Leflunomide is a prescription drug most often used to treat rheumatoid arthritis and psoriatic arthritis. It can slow joint damage and reduce inflammation, but it also has important risks — especially for your liver and for pregnancy. If you or someone close to you has been prescribed leflunomide, these plain facts will help you use it more safely.
Leflunomide lowers the activity of certain immune cells by blocking an enzyme called DHODH. That reduces the autoimmune attack on joints, which eases pain and swelling. Doctors commonly start with a short loading dose (often 100 mg daily for three days) and then move to a maintenance dose, usually 10–20 mg once daily. Follow your prescriber’s exact instructions — don’t change dose or stop suddenly without medical advice.
It’s a long-acting medicine. Without special treatment it can stay in your body for months because of enterohepatic circulation. If you need the drug out of your system quickly (for example, if you want to get pregnant), doctors use a washout with cholestyramine to speed elimination.
Common side effects include diarrhea, hair thinning, and nausea. More serious problems are liver damage, lowered blood counts, high blood pressure, and increased risk of infections. Before you start, your doctor should check liver enzymes, a full blood count, and pregnancy status if relevant. Regular blood tests are needed while you’re on treatment so problems can be spotted early.
Leflunomide can cause severe birth defects. Women must avoid getting pregnant while taking it. If you plan pregnancy, talk to your doctor about a washout procedure — typically cholestyramine 8 g three times daily for 11 days — and confirm drug levels are low before trying to conceive. Men should also discuss family planning with their prescriber.
Drug interactions matter. Combining leflunomide with other drugs that affect the liver (for example, methotrexate or heavy alcohol use) raises risk. Live vaccines aren’t recommended while your immune system is suppressed. Always tell your prescriber about every medicine and supplement you take.
Practical tips: always get a written plan for blood tests, avoid alcohol while your liver is being monitored, report fever or unexplained bruising right away, and carry a list of your meds when you see any clinician. If you’re worried about pregnancy or side effects, ask about the washout procedure and how long you should wait before trying to conceive.
Buying leflunomide? It’s prescription-only. Use licensed pharmacies and never skip verification steps when ordering online. If something about a pharmacy feels off — no valid contact info, unusually low prices, or no prescription requirement — don’t risk it. Talk to your doctor or a trusted pharmacist for safe sourcing and clear next steps.
If you want more detail on dosing, monitoring schedules, or the washout process, bring questions to your prescriber — they’ll tailor advice to your health and goals.
