What is mycophenolate?

Mycophenolate is an immunosuppressant that calms an overactive immune system. We use it for lupus (including lupus that affects the kidneys), inflammatory muscle disease (myositis), mixed connective tissue disease (MCTD), scleroderma, vasculitis, and interstitial lung disease (ILD) — inflammation and scarring in the lungs that can come with autoimmune conditions.

It works by blocking a step that immune cells (lymphocytes) need to multiply. With fewer of these cells being made, the inflammation driving your disease settles down. Mycophenolate is often used as a steroid-sparing medication — one that lets us lower your prednisone over time.

CellCept and Myfortic — the two forms

Mycophenolate comes in two forms, and they are not interchangeable milligram-for-milligram:

CellCept (mycophenolate mofetil) — the original and most common form.
Myfortic (mycophenolate sodium) — a delayed-release (“enteric-coated”) version designed to be gentler on the stomach.

The two are dosed differently: CellCept 1000 mg twice daily is roughly equal to Myfortic 720 mg twice daily. If your pharmacy ever switches you between them, check with us first so the dose stays right.

How to take it

Twice a day, morning and evening. We usually start low and build up to your target dose over a few weeks.
Take it consistently — ideally on an empty stomach (1 hour before or 2 hours after eating), which helps absorption. If nausea is a problem, taking it with a little food is a reasonable trade-off; the key is taking it the same way each day.
Swallow capsules and tablets whole. Don’t crush, chew, or open them.

Important: If someone in your home is pregnant or may become pregnant, they should not handle broken tablets or open capsules — the powder inside can harm a developing baby.

What to expect when starting

Mycophenolate is slow-acting. Most patients notice benefit over 6–12 weeks, sometimes longer. Keep taking it even before you feel a change.

The most common early problem is stomach upset — nausea, cramping, or diarrhea. This is usually dose-related and often improves. If it doesn’t, tell us: splitting the daily amount into smaller, more frequent doses, or switching from CellCept to Myfortic, frequently helps.

Lab monitoring

You will need regular blood work on mycophenolate:

Complete blood count (CBC) — checks your white cells, red cells, and platelets.
Comprehensive metabolic panel (CMP) — checks your liver and kidney function.

We check labs every 4 weeks while we adjust your dose. Once you’ve reached a stable dose, we lock monitoring in at every 3 months for the long term.

This is how we catch the things mycophenolate can do quietly — lower your blood counts or, less often, irritate the liver — before they cause symptoms.

Side effects to watch for

Fever, chills, sore throat, or other signs of infection — mycophenolate can lower your white blood cells and raise infection risk.
Persistent diarrhea, nausea, or stomach cramping that isn’t improving.
Unusual bruising or bleeding — a sign of low platelets.
Unusual tiredness or shortness of breath — possible anemia.
A new or changing skin spot — see sun protection below.
New weakness, confusion, or vision or speech changes — rare, but tell us promptly.

Pregnancy — the most important warning

Boxed warning: Mycophenolate causes miscarriage and serious birth defects if taken during pregnancy. Do not take it if you are pregnant or trying to become pregnant.

Because of this risk, mycophenolate is prescribed under a federal safety program (a REMS), and there are firm rules for anyone who could become pregnant:

A pregnancy test before you start, and a second one 8–10 days later.
Two reliable forms of birth control used together throughout treatment and for 6 weeks after your last dose.
Mycophenolate can make hormonal birth control (the pill, patch, or ring) less effective, so a barrier method such as condoms must be added — or use a highly effective option like an IUD or implant.

If you are a man whose partner could become pregnant, use condoms during treatment and for 90 days after stopping.

Important: If you think you might be pregnant, do not stop the medication on your own — call us the same day so we can guide you safely.

Things to avoid

Live vaccines — such as the live shingles vaccine (Zostavax) or the live nasal flu spray. Inactivated vaccines (flu shot, COVID, Shingrix) are safe and encouraged.
Antacids, and some acid-reducers and cholesterol binders — magnesium/aluminum antacids and cholestyramine reduce how much mycophenolate you absorb. Separate antacids from your dose by a couple of hours, and tell us what over-the-counter products you take.
Excess sun. Mycophenolate raises the long-term risk of skin cancer. Use sunscreen, wear a hat, and get any new or changing skin spot checked.
Alcohol — occasional, moderate use is generally fine.

Frequently asked questions

Why does the stomach upset happen, and will it last? It comes from the medication’s effect on the fast-turnover cells lining your gut. It’s usually worst early and often eases as your body adjusts. Splitting the dose or switching to Myfortic helps many people — let us know rather than stopping on your own.

Can I get vaccinated? Yes — inactivated vaccines (flu, COVID, Shingrix) are recommended. Avoid live vaccines, and talk to us before any new vaccination.

What if I miss a dose? Take it when you remember, unless it’s nearly time for the next dose — then skip the missed one. Never double up.

How long will I take it? Often for years, as long as it’s controlling your disease and your labs stay stable. We’ll revisit this as part of your ongoing care.

This handout is provided for educational purposes and does not replace individualized medical advice. Always follow the specific instructions given by your rheumatologist.

Mycophenolate (CellCept, Myfortic): What You Need to Know