It’s natural to worry about side effects when starting any new lupus treatment. For example, one MyLupusTeam member expressed concern about weight gain after their doctor switched them from azathioprine (Imuran) to mycophenolate mofetil (CellCept): “The azathioprine has helped me lose some of the weight prednisone has packed on and made my joints feel better overall. I was hoping mycophenolate would continue the luck.”

Putting on unwanted pounds from medication can have a big impact on your physical and mental health. Although everyone responds differently to medications, it can be helpful to know what to expect before starting a new treatment.

Mycophenolate for Lupus

Mycophenolate — sold as either mycophenolate mofetil or mycophenolate acid (Myfortic) — can be used to treat and prevent lupus flares in people with systemic lupus erythematosus (SLE). The drug works by weakening the immune system to keep it from attacking healthy tissue throughout your body.

You might be prescribed mycophenolate if you have severe lupus symptoms that cause problems with major organs like your kidneys, brain, heart, or lungs. Mycophenolate is a common treatment for people with kidney problems caused by lupus or lupus nephritis.

Mycophenolate is known as a steroid-sparing treatment, which means it allows you to decrease your dose of corticosteroids (such as prednisone). A lower dose of prednisone can reduce the risk of side effects that can sometimes be serious, including:

• Weight gain
• Mood changes
• Osteoporosis (thinning bones)
• Eye problems
• Muscle weakness
• Heart disease
• Stomach problems

What Are the Most Common Side Effects of Mycophenolate?

Although taking mycophenolate can decrease steroid-related side effects, it does have the risk of unwanted effects of its own, which vary from person to person. Some people don’t develop any mycophenolate-related problems, while others may have side effects so severe that they need to stop taking the medication. However, mycophenolate is generally well-tolerated.

The most common mycophenolate side effects are diarrhea, pain, vomiting, high blood pressure, and swelling of the legs, feet, and ankles.

Other possible side effects include:

• Unusual weight gain or loss
• Trouble falling asleep or staying asleep
• Headache
• Muscle or joint pain
• Tremors (uncontrolled shaking)
• Skin sensations of tingling or burning

More serious side effects of mycophenolate include:

• Chest pain
• Difficulty breathing
• Rash
• Itching
• Fainting, dizziness, or pale skin
• Increased risk of cancers such as lymphoma and skin cancer
• Severe stomach pain and intestinal bleeding (characterized by vomiting blood that looks like coffee grounds, as well as bloody or black, tarry stools)
• Fever or muscle pain not caused by infection
• Risk of serious infections

Mycophenolate and Weight Changes

Weight changes are possible side effects of mycophenolate. In clinical trials, some participants taking mycophenolate mofetil experienced weight loss or weight gain. The exact number of people who experienced these changes is not well defined. The reported rate ranges from 3 percent to 20 percent.

Several MyLupusTeam members reported that mycophenolate didn’t cause weight gain. One member said, “I’ve been on mycophenolate since May 2015. It has not affected my weight.”

Another commented, “I’ve been on mycophenolate for years and didn’t gain weight.”

Mycophenolate and Weight Gain

It’s not clear how mycophenolate may cause weight gain. Other side effects of the medication may lead to weight gain. One of these side effects is swelling in the hands, arms, lower legs, ankles, or feet — also known as peripheral edema. In clinical trials, between 27 percent and 64 percent of people taking mycophenolate mofetil experienced this side effect.

Symptoms of peripheral edema include:

• Puffiness or swelling just below the skin
• Shiny, stretched-looking skin
• Pitting edema (skin that holds a dimple after being pressed)
• Heavy feeling in legs or arms

If you notice any abnormal swelling, it’s important to contact a healthcare provider right away. Swelling can also be a sign of other serious medical conditions, such as heart, kidney, or liver disease, or damage to your veins. You should contact your healthcare provider if you experience any type of weight gain while taking mycophenolate.

Mycophenolate and Weight Loss

Weight loss may also be attributed to other side effects of mycophenolate. Stomach-related side effects like nausea and vomiting may cause weight loss. Unexplained weight loss could also be a sign of cancer. A higher risk of cancer is a very rare side effect of mycophenolate. Talk to your doctor if you lose a significant amount of weight without trying.

Other Causes of Weight Gain With Lupus

If you experience weight changes while taking mycophenolate with lupus, they may be caused by something else. In 2022, between 28 percent and 50 percent of people with SLE worldwide had obesity, as compared to around 13 percent of the general population.

People with lupus may be more likely to gain weight and have a higher body weight because of certain factors, such as:

• Steroid use — Taking these medications can lead to increased appetite and weight gain.
• Low physical activity — Lupus symptoms like fatigue, stiffness, and pain can make it hard to stay active.
• Thyroid disease — Hypothyroidism (the thyroid gland doesn’t make enough thyroid hormone) is more common in people with lupus and is associated with weight gain.
• Low levels of vitamin D — It’s common for people with lupus to lack vitamin D, a deficiency that is associated with high body weight.

Managing Your Weight During Lupus Treatment

Talk with your healthcare provider if you’re concerned about weight changes with lupus. It’s important to seek medical advice before making any major changes to your diet or exercise regimen.

Choose Healthy Foods

There isn’t one specific diet for lupus, but focusing on nutritious foods can help you manage your weight, ease lupus symptoms, and improve your overall health. Strive for a balanced diet that includes:

• Plenty of fruits and vegetables
• Lean protein, including chicken, fish, egg whites, beans, peas, lentils, and tofu
• Whole grains like whole-wheat bread and brown rice
• Healthy fats like olive oil and avocados

Stay as Active as Your Lupus Allows

Lupus symptoms can make it difficult to engage in regular exercise, but — surprising as it may seem — physical activity can actually improve issues like fatigue and joint pain. It can also help manage weight gain.

It can be tough to get started, but it helps to choose an activity that fits well with both your routine and your physical abilities. Anything that gets you moving can help, whether that means taking a walk, going for a bike ride or a swim, or practicing a low-impact routine such as yoga.

Be Mindful of Your Medications

If you feel that your medication is causing weight gain, ask your rheumatologist about switching to a different type. Lupus treatment options include antimalarial drugs like hydroxychloroquine (Plaquenil), immunosuppressants like methotrexate, and biologics like belimumab (Benlysta).

It might take some trial and error, but you and your healthcare provider can find the right regimen to manage your lupus and sidestep side effects as much as possible.

Join the Conversation

On MyLupusTeam, people share their experiences with lupus, get advice, and find support from others who understand.

Have you taken mycophenolate for lupus? Have any of your lupus treatments caused weight gain? Let others know in the comments below.