Dimethyl fumarate

Dimethyl fumarate is a tablet treatment for relapsing multiple sclerosis. A version called Skilarence is used for psoriasis.

Type of medicine

Disease-modifying therapy for multiple sclerosis

Also known as

Tecfidera, Skilarence

Comes as

gastro-resistant capsules, tablets

How you get it

Started by a specialist, then sometimes prescribed by a GP

What it is used for

Relapsing remitting multiple sclerosis (Tecfidera)
Moderate to severe plaque psoriasis (Skilarence)

Read our guides:

Off-label uses

Doctors sometimes prescribe a medicine for a condition it is not officially licensed for. This is called off-label use. It is legal and common when there is good evidence it helps, and your doctor should explain why they are suggesting it.

Dimethyl fumarate is not commonly used off-label.

How it works

Dimethyl fumarate is thought to calm the immune system and protect nerve cells from damage. In MS, this reduces the number of relapses. In psoriasis, it reduces inflammation in the skin.

Side effects

Like all medicines, Dimethyl fumarate can cause side effects, although not everyone gets them. Many are mild and ease after the first few weeks.

Common side effects

flushing (red or hot itchy skin)
diarrhoea
stomach pain
feeling sick
low white blood cell count

Tell your doctor or pharmacist if these bother you or do not go away.

Serious side effects

These are rare. Call 111 or contact your doctor straight away if you get:

signs of infection, such as a high temperature
new or worsening weakness, clumsiness, changes in vision, thinking or memory, which can rarely be signs of a brain infection called PML
yellowing of the skin or eyes

Call 999 if you have signs of a serious allergic reaction, such as swelling of your lips, mouth, throat or tongue, or trouble breathing.

You can report any side effect to the Yellow Card scheme, run by the medicines regulator.

Stopping and withdrawal

Important safety information

You need regular blood tests to check your white blood cells.
Taking it with food can reduce flushing and stomach side effects.

Questions about your medicine?

A pharmacist can answer questions about your medicines for free, without an appointment. You can also ask your GP for a medication review. Check if you can get free prescriptions.