Topiramate (Topamax) for weight loss: Does it work?

Key Points

• Topiramate (Topamax) is an anticonvulsant used to treat epilepsy and migraines
• Topamax is not FDA-approved for weight loss, but weight loss is a side effect
• Topiramate is part of Qsymia, a combination weight loss drug of phentermine and topiramate
• Studies show that topiramate results in a 5-7% weight loss over 6 months

Topamax (topiramate) was designed to calm overactive electrical signals in the brain. It was originally developed to treat epilepsy and prevent migraines.

Weight loss was never part of the plan.

Yet during clinical trials, researchers kept noticing something: some people taking Topamax were losing weight.

That finding changed how topiramate, sold under the brand name Topamax, is used today. Some doctors prescribe it off-label (even though it’s not FDA-approved for weight loss). It is also one of two main ingredients in Qsymia, an FDA-approved combination weight loss drug.

But how does topiramate actually work, what are the risks, and how do its weight loss results compare with Wegovy, Zepbound, and other new GLP-1 weight loss medications? This guide gives you all you need to know.

What is topiramate (Topamax)?

Topiramate is an oral anticonvulsant medication that works on the brain and nervous system. It is designed to calm overactive electrical signals in the brain.

It is approved by the FDA to treat:

• Certain types of seizures
• Preventing migraines

Topiramate is the main ingredient in the medication, and Topamax is one of its brand names.

Is topiramate (Topamax) approved for weight loss?

Topiramate is not approved by the FDA for weight loss.

However, during clinical trials, researchers noticed that people taking topiramate lost some weight. Some people may find that their appetite naturally decreases, while others may experience fewer food cravings.

This is why some doctors prescribe topiramate off-label for weight loss, even though the FDA never approved it for that purpose.

But there is an FDA-approved weight loss option that contains topiramate.

Qsymia is a weight loss drug that combines topiramate with phentermine.

How effective is topiramate (topamax) for weight loss? How fast does it work?

Topiramate (Topamax) weight loss results

Clinical trials report an average weight loss of 5-7% over about 6 months. This means that someone starting at 200 lbs may lose about 10-14 pounds. Please note that individual outcomes vary.

Qsymia weight loss results

Studies show that Qsymia can produce significant weight loss when combined with diet and exercise. People taking lower doses of Qsymia lost an average of ~8% of their body weight over a year, and those on higher doses lost as much as 10%.

How does topiramate (Topamax) help with weight loss?

Much of how topiramate influences weight comes down to the brain. Several mechanisms appear to work together, though researchers are still mapping out the details.

1. Appetite suppression and feeling full faster (satiety)

The main weight loss effect of Topamax may be appetite suppression. Based on studies, people taking topiramate felt satisfied faster with less food.

1. Fewer cravings

The brain's reward system responds differently to food when taking topiramate. Typically, eating triggers pleasure signals, just like every other action needed for our survival. Topiramate appears to mute that response.

Some studies even show that topiramate can lower the number of binge eating episodes per week.

However, weight loss is highly personal, and individual results vary based on different factors.

Not losing weight on topiramate (Topamax)? Reasons why

Not everyone loses weight on Topamax, and the reasons for not losing weight on topiramate can vary from person to person. Understanding what might be influencing your results can help you have a more informed conversation with your healthcare provider.

1. Everybody is different

Topiramate reduces appetite for some people, but individual body chemistry plays a role in how well it works.

Underlying conditions, like insulin resistance, may limit results. Genetics plays a role. A healthcare provider can help determine whether a different approach or medication may be a better fit for you.

2. Your diet matters

Topiramate may reduce your hunger, but it does not automatically change food choices. Eating a balanced diet and managing portions remain important parts of the equation.

Sometimes the issue is not what you are eating, but why.

Also, sometimes the issue isn't what you're eating, but why. If stress, sadness, anxiety, or even boredom send you straight to the kitchen, these types of emotional eating cravings could override the effects of weight loss medications.

If you’re struggling with emotional eating triggers, you don’t have to fight them all alone. A registered dietitian who specializes in disordered eating patterns can help you identify triggers and build practical strategies to address them.

They can also help figure out which foods promote fullness, how to manage portions without feeling deprived, and how to handle situations like eating out or handling grocery budgets.

As always, talking to a healthcare provider is a good first step before making any significant changes to your diet.

3. Dosage

If you’re not losing weight on topiramate, you may need a dose adjustment. What works for one person won't necessarily work for another, and finding your right dose takes some trial and error. Please do not change your dose without approval from a healthcare provider.

3. Side effects of Topamax

Some of Topamax’s side effects may actually work against weight loss efforts. Brain fog and fatigue, for example, can make it harder to prepare meals or stay active. When energy and focus are low, it may be hard to prep and cook meals, grocery shop, or exercise.

4. Sleep

Poor sleep affects two key hormones that regulate hunger: ghrelin, which signals hunger, and leptin, which signals fullness.

Research has found that just 2 nights of limited sleep can raise ghrelin levels by around 28% and lower leptin levels by around 18%, leading to increased hunger and stronger cravings for high-calorie foods.

Over time, poor sleep also raises cortisol, the body's stress hormone, which may promote fat storage, particularly around the abdomen.

5. Stress

Chronic stress compounds the problem. Elevated cortisol (stress hormone) levels can increase appetite and make the body more resistant to weight loss, and even lead to belly fat, even when you’re taking a weight loss medication.

6. Exercise

Physical activity and regular movement support weight loss in ways that medication alone cannot. This includes preserving muscle, improving insulin sensitivity, and helping regulate mood (which could help with emotional eating or binges).

Note: Please talk to a doctor before starting a new exercise regimen.

Side effects of Topiramate(Topamax)

Common early side effects of Topamax (Topiramate) are:

• Tingling in hands and feet (paresthesia)
• Fatigue and appetite loss
• Dizziness

Additionally, Topamax can lead to brain fog, trouble concentrating, and memory loss. It’s why some people call it “Dopamax.”

Kidney stones are a documented risk of taking Topamax. Topiramate lowers urinary citrate, which normally prevents stone formation. Keto or very low-carb dieters may face a higher risk. Pain in your side or back, blood in urine, or painful urination needs same-day attention.

Topiramate is also linked to serious birth defects. For migraines, topiramate cannot be prescribed during pregnancy. Women of childbearing age are typically required to use effective contraception and test negative for pregnancy before starting it.

Talk to your healthcare provider to learn more about the side effects of Topiramate (Topamax).

Topiramate (Topamax) vs. Wegovy and Zepbound for weight loss

Topamax was never designed for weight loss. It's an anti-seizure and migraine prevention medication that causes weight loss as a side effect, which is why it's sometimes considered for weight management off-label.

However, Wegovy and Zepbound are different. These newer medications are approved by the FDA for weight loss (provided eligibility criteria are met).

Weight loss results

Research shows that people taking Zepbound lost 15% to 20% of their body weight over about 1.5 years (72 weeks). Those on Wegovy lost an average of 15% just over a year (68 weeks).

In comparison, Topamax has shown to result in roughly 5% to 7% weight loss over 6 months.

How they work

Zepbound and Wegovy work by mimicking natural gut-brain hormones that regulate hunger and fullness. They target the underlying biology of hunger, with weight loss as the main goal rather than a side effect. They also help prevent blood sugar spikes by stimulating the pancreas to release insulin at the start of a meal.

Topiramate, on the other hand, works mostly on the brain.

Administration

Zepbound and Wegovy are weekly injections, while topiramate (Topamax) is an oral daily pill.

Note: A healthcare provider can assess whether weight loss medication is appropriate and which option may be the best fit based on each person’s health condition and needs.

Final Thoughts

Topiramate may cause weight loss as a side effect. Results vary widely from person to person, and success depends on multiple factors, including your dosage, how your body responds to the medication, your eating habits, and your overall lifestyle.

The most important thing? 

Work closely with a healthcare provider to find the right approach for your situation. Also, a registered dietitian can make a difference in helping you develop sustainable eating habits that work with medication.

Frequently Asked Questions (FAQs)

Does everyone lose weight on Topamax?

Topamax may not result in weight loss for everyone. Weight loss results vary depending on dosage, genetics, adherence, lifestyle factors, and more. Talk to your doctor to learn if Topamax may work for you.

How long does it take to lose weight on topiramate (Topamax)?

Studies indicate a 5%-7% weight loss with Topamax (topiramate) over 6 months.

Is topiramate the same thing as Qsymia?

No. Topiramate is a single-ingredient medication to treat epilepsy and prevent migraines. It is not FDA-approved for weight loss. Qsymia combines topiramate and phentermine and is specifically approved by the FDA for weight loss.

How much weight can I lose on Topamax?

Clinical data show 5-7% weight loss in about 6 months. For example, someone weighing 200 pounds may lose 10-14 pounds.

Can Topamax cause kidney stones?

Yes, kidney stones are a side effect of Topamax (topiramate). Talk to your healthcare provider if you have any questions on side effects of topiramate (Topamax).

Can I drink alcohol on Topamax?

Drinking alcohol while taking Topamax is not recommended. Both substances affect the brain and central nervous system (CNS). So, combining them can make side effects like dizziness, sleepiness, and confusion worse. A healthcare provider can advise based on individual circumstances.

Can Topamax cause brain fog?

Yes, Topamax may cause brain fog as a side effect (which is why it’s sometimes informally known as ‘Dopamax’). Please consult your healthcare provider to learn more about the medication's side effects.

Does Topamax work the same as Ozempic?

No, Topiramate and Ozempic are completely different medications that work in different ways. Topiramate is an anti-seizure medication that's sometimes prescribed off-label for weight loss.  Ozempic (semaglutide) is a diabetes medication that mimics natural gut hormones to control blood sugar and reduce appetite. Topamax is an oral daily pill, while Ozempic is a weekly injection.

Should I take topiramate (topamax) in the morning or at night for weight loss?

Topiramate (Topamax) is not FDA-approved for weight loss. If your doctor prescribes it off-label, please follow their instructions on the best time to take it. Topiramate is also part of an approved weight loss medication called Qsymia, which combines topiramate and phentermine. Qsymia is typically taken once daily in the morning to avoid sleep disruption from the stimulant component. Always follow your healthcare provider’s recommendations for when to take your medication.

Does insurance cover Topiramate(Topamax) for weight loss?

Insurance coverage for Topamax depends on why it's prescribed. Most plans cover Topiramate to treat seizures or prevent migraines, but coverage is less likely for weight loss.

Qsymia, an approved weight loss drug that includes topiramate, may be covered by your insurance, depending on your individual health plan. Please work with your prescribing doctor and insurance provider to learn if insurance covers your treatment.

Find a weight loss dietitian near you, covered by your insurance. 

The views expressed by authors and contributors of such content are not endorsed or approved by Fay and are intended for informational purposes only. The content is reviewed by Fay only to confirm educational value and audience interest. You are encouraged to discuss any questions that you may have about your health with a healthcare provider.