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Does gabapentin cause weight gain?

It’s a side effect for a small percentage of people taking this anti-seizure medication

Key takeaways

  • Gabapentin is prescribed for nerve pain and seizures but may lead to weight gain in a small percentage of individuals.

  • Key mechanisms driving gabapentin weight gain include increased appetite, fluid retention, enhanced fat storage, slowed metabolism, and challenges with exercise.

  • Effective weight management strategies encompass medication reassessment, portion control, dietary changes, and regular exercise.

  • Alternative meds with a lower risk of weight gain include lamotrigine, levetiracetam, and topiramate.

Gabapentin (brand name Neurontin) is an anti-seizure medication that is primarily used to alleviate nerve pain and manage seizures. The prescription drug is FDA approved to control seizures in adults and children with epilepsy and treat a type of nerve pain called postherpetic neuralgia (PHN) that can occur after a shingles infection. It’s also used off-label to treat diabetic neuropathy, fibromyalgia, neuropathic pain from sciatica, alcohol dependence, and anxiety. An extended-release form of gabapentin is approved to treat restless legs syndrome.

Because it’s effective for many different nervous system and chronic pain disorders, gabapentin is commonly prescribed. But like all medications, gabapentin comes with the possibility of side effects, including one that may surprise you—weight gain. Here’s what to know if your weight changes on gabapentin.

Can gabapentin cause weight gain?

In clinical trials, the most common side effects of gabapentin in adults were drowsiness, dizziness, and edema (fluid retention) in the legs, feet, arms, and hands. While it’s not a common side effect, about 2% of patients taking gabapentin experienced weight gain, and 8% experienced fluid retention. Other potential side effects include:

  • Uncontrolled eye movements
  • Tremors
  • Weakness
  • Diarrhea or constipation
  • Dry mouth
  • Infection
  • Sore throat
  • Cough
  • Upset stomach, nausea, or vomiting
  • Loss of coordination
  • Blurred or double vision
  • Lazy eye
  • Depression
  • Memory problems
  • Weight gain

Serious side effects of gabapentin include suicidal thoughts and behaviors, muscle damage, slow breathing, withdrawal symptoms (if the medicine is stopped abruptly or too quickly), and severe allergic or skin reactions. Seek immediate medical attention if you experience any of these rare but possible side effects. 

This is not a full list of side effects, and others may occur. Consult your healthcare provider for more information about the potential side effects of gabapentin. 

RELATED: Gabapentin interactions to avoid

But exactly how does gabapentin cause weight gain? According to Sazan Sylejmani, Pharm.D., owner and pharmacy manager at Westmont Pharmacy in Illinois, gabapentin can affect your waistline by impacting:

  1. Appetite: One of the most significant ways gabapentin can cause weight gain is by stimulating appetite. Feeling hungrier often results in increased food intake and, consequently, weight gain.
  2. Fluid retention: Another factor to consider is that gabapentin may lead to fluid retention within the body. Excess fluid can result in temporary weight gain that may be misinterpreted as increased body weight.
  3. Fat storage: The medication can alter the body’s metabolic processes, leading to a greater propensity for fat storage rather than fat burning. This shift can contribute to an overall increase in body weight.
  4. Metabolism: Gabapentin may affect how efficiently the body metabolizes food. A slowed metabolic rate can make it more challenging for individuals to burn calories effectively, leading to potential weight gain over time.
  5. Energy levels: Side effects such as dizziness or fatigue, which some individuals experience while taking gabapentin, can make regular physical activity more difficult. Reduced motivation or ability to exercise can further exacerbate weight gain.

If you’re gaining weight while taking gabapentin, the medication could be the culprit, but it’s not the most likely scenario, emphasizes Raj Dasgupta, MD, internist and medical adviser for the National Council on Aging (NCOA).

“Weight gain is an uncommon side effect of gabapentin, and patients should evaluate other reasons for unwanted weight gain,” Dr. Dasgupta says. Lifestyle factors like an unhealthy diet, too much stress, not enough exercise, and insufficient sleep can make weight maintenance and weight loss more difficult.

RELATED: Gabapentin side effects in elderly patients

Does gabapentin make it hard to lose weight?

It can. Dr. Sylejmani says gabapentin can complicate weight loss efforts due to its effects on appetite regulation, metabolic activity, and energy levels. This combination of factors creates a challenging environment for those trying to maintain or reduce their weight.

Tips for managing your weight on gabapentin

To help manage weight and mitigate the risk of packing on the pounds while on anticonvulsant medications, Dr. Dasgupta recommends the following strategies:

  1. Exercise portion control: Practicing mindful eating and being aware of portion sizes can help regulate caloric intake and prevent overeating.
  2. Avoid or minimize processed foods and refined carbohydrates: Reducing the intake of processed foods like cookies, cakes, crackers, and white bread, which are linked to weight gain, while opting for healthier items like whole grains, lean protein, nuts, beans, fruits, and vegetables, can help stabilize blood sugar levels, thereby decreasing cravings for unhealthy snacks.
  3. Increase your protein intake: Consuming more protein can enhance feelings of fullness, which may help curb hunger and lower overall calorie consumption.
  4. Get regular exercise: Consistent physical activity can counterbalance the potential for weight gain and improve overall health and well-being. Consult your healthcare provider before beginning a new exercise program.
  5. Prioritize your sleep: Ensuring adequate sleep (seven to nine hours each night for adults) is crucial for effective weight management, as insufficient rest can disrupt hormones responsible for regulating appetite.
  6. Consider an alternative medication: Ask your healthcare provider about switching to a different medication that may have a reduced risk of weight gain.
  7. Consult your provider about a dose adjustment: If feasible, a lower dosage of gabapentin might alleviate some of the side effects, including heightened appetite or weight gain.

RELATED: What to avoid when taking gabapentin

Alternatives to gabapentin

While there is no proven algorithm for selecting an anticonvulsant for patients, Dr. Dasgupta says that several alternatives to gabapentin may be worth exploring for individuals who experience side effects. For example, medications such as lamotrigine, levetiracetam, and topiramate are known to have a lesser association with weight gain (and potentially fewer side effects). On the other hand, Dr. Sylejmani points out that some anticonvulsant medications, including valproate and carbamazepine, are typically linked to weight gain.

The bottom line? If gabapentin is causing weight gain, it is crucial to have a thorough discussion with a healthcare professional, such as a neurologist, to identify the most suitable and tolerated medication for your specific needs, urges Dr. Dasgupta.

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