Medications That Can Cause Weight Gain
If you gained weight after starting a new prescription, it might not be in your head. Here are the common culprits, and how to raise it with your prescriber.
The short version
- Many common medications can cause weight gain, some by several pounds or more.
- Never stop or change a prescription without talking to your prescriber first, as that can be dangerous.
- There's often a weight-neutral alternative. Ask about it.
- Medication isn't a personal failing, and for many people, treating the condition comes first.
Common culprits
These are examples, not a complete list. Effects vary widely, and many people on these medications don't gain any weight. Ask your clinician or pharmacist about your own prescriptions.
| Used for | Can cause gain | May be more weight-neutral (ask first) |
|---|---|---|
| Depression | Mirtazapine, paroxetine, amitriptyline | Bupropion or fluoxetine |
| Psychosis, bipolar disorder | Olanzapine, clozapine, quetiapine, risperidone, lithium, valproate | Aripiprazole, ziprasidone, lurasidone |
| Seizures, nerve pain, migraines | Gabapentin, pregabalin, valproate, carbamazepine | Topiramate, lamotrigine, zonisamide |
| Diabetes | Insulin, sulfonylureas, pioglitazone | Metformin, GLP-1 drugs, SGLT2 inhibitors |
| High blood pressure, heart | Older beta blockers such as metoprolol and atenolol | ACE inhibitors, ARBs, calcium channel blockers |
| Inflammation | Prednisone and other steroids | Depends on the condition. Sometimes inhaled or shorter courses |
| Allergies | Possibly older antihistamines, though the evidence is limited | Ask your pharmacist |
| Hormones | Some hormonal contraception, such as the depot shot | Depends on the person |
How they cause it
Depending on the drug, medications can increase appetite, cause fluid retention, make you tired so you move less, or change how your body handles sugar and stores fat. Some effects appear in the first few months, and others are slow and easy to miss.
How to tell if it's your medication
- Did the weight gain start within a few months of a new drug or dose?
- Have your appetite, cravings or energy changed?
- Are your eating and activity habits about the same?
- Are you retaining fluid?
Keep a simple timeline of your medications and weight, and bring it with you. Patient apps and pharmacy records can help.
What to say
Options your prescriber might consider
- Switching to a different drug in the same or a similar class
- Lowering your dose, if that's appropriate
- Changing the timing or formulation
- Adding a treatment that offsets weight gain, in some cases
- Using a shorter course, such as with steroids
- Reviewing whether you still need the medication at all
Sometimes the medication that's working is the right one to stay on, even with some weight gain. Stable mental health, for example, may be worth a lot more than a few pounds. You and your clinician can weigh that up together.
Things you can still do
Even on a medication that affects your weight, people can often limit or reverse the gain:
- Keep meals structured and plan your snacks if your appetite is up.
- Prioritize protein and fiber.
- Keep moving, even when you're tired. See the walking plan.
- Weigh yourself regularly, so you catch weight changes early.
Sources
This guide is general information, not medical advice. Please check with a clinician before making big changes, especially if you have a health condition, take medication, or are pregnant. Read the full disclaimer.
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