available as
- Capsule · Capsule, delayed release · Kit
- Sold as
- 2 products — Dimethyl Fumarate and Tecfidera
- Prescription?
- Prescription only
- Generic available?
- Yes
- What the pharmacy pays
- about $16 for a 30-count supply — not your price
How dimethyl is dosed
From the FDA label for Dimethyl Fumarate (application ANDA210440). Other dimethyl products — different forms, different strengths — are dosed differently. Follow the label for the one you were prescribed.
Starting dose: 120 mg twice a day, orally, for 7 days ( 2.1 ) Maintenance dose after 7 days: 240 mg twice a day, orally ( 2.1 ) Swallow dimethyl fumarate delayed-release capsules whole and intact. Do not crush, chew, or sprinkle capsule contents on food ( 2.1 ) Take dimethyl fumarate delayed-release capsules with or without food ( 2.1 ) 2.1 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 [see Clinical Pharmacology ( 12.3 )]. Dimethyl fumarate delayed-release capsules should be swallowed whole and intact. Dimethyl fumarate delayed-release capsules should not be…
Dimethyl side effects
The following important adverse reactions are described elsewhere in labeling: Anaphylaxis and Angioedema [see Warnings and Precautions ( 5.1 )] Progressive multifocal leukoencephalopathy [see Warnings and Precautions ( 5.2 )] Herpes Zoster and Other Serious Opportunistic Infections [see Warnings and Precautions ( 5.3 )] Lymphopenia [see Warnings and Precautions ( 5.4 )] Liver Injury [see Warnings and Precautions ( 5.5 )] Flushing [see Warnings and Precautions ( 5.6 )] Serious Gastrointestinal Reactions [see Warnings and Precautions ( 5.7 )] Most common adverse reactions (incidence ≥10% and ≥2% placebo) were flushing, abdominal pain, diarrhea, and nausea. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Ascend Laboratories, LLC at 1-877-272-7901 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 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 2,513 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 1,169 patients have received more than…
Who shouldn’t take dimethyl
Dimethyl fumarate delayed-release capsules is 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 [see Warnings and Precautions ( 5.1 )]. Known hypersensitivity to dimethyl fumarate or any of the excipients of dimethyl fumarate delayed-release capsules. ( 4 )
Every dimethyl product we track (2)
Same active ingredient — different manufacturer, form, price and FDA recall record. That last one is what our independent score measures.
| # | Drug | Rating | Type | Form | Generic? | Pharmacy pays | |
|---|---|---|---|---|---|---|---|
| 1 | Not yet rated | Prescription | Capsule | Generic | $16 | View → | |
| 2 | Not yet rated | Prescription | Capsule | Generic | $16 | View → |
What dimethyl pills look like
Imprint codes, colour and shape from the FDA’s labelling data. Match the imprint on your pill — or search any imprint.
| Imprint | Strength | Colour | Shape | Maker |
|---|---|---|---|---|
| DMT240 | 240 mg | green | capsule | — |
| DMT120 | 120 mg | white | capsule | — |
| T127;120mg | 120 mg | green, white | capsule | — |
| T128;240mg | 240 mg | green, green | capsule | — |
| T127;120mg | 120 mg | green, white | capsule | — |
| T128;240mg | 240 mg | green, green | capsule | — |
| H;D15 | 240 mg | white | capsule | — |
| 120 | 120 mg | green | capsule | — |
| 240 | 240 mg | green | capsule | — |
Can you crush or split dimethyl?
At least one dimethylproduct is labelled to be swallowed whole — crushing an extended-release tablet releases the whole day’s dose at once. Which applies depends on the form you were given.
What each dimethyl label says about crushing, splitting and chewingWhat people report to the FDA about dimethyl
The FDA Adverse Event Reporting System (FAERS) collects reports from patients and clinicians. It holds 3,464 reports naming dimethyl, and the FDA flagged 59% of those reports as serious. The effects reported most often — leaving out reports about overdose, misuse or the condition being treated, which dominate the raw list for common medicines:
- flushing328 reports
- fall223 reports
- multiple sclerosis relapse219 reports
- fatigue168 reports
- diarrhoea166 reports
- nausea150 reports
- multiple sclerosis148 reports
- gait disturbance123 reports
Read these as a signal, not a rate. A report does not mean dimethyl caused the effect — anyone can file one, and many describe people taking several medicines for several conditions. Crucially there is no denominator: FAERS does not record how many people took the drug, so these counts cannot be turned into “X% of patients” — a bigger number often just means a more widely used or more talked-about drug. Duplicates exist, and publicity drives reporting. For what is actually established, read the FDA label section above.
Source: openFDA drug/event (FAERS), retrieved July 25, 2026.
Related calculators
Frequently asked questions
What is dimethyl?
Dimethyl Fumarate is a medication supplied as a capsule, capsule, delayed release and kit.
Can you take dimethyl with other medicines?
It depends on the medicine. We check it against the FDA labels rather than guessing: our interaction checker searches each drug's own label for the other and quotes what it says, naming the section it came from. Run dimethyl against whatever else you take — and remember that a label not naming a drug is not the same as that combination being safe.
What brand names is dimethyl sold under?
We track 2 dimethyl-containing products in the U.S.: Dimethyl Fumarate and Tecfidera. They are the same active ingredient; they differ in form, manufacturer, price and FDA recall record.
What forms does dimethyl come in?
Across the brands we track, dimethyl is currently marketed as capsule, capsule, delayed release and kit, per the FDA's National Drug Code Directory. Each form is dosed differently — follow the label for the exact product you were prescribed.
Is there a generic dimethyl?
Yes. Our catalog lists 1 generic dimethyl product alongside the brand versions. A generic has the same active ingredient and must meet the FDA's bioequivalence standard; it usually costs less. Ask your pharmacist which one your plan covers.
Cite this page
- APA
- pharmaranks. (2026, July 24). Dimethyl: uses, dosing, side effects & brands. https://pharmaranks.com/drugs/dimethyl
- MLA
- “Dimethyl: uses, dosing, side effects & brands.” pharmaranks, 24 July 2026, https://pharmaranks.com/drugs/dimethyl.
We summarise public FDA and NIH sources — for a clinical claim, cite the primary source we link to as well.
Sources: FDA openFDA drug label, National Drug Code Directory, and Enforcement (recall) database. This page reproduces public FDA data and is not medical advice. Dosing is set by your prescriber.
Read the full FDA label for dimethyl on DailyMed (NIH) ↗.