Dimethyl Fumarate: What You Need to Know

Dimethyl fumarate is a prescription medicine used mainly for relapsing multiple sclerosis (branded as Tecfidera) and, in some countries, for psoriasis. It helps reduce immune-driven inflammation that attacks nerve tissue or skin. If you or a loved one were prescribed dimethyl fumarate, this page gives useful, plain-language facts about how it works, common side effects, monitoring, and smart steps for buying it safely online.

How it works and how to take it

Dimethyl fumarate works by calming parts of the immune system. That lowers the number of relapses in MS and can reduce skin lesions in psoriasis. It usually comes as oral capsules or delayed‑release capsules taken twice a day. The dose often starts low and increases over a few weeks to reduce side effects. Follow your doctor’s exact instructions — do not change dose or stop suddenly without medical advice.

Common side effects and what to watch for

The most common problems are flushing (warmth, redness) and stomach upset — nausea, diarrhea, or abdominal pain. These often appear early and may ease with time. Taking your dose with food usually helps reduce both flushing and stomach symptoms. Some people find a low‑dose aspirin before the dose cuts flushing, but check with your provider first.

A serious risk is a drop in white blood cells (lymphopenia), which raises infection risk. Your doctor should check blood counts before starting treatment and at regular intervals while you’re on it. If you develop fever, persistent cough, unexplained bruising, severe abdominal pain, or new neurological symptoms, contact your healthcare provider right away.

Dimethyl fumarate can affect liver tests in some people. Periodic liver monitoring is common, especially early in treatment. If you’re pregnant, planning pregnancy, or breastfeeding, talk to your doctor — many prescribers avoid it unless benefits clearly outweigh risks.

Safe use and buying tips

Dimethyl fumarate is prescription‑only. Don’t buy from sites that sell it without a prescription. If you shop online, pick licensed pharmacies that require a valid prescription and show clear contact details, licensing information, and customer service. Look for third‑party seals, read recent reviews, and avoid prices that look too good to be true. Counterfeit or improperly stored meds can be ineffective or dangerous.

Keep a record of blood tests and side effects, bring them to appointments, and ask your provider about vaccinations before starting treatment — live vaccines may not be recommended while your immune system is altered. If you’re switching from another immune treatment, your doctor will advise on timing to lower infection or rebound risks.

Have questions about side effects or safe buying options? Talk with your neurologist or pharmacist. They can help you balance treatment benefits and risks and point you to trusted pharmacies if you need a refill.