Back to main page


This medication can help you lose weight by reducing appetite and cravings.

Get Started

Branded names

Zonegran®, ZonisadeTM

Conditions FDA-approved to treat


Benefits for weight loss

Reduce appetite

The results are in...

  • How it works

    While Zonisamide is FDA-approved for the treatment of partial seizures in adults with epilepsy, it is also commonly used by leading specialist obesity clinicians and weight clinics off-label to help promote weight loss by reducing appetite and cravings.

  • Form and dosing

    Zonisamide typically comes in a capsule form with dosages starting at 25 mg. Dosing instructions vary according to weight, tolerability and other factors and should be discussed with your healthcare provider.

  • Common side effects
    • dizziness and lightheadedness
    • fatigue and drowsiness
    • language and speech difficulty
    • metallic taste
    • nausea

What are doctors saying?

“Zonisamide is an effective off-label medication for appetite and craving control. It can be used alone or in combination with other medications to help target multiple mechanisms of weight loss.”

— Dr. Rekha Kumar, Chief Medical Officer at Found

“The antiepileptic drug zonisamide moderately enhances the weight loss achieved with diet and lifestyle counseling, but is associated with a high incidence of adverse events.”

— Psychiatry Online

When used in combination with other medication

Bupropion + Zonisamide

“Bupropion and Zonisamide is an off-label combination of medications that can reduce overall hunger, increase fullness, and help with overeating and cravings.”

— Dr. Rekha Kumar, Chief Medical Officer at Found

Medical Disclaimers

Zonisamide is only FDA-approved to treat seizures. Prescribing medications are up to a medical provider’s discretion and may not be appropriate for everyone.

More science-based weight care
How prescription pills can help with sustainable weight loss
Read More
How you’ll lose weight when you’re on weight loss meds
Read More
Understanding off-label weight loss medication — and how it could work for you
Read More
Do I need medication to maintain weight loss?
Read More

Zonisamide warnings


DO NOT take zonisamide if you have an allergy to sulfa drugs. A potentially fatal reaction can occur including a life threatening skin rash or a blood cell condition.

Before using zonisamide, tell your healthcare provider about your medical history, especially if you have:

  • kidney disease
  • liver disease
  • long-term diarrhea
  • lung or breathing problems
  • metabolic acidosis or diabetic
  • ketoacidosis
  • high ketone levels in your blood or urine
  • you use insulin or other diabetes medications
  • history of psychiatric disorders or suicidal thoughts

Talk to your healthcare provider if you are planning to become pregnant or if pregnant or breastfeeding. Avoid alcohol and stay well hydrated while taking this medication. Do not drive, operate heavy machinery or perform any hazardous task until the effects of this medication are known to you. Tell your healthcare provider right away if you experience eye pain, changes in vision, eye swelling or redness, yellowing of the eyes, confusion, difficulty concentrating, suicidal thoughts, memory problems, trouble thinking clearly, agitation, irritability, speech problems, decreased sweating, sudden flank pain, painful urination, dark urine, increased fatigue, skin rash, faintness, easy bruising, irregular or fast heartbeat, bone pain, rapid breathing, dizziness, or stomach pain that is severe or that lasts more than a few days.

Side effects information

Many people experience no side effects while taking zonisamide. The most common side effects of zonisamide include:

  • dizziness and lightheadedness
  • fatigue and drowsiness
  • language and speech difficulty
  • metallic taste
  • nausea

Other possible side effects include:

  • trouble sleeping
  • lack of coordination
  • loss of appetite and weight loss
  • diarrhea
  • double vision
  • mood changes such as depression or irritability
  • difficulty concentrating

These symptoms may subside after your body adjusts to the medication.

Drug interactions

As with other medications, zonisamide can interact with certain medications, including carbonic anhydrase inhibitors (such as acetazolamide), orlistat (if using zonisamide for a seizure disorder), phenobarbital, primidone, rifamycins, glucocorticoids, and St. John's wort.

Please consult the pharmaceutical packaging for a full list of side effects, warnings, interactions and additional information. Do not stop taking this medication without consulting your healthcare provider because some conditions may become worse when the drug is suddenly stopped.

To report suspected adverse reactions to topiramate contact the FDA at 1-800-FDA-1088 or

In case of emergencies, please call 911 or go to the nearest emergency room.