Topamax (Topiramate) is an anticonvulsant medication that is primarily used for the treatment of epilepsy, but has also been approved for migraine prevention and as an adjunct to phentermine for weight loss. It is also commonly used as an off-label medication to treat bipolar disorder as well as borderline personality disorder, but there is no conclusive evidence to support its efficacy in these conditions.
Despite the drug being effective in reducing the prevalence of seizures, its mechanism of action that produces therapeutic effects is unknown. Some speculate that it alters voltage-gated sodium channels as well as various calcium channels within the brain. Others believe that it may affect GABA receptors, AMPA receptors, and carbonic anhydrase isoenzymes.
Topamax & Weight Loss
Regardless of how the drug works, it is known that it is often used as an off-label pill to lose weight. Although not everyone will lose weight from taking Topamax, many people lose a significant amount throughout their treatment. It is also important to mention that although it isn’t approved as a standalone drug for weight loss, it is included in the formulation known as “Qsymia” which is approved specifically for weight loss.
How Topamax Works for Weight Loss
The mechanism behind how Topamax works is relatively misunderstood. It has been tested in clinical trials for weight loss, but was inevitably discontinued as a result of people experiencing a significant number of adverse effects. Although the drug never lasted in clinical trials for weight loss, many doctors are knowledgeable that patients taking Topamax are likely to lose some weight. Below is a list of factors that may influence how Topamax works to promote weight loss.
- Addiction centers of the brain: It is speculated that Topamax may be targeting the addiction centers of the brain with its mechanism of action. Individuals that previously sought out pleasure-inducing substances like food, alcohol, and drugs no longer do so. This is because Topamax may change neural pathways within the addiction control center of the brain. It may also reduce overexcited nerves within this region.
- Appetite reduction: Many people taking this drug experience appetite reduction or suppression as a side effect. It isn’t exactly known as to how this drug may supress appetite, but some believe it ties into the reward center of the brain. The drug may numb or alter the way rewards are processed, leading to people feeling less hungry or experiencing less cravings for food.
- Hormone alterations: Another school of thought suggests that the drug may be altering levels of hormones such as cortisol and leptin. Specifically the drug may be decreasing the amount of leptin that is found in cortisol, as well as cortisol itself. Leptin is a hormone that regulates appetite, and when reduced, people tend to feel less hungry. Also when cortisol (the stress hormone) is reduced, the body tends to store less fat, which will lead to weight loss.
- Disorientation: Those that take Topamax may feel so disoriented as a result of their treatment, that they may have a difficult time functioning and remembering to actually eat. While this may sound silly, this drug can have potent effects on memory, lead some people to feel dizzy, and result in profound disorientation. Those that feel disoriented as a result of treatment may forget to eat or may not want to eat as much.
- Ketosis: This drug may also be affecting levels of blood glucose as well as insulin, which could promote ketosis, a state by which the body uses its own fat as fuel. When in ketosis, your body uses up fat stores to give you energy, often resulting in significant weight loss. This is how individuals on “low carb” diets lose weight. Some speculate that Topamax may artificially induce ketosis.
- Loss of taste sensation: Many people notice that food loses its pleasurable taste and the “yum factor” seems to be missing while medicated. This typically leads people to eat smaller portions and/or less overall food. Some have complained that Topamax makes food taste bland, “grey,” flavorless, and in some cases just “bad.” If your taste buds feel like they’ve been hijacked, it’s a result of the drug.
- Metabolism changes: While many people don’t believe that Topamax speeds up the metabolism, some do. If you have maintained the same diet pre-drug as during treatment, and aren’t doing anything noticeably different, but are losing weight, it could be a result of a faster metabolism. This theory is less likely to be true due to the fact that this isn’t a psychostimulant medication, but one that should be considered.
- Saliva production: A specific theory as to why Topamax reduces ability to taste has to do with reduced saliva production. Those that take the drug tend to experience reductions in the amount of saliva produced on a daily basis. When saliva is reduced, it can result in poorer taste and people may lose some of their normal appetite – leading to weight loss.
- Side effects: Many people experience drug-related side effects that can also contribute to weight gain. Common effects that lead to weight loss include: diarrhea, nausea, and vomiting. If you are experiencing diarrhea and/or vomiting, it’s a no brainer that weight loss is inevitable. If you are nauseous all the time, you probably won’t want to eat as much; this is common sense.
Note: What leads to weight loss in one person may not be the same as in another. Therefore it is important to understand that certain factors may be more influential in one person’s weight loss than another. For example, one person may predominantly experience poorer taste, while another may have a reduced appetite and diarrhea.
Factors that influence weight loss on Topamax
There are other factors that may influence weight fluctuation as a result of Topamax treatment. These include things like: the dosage you ware taking, time span over which you’ve been taking it, your lifestyle and general habits, genetics, as well as other medications that you take.
It is known that this drug tends to help people lose weight, and there is a relationship between weight loss and the dosage taken. Those that take higher doses, tend to lose more weight than those on lesser doses. It should be speculated that dose in relationship to bodyweight as well as tolerance may also play a role. For a smaller statured individual, less of a dose may produce more weight gain than the same dose in a larger person.
Doctors will generally prescribe specific dosages based on the condition for which you are taking the drug. Those that are on Topamax for seizure prevention are likely to be on a higher dose than those for migraine prevention. The lower the dose, the less physiological influence the drug will have, leading to less weight change. If your goal is to avoid weight loss, you should be taking the “minimal effective dose.”
2. Time Span
The duration over which you’ve been taking Topamax can also play a role in determining how much weight you’ve lost. Someone who has been on the drug for a week and is just adapting to its effects may not experience as much weight change as someone who has taken it for several months. Over the short-term, you’re less likely to notice weight fluctuations in comparison to when you’ve taken it for a few months.
Those that have been on the drug for an extensive period may notice that weight loss stops once tolerance is developed. At a certain point, you’re likely to reach a peak in the amount of weight you lose simply due to the fact that your body will adapt to the drug.
3. Lifestyle / habits
Many people end up losing varying degrees of weight while on Topamax due to lifestyles and habits. Someone who isn’t getting proper sleep, is over-stressed, is eating junk food, and avoiding exercise may not lose as much weight as someone who is doing the opposite.
If you are eating healthy, getting a little bit of exercise each day, are sleeping well, and keeping stress to a minimum, you may be more likely to lose weight. Daily habits account for many individual differences in amount of weight lost while taking this drug.
While we don’t know exactly how this drug interacts with a person’s genetics, many genetic factors determine how much weight you’re likely to lose in comparison to someone else. Certain people may experience considerable weight loss from this drug, while others may remain weight neutral or even experience weight gain.
These differences in reactions may be partially explained by genetic variation. Fortunately there is new technology in development like GeneSight that predicts how you’ll react to drugs like Topamax.
5. Other drugs
If you are taking other medications, it is important to consider interaction effects as well as how they may influence your weight. For example, if you are on an SSRI or antipsychotic, you may be more likely to eat more food, regardless of how dull Topamax makes your taste buds. Any medications that make you more inclined to eat typically offset the weight loss effects of Topamax.
It should also be mentioned that if you are on stimulant-related medications such as Adderall or Wellbutrin, you may end up experiencing a synergistic weight loss effect. In other words, since you will be on multiple medications that can cause weight loss, the amount of weight you lose will be more significant than if you were just taking Topamax as a standalone treatment.
Should you use Topamax just for weight loss?
Probably not. Obviously this isn’t a medically accepted use of the drug, and most doctors wouldn’t allow it. If you were specifically struggling with weight, they may prescribe Qsymia, which contains Topamax as part of its formulation. Many people that struggle with seizures and are overweight typically are taking the drug primarily for seizure reduction, but may be pleasantly surprised when they also lose weight.
If you are using this drug just to lose weight, it may be difficult to put up with some of the neurological side effects such as memory impairment, dizziness, etc. While some people are willing to take any drug in order to lose weight, you really should be weighing the pros and cons before sacrificing mental performance in order to look skinnier.
Topamax weight loss dosage…
Some research suggests that there is an ideal daily dosage of Topamax specifically for weight loss. Those that consistently take between 100 mg and 200 mg of Topamax daily, have reported that weight loss is virtually effortless. Most people taking the drug within this dose range (assuming they aren’t on other treatments) end up losing between 15% and 20% of their baseline bodyweight. Some speculate that dosages above 200 mg may result in more drastic weight loss.
Will everyone lose weight from taking Topamax?
Not everyone is guaranteed to lose weight on this medication. There is a lot of individual variation such as diet, habits, genetics, other medications, etc. that can have a huge impact on someone’s weight. That said, it is estimated that weight loss is among the most common side effects of the drug Topamax.
Most evidence suggests that weight loss occurs among 11% and 26% of those taking the drug. It should be mentioned that a select number of individuals can experience a counterintuitive reaction of weight gain during their treatment, but this is very uncommon.
Topamax’s therapeutic effect vs. unwanted weight loss
Those that are taking the medication for the purpose of treating a condition like Bipolar disorder may not like the weight loss. If you are already relatively skinny, you may have a problem with looking even skinnier. Although most people look forward to losing weight while on a medication, not everyone shares that perspective. If you are losing a ridiculous amount of weight on this drug and don’t like it, be sure to talk to your doctor about other options and/or Topamax withdrawal.
Also if you like the weight loss, but find the drug ineffective for the primary condition for which it was intended to treat, you’ll likely need to try something new. Others may find the drug effective for treating a condition, and may like the weight loss, but the other side effects such as memory loss may be too profound to justify continued usage. Always evaluate how you’re doing on the drug throughout your treatment.
Did you lose weight while taking Topamax?
If you are a person that has taken Topamax and lost weight, be sure to share your story in the comments section below. It may help others to know the dosage you took, how long you were on the drug, as well as how quickly you noticed the weight loss. Be sure to mention why you think the drug caused you to lose weight (e.g. lost your appetite) and other potential lifestyle factors that may have also contributed to your weight loss.