Key takeaways

Topamax, originally approved for treating epilepsy and migraines, is also known to cause weight loss as a side effect, but is not FDA-approved for weight loss alone.
The weight loss effect of Topamax is attributed to its ability to reduce appetite and possibly increase metabolism, with clinical trials showing a weight loss of 6%-17% in patients.
While some may consider using Topamax off-label for weight loss, it carries risks, particularly for individuals with certain health conditions, and can lead to serious side effects including vision changes and metabolic acidosis.
In addition to Topamax, healthy lifestyle changes such as improving diet, regular exercise, reducing stress, and getting enough sleep are recommended as safe ways to lose weight and maintain weight loss.

Topamax is the brand name of a generic medication called topiramate. It’s an anticonvulsant medication that’s used to treat conditions like epilepsy, migraine headaches, and alcohol use disorder. Topamax is great for treating conditions like this, but many people who take it will experience weight loss as a main side effect. Let’s take a more in-depth look at how safe and effective Topamax is, and see how it’s related to weight loss.

Is Topamax approved for weight loss?

Topamax is approved by the Food and Drug Administration (FDA) to treat epilepsy and migraines, but the drug is also well known for causing weight loss. Even though weight loss may be a positive benefit of taking Topamax, the FDA hasn’t approved it for weight loss alone.

Topamax causes weight loss because it affects the appetite. People who take it and have a reduced appetite may feel hungry less often and eat less because of this. Studies have shown that Topamax may also speed up metabolism, which means that the body would be digesting food quicker than normal.

Clinical trials have shown that about 6%-17% of people who take Topamax will experience weight loss, and while many people may see this as an added benefit, losing too much weight isn’t a good thing. Dr. Kuldeep Singh, a top weight loss surgeon in the Baltimore Metropolitan area and Director of The Maryland Bariatric Center at Mercy Medical Center, says that most people will experience moderate weight loss from Topamax. Losing weight rapidly can be unhealthy, and it may be time to see a doctor if you’re taking Topamax and this happens to you. Maintaining a healthy weight is important, and the best way to find out what target weight is best for you is to ask your doctor. Falling below your target body weight because of Topamax would be another sign that it’s time to talk with your doctor.

Topamax dosage for weight loss

Because the use of Topamax for weight is off-label and truly a side effect of its use in clinical practice, no specific dose can be specified for this indication. Topamax’s weight loss side effect has resulted in its off-label use to treat binge eating disorders in adults, and the dosing for this indication does not differ greatly in comparison to other approved indications, ranging from 25mg per day to a maximum of 400mg per day. If used off-label for weight loss, the dose will likely begin low at 25mg to 50mg once daily and increase slowly over weeks until a benefit of weight loss is noted – balancing this desirable side effect with those which are less desirable. It is unlikely the dose of topiramate for the indication of weight loss needs to exceed 200 mg per day, as clinical trials have not demonstrated additional benefit in percent body weight lost beyond this dose. An extended-release formulation of topiramate co-formulated with phentermine is available as a product called Qsymia, which is indicated for chronic weight management. The dose of topiramate in this co-formulated product ranges from 23 mg once daily to a maximum of 96 mg once daily.

Is it safe to take Topamax for weight loss?

Sometimes Topamax can be prescribed off-label to help someone lose weight. Off-label prescribing happens when a doctor writes someone a prescription for a medication that’s approved by the FDA to treat a condition that’s different from what their patient has. This is legal and frequently happens in the medical industry, with an estimated 1 in 5 prescriptions being written off-label.

A doctor may choose to write someone a prescription for Topamax to help with their weight loss or to treat eating disorders like binging and purging that lead to weight gain. According to Dr. Singh, someone must have a body mass index (BMI) that’s 30 or higher in order to be prescribed any weight loss medication, including Topamax.

Studies have shown that people who take Topamax for weight loss lose about 11 pounds in comparison to placebo groups if they take the drug for at least four months, and that the weight loss effects of Topamax increase with both duration of treatment and dosage. Studies have also shown that topiramate treatment can increase the chance of statistically significant weight loss by more than sixfold.

Risks of using Topamax for weight loss

Even though Topamax can be very effective for weight loss, it isn’t safe for everyone. The following groups of people should talk with their doctor before taking Topamax because they may have an increased risk of experiencing serious adverse events if they take it:

People with kidney disease
People with lung disease or breathing problems
People with liver disease
People with eye problems such as glaucoma
People with depression
People with suicidal thoughts or behaviors
People with osteoporosis
People with metabolic ketoacidosis

It may be safe for pregnant women to take Topamax if the benefits of taking the medication outweigh its potential risks. Topamax can cause fetal harm and oral birth defects if it’s taken by pregnant women, which is why it’s prescribed with caution. It’s also excreted in human milk, but it’s unknown whether or not it will negatively impact breastfeeding infants. Topamax can make birth control pills less effective, so it’s important to talk with your doctor about using non-hormonal birth control methods if you don’t want to become pregnant while taking Topamax.

Side effects of using Topamax for weight loss

People who aren’t pregnant and who don’t have any of the health conditions mentioned above can safely take Topamax, but they may still experience side effects from taking it. Here are some of the most common side effects of Topamax aside from weight loss:

Dizziness
Tiredness
Numbness
Diarrhea
Loss of appetite
Loss of coordination
Paresthesia (burning sensations)

Although it’s rare, Topamax can cause more serious side effects that may require medical attention like confusion, memory problems, trouble concentrating, and trouble speaking. Some people will also experience mental health side effects like depression, panic attacks, mood changes, and suicidal thoughts or behaviors. If you have any of these symptoms, you should seek medical advice as soon as possible.

The other rare side effect of Topamax that’s worth mentioning is eye problems that can lead to vision changes and blindness, which is why it’s so important to call your doctor if your vision starts to change. This list of side effects is not comprehensive; if you’d like a complete list of Topamax side effects, you can always ask your doctor or pharmacist for a medication guide.

If Topamax is causing too many side effects for you, know that you have other options. The active ingredient in Topamax, topiramate, is the main ingredient in the weight loss drug Qsymia, which also contains phentermine. According to Dr. Singh, Qsymia is one of the best medications to use long-term in combination with diet and lifestyle changes for weight loss, especially for obese patients with class 1 or class 2 obesity. So if you’re not able to take Topamax because of an underlying health problem or because you’re experiencing too many adverse effects, you might try asking your doctor about Qsymia or other ways to lose weight.

How to take Topamax to lose weight

Topamax can be taken to promote weight loss and help control binging and purging, but it’s important to remember that it isn’t a substitute for going to a doctor and creating a well-rounded weight loss plan. If you’re interested in taking Topamax, it’s best to schedule an appointment with your doctor to see if it’s right for you. Your doctor will do a complete physical exam and ask about your medical history. If you and your doctor decide that Topamax can safely help you lose weight, then you may receive a prescription for it.

If you do receive a prescription from your doctor, it’s important to know how to take Topamax to get the best results. The starting dose of Topamax for weight loss is a low dose of 25 mg per day, but this dosage strength can be increased on a case-by-case basis based on each individual’s medical history and how much weight they have to lose.

In a study done by the Journal of Clinical Psychiatry, bipolar and schizophrenic patients who were given an average dose of 195 mg of topiramate per day lost about 22 pounds over time. This just goes to show that the range of Topamax dosages can vary from low to high and that doctors may increase or decrease the amount of Topamax that someone takes over time-based on the results they are or aren’t getting.

It can take some time to see weight loss results from taking Topamax. Some people may not notice a difference until they’ve taken the drug for at least four months, while other people may start to lose weight in their first month of taking it. Weight loss results from topiramate are proven to increase over time.

Topamax can be taken with or without food and is generally taken at the same time each day. It shouldn’t be taken at the same time as certain other medications because of the potential for drug interactions. Here’s a list of medications Topamax shouldn’t be taken with:

Antiepileptic drugs
Carbonic anhydrase inhibitors
CNS depressants
Oral contraceptives
Hydrochlorothiazide (HCTZ)
Pioglitazone
Lithium
Amitriptyline

In addition to these medications, Topamax shouldn’t be taken with alcohol because this can cause sleepiness, increase the risk of getting kidney stones, and cause metabolic acidosis. Metabolic acidosis is a condition where too much acid builds up in body fluids, and it can become life-threatening if it goes untreated. If you start to experience rapid breathing, confusion, extreme tiredness, and an increased heart rate while taking Topamax, you should seek medical attention as soon as possible because these are signs that you may have metabolic acidosis.

Related: Saxenda for weight loss

Weight gain after Topamax

When someone stops taking Topamax, it’s possible that they might experience some weight gain over time, especially if they haven’t been combining Topamax with healthy lifestyle changes. In an observational study done by the National Library of Medicine, discontinuation of Topamax for at least six months showed a trend for returning to a baseline weight. So people may be more likely to return to what they weighed before they started taking Topamax, but this may take some time.

This return to a baseline weight may happen because the body is no longer experiencing a reduced appetite and faster metabolism. The best way to make sure you’re able to keep weight off after stopping Topamax is to adopt healthy lifestyle changes that will support you on your weight loss journey.

5 safe ways to lose weight

Topamax can be helpful on your weight loss journey if your doctor approves it, but it’s not the only way to lose weight. Lifestyle changes can help you lose weight and keep it off so that you can enjoy the benefits of weight loss without taking Topamax, while taking it, or after taking it. Here are some of the safest ways to lose weight.

1. Improving your eating habits

Eating healthy is one of the safest and best ways to lose weight. Being mindful of what and how much you’re eating can help you lose weight if you do it right. For the best advice on what to eat to lose weight, you should talk with your doctor, but making some small changes like eating more fruits and vegetables can be a great way to start.

Processed foods, refined carbohydrates, sugar, and alcohol are all examples of foods that can cause weight gain. Fresh fruits, vegetables, and high-quality proteins like salmon, beans, and eggs are all great examples of foods that the body can easily process and get vital nutrients from.

2. Exercising regularly

According to the Centers for Disease Control and Prevention (CDC), exercise not only helps control weight, but it reduces high blood pressure, reduces the risk of getting Type 2 diabetes, and can even reduce the symptoms of depression and anxiety. People vary in how much physical exercise they need to lose weight, so it’s a good idea to talk with your doctor about how often you should be exercising. Some great exercises for weight loss include walking, biking, swimming, and weight training.

3. Reducing stress

Stress is linked to many health problems, such as anxiety and depression, but it’s also been linked to unexpected weight gain. Feeling stressed out can lead to emotional eating, which can lead to weight gain over time. Finding ways to reduce stress may help you lose weight. You might try meditating, yoga, going for walks in a park, or calling a friend or family member. You can also ask your doctor or a counselor for proven ways to reduce stress that might fit into your lifestyle.

4. Getting enough sleep

According to the Sleep Foundation, a lack of sleep may increase the appetite and lead to metabolic problems. Getting enough sleep can help your body function properly and give you more energy to do things like exercise, which will help you lose weight. Getting enough sleep can also reduce your stress levels, which will help you control any urges you might get to overeat.

5. Trying safe diet pills & supplements

There are countless diet pills and supplements on the market that claim to cause weight loss, such as Hydroxycut and glucomannan, but they shouldn’t serve as a substitute for healthy lifestyle changes. “When people go for weight loss medications, most of them do it because it’s easy to do,” says Dr. Singh. “If somebody seriously changes their lifestyle and eating habits first, they will really see a solid improvement with Topamax or other weight loss medications. The mindset is the most important thing. Medications cannot serve as a substitute for proper eating and exercising habits,” says Dr. Singh.

Frequently asked questions about Topamax and weight loss

Can Topamax cause rapid weight loss?

Because the weight loss seen with Topamax is related to a decrease in appetite, you won’t begin to see weight loss for a few weeks, if not a couple of months. In addition, the weight loss with Topamax is unlikely to be drastic—most studies have shown a decrease in Body Mass Index (BMI) around the 5-10% mark.

How much Topamax should I take to lose weight?

For all indications, the Topamax dose is usually started low and increased slowly over time so as to be able to monitor for the onset of unwanted side effects. Clinical studies have shown a plateau of this side effect approaching a dose of 200mg per day, meaning patients exceeding this dose did not demonstrate greater weight loss.

How long does it take to lose weight on topiramate?

Weight loss by Topamax can be noticed within weeks of starting the medication as it decreases appetite and potentially stimulates metabolism. The additional benefit of Topamax in comparison to other weight loss medications on the market is that there does not seem to be a plateau of weight loss at six months, so the weight loss may be an ongoing effect.

What is the difference between phentermine and topiramate?

Phentermine is a sympathomimetic medication that is specifically indicated for weight loss. Aside from its FDA-approved indication, due to its mechanism of stimulating the central nervous system, the main difference between the two medications is that phentermine should only be used short-term.

What is the best weight loss pill?

The best weight loss pill should be individualized to a person since so many weight loss medications are approved to be used to manage additional conditions. Some medications that help manage Type 2 diabetes with a side effect of weight loss make more sense to use in a diabetic patient, whereas topiramate might be best suited for someone that suffers from migraines and needs to lose a little weight. While weight loss might be considered a beneficial side effect, it might not be in all patients; in addition, the other side effects of these medications should be considered in case they won’t jive with a person. Any decision on weight loss medications should be made in conjunction with a healthcare professional with a good understanding of all of a patient’s needs and conditions.