Does Gabapentin Cause Weight Gain?

gabapentin weight gain
Medically reviewed by Richard Honaker M.D.

Overview

It is important to understand how medications impact our bodies, including potential side effects like weight gain. Gabapentin, first approved in the 1990s to treat epilepsy and nerve pain, has since become a versatile drug, also used for conditions like anxiety and insomnia. However, as its use has grown, so have concerns about its side effects. One notable concern is weight gain.

When Gabapentin was first released, its efficacy and low occurrence of side effects were highly acclaimed. However, as more people started using it, weight gain stories began to appear. Studies have shown that some patients on Gabapentin experience an increase in weight, potentially due to increased appetite or water retention. The exact reason remains unclear, but the correlation is strong enough to warrant attention.

Gabapentin can provide significant relief for various conditions; patients and doctors should be well aware of potential side effects like weight gain. Balancing the benefits and risks is critical to making informed decisions about its use.

Does gabapentin cause weight gain?

Gabapentin side effects are uncommon; however, weight gain is still a possibility. A small proportion of people taking the medicine, which is used to treat epilepsy and postherpetic neuralgia, had weight gain, according to studies. Those who gain weight may gain up to five pounds after using the product for six weeks.

Here is an example of Arthur, a 38-year-old man who started taking Gabapentin for chronic nerve pain. Over six months, he gained 15 pounds despite no changes in his diet or activity level. This unexpected weight gain added stress and affected his overall well-being, highlighting the need for awareness and careful monitoring.

Clinical Trials and Reports

Some clinical trials and patient reports have noted weight gain as a side effect of Gabapentin use. The extent of weight gain can vary widely among individuals, with some experiencing significant increases and others noticing little to no change. For example, a study found that a subset of patients using Gabapentin reported weight gain, although the increase was generally modest.

Comparative Studies

Comparative studies with other medications have shown mixed results. Some suggest that Gabapentin has a higher tendency to cause weight gain compared to placebos or other drugs, while others indicate that weight gain is a relatively rare side effect.

How does gabapentin cause weight gain?

“Gabapentin, while primarily prescribed for neuropathic pain and seizures, has been associated with weight gain in some patients. This side effect can vary in severity, often depending on dosage and individual patient factors.” Says Dr. Richard Honakar 

Gabapentin can cause weight gain through multiple mechanisms, including increased appetite, metabolic changes, water retention, and reduced physical activity. Understanding how gabapentin causes weight gain involves exploring its mechanisms of action and the various factors that contribute to this phenomenon.

Mechanisms Behind Gabapentin-Induced Weight Gain

Gabapentin-induced weight gain may result from increased appetite and fluid retention. Additionally, the drug can cause changes in metabolism and reduce physical activity due to its sedative effects. These are explained in detail below.

Increased Appetite

Central Nervous System Effects: Gabapentin acts on the central nervous system by binding to voltage-gated calcium channels, which can affect neurotransmitter release. This action may alter appetite-regulating pathways in the brain, leading to an increase in appetite. Patients may find themselves eating more than usual, contributing to weight gain.
Behavioural Changes: Gabapentin’s relief from pain or anxiety might improve a patient’s overall mood and appetite, leading to increased food intake. In contrast, pain or anxiety often suppresses appetite, so alleviating these symptoms can have the opposite effect.

Metabolic Changes

Metabolism Impact: Gabapentin may slow metabolism, causing the body to burn calories less efficiently. While the exact mechanism is not fully understood, this metabolic shift can contribute to gradual weight gain as the body stores more calories as fat.

Hormonal Effects: Some studies suggest that gabapentin can influence hormone levels that regulate metabolism and fat storage, though this area requires more research to reach definitive conclusions.

Water Retention

Fluid Retention: Gabapentin can cause the body to retain water, leading to weight gain unrelated to fat accumulation. This effect is due to the medication’s impact on kidney function and fluid balance. Patients might notice swelling in their limbs or an overall bloated feeling.

Short-Term vs. Long-Term: Water retention can cause rapid weight gain shortly after starting gabapentin. Over time, however, the body may adjust, and this weight gain may stabilize or diminish.

Reduced Physical Activity

Pain Management: While gabapentin is effective in managing pain, which might enable more physical activity, it can also cause side effects like dizziness and fatigue. These side effects can reduce a patient’s ability to exercise, leading to decreased caloric expenditure and weight gain.

Sedation and Fatigue: Gabapentin often causes sedation and fatigue, making patients less likely to engage in physical activities. This decrease in activity level can contribute to weight gain over time.

Are you concerned that you are gaining weight while taking gabapentin?

What other medications can cause weight gain?

Several medications are known to cause weight gain as a side effect. These include various types of drugs used to treat different conditions, such as psychiatric disorders, diabetes, high blood pressure, and more. Here’s a detailed look at some of the medications that can contribute to weight gain:

Psychiatric Medications

Antidepressants

  • Selective Serotonin Reuptake Inhibitors (SSRIs): Some SSRIs, like paroxetine (Paxil), can cause weight gain.
  • Tricyclic Antidepressants (TCAs): Medications like amitriptyline (Elavil) and nortriptyline (Pamelor) are known for their weight gain potential.
  • Monoamine Oxidase Inhibitors (MAOIs): These include phenelzine (Nardil) and tranylcypromine (Parnate).

Antipsychotics

  • Atypical Antipsychotics: Drugs like olanzapine (Zyprexa), risperidone (Risperdal), quetiapine (Seroquel), and clozapine (Clozaril) are particularly notorious for causing weight gain.
  • Typical Antipsychotics: Some older antipsychotics, such as haloperidol (Haldol), can also contribute to weight gain, though typically less than the atypical antipsychotics.

Mood Stabilizers:

  • Lithium: Often used to treat bipolar disorder, lithium is associated with significant weight gain.
  • Anticonvulsants: Medications like valproate (Depakote) and carbamazepine (Tegretol), used for mood stabilization, can also cause weight gain.

Diabetes Medications

Insulin

  • Various forms of insulin, used to manage blood sugar levels in diabetes, can lead to weight gain due to increased appetite and the anabolic effects of insulin-promoting fat storage.

Sulfonylureas

  • Glipizide (Glucotrol) and glyburide (Diabeta, Micronase) stimulate insulin production, leading to weight gain.

Thiazolidinediones

  • Medications like pioglitazone (Actos) and rosiglitazone (Avandia) improve insulin sensitivity but can cause fluid retention and weight gain.

Antihypertensives

Beta-Blockers

  • Medications such as metoprolol (Lopressor) and atenolol (Tenormin) can cause weight gain, likely due to reduced metabolic rate and decreased physical activity.

Alpha-Blockers

  • Drugs like prazosin (Minipress) and terazosin (Hytrin) used for the cure of benign prostatic hyperplasia (BPH) and high blood pressure might also contribute to weight gain.

Steroids

Corticosteroids

  • Prednisone and dexamethasone, for example, are well-known for their ability to increase hunger and cause fluid retention, which can result in weight gain when taken for autoimmune and inflammatory disorders.

Hormonal Medications

Hormonal Contraceptives

  • Gaining weight is a possible side effect of some birth control methods, especially those that contain progesterone and estrogen.

Hormone Replacement Therapy (HRT)

  • HRT used for menopause symptoms can also cause weight gain in some women.

Antihistamines

First-Generation Antihistamines

  • Medications like diphenhydramine (Benadryl) and hydroxyzine (Atarax, Vistaril) can cause weight gain, likely due to their sedative effects and impact on appetite regulation.

Anti-Epileptic Drugs

Gabapentin (Neurontin):

  • As discussed, gabapentin is associated with weight gain.
  • Pregabalin (Lyrica): Similar to gabapentin, pregabalin can also cause weight gain.

Migraine Medications

Beta-Blockers:

  • Used for migraine prevention, these can lead to weight gain, as mentioned earlier.
Notice an increase in weight? It could be due to your gabapentin.

How to avoid weight gain on gabapentin?

While using gabapentin, try to avoid, stop, or reverse weight gain by eating a balanced diet, controlling your stress levels, exercising frequently and getting enough sleep. Track your weight regularly and collaborate closely with your physician to modify your treatment plan as necessary. By taking a proactive and all-encompassing strategy, you may take advantage of gabapentin’s therapeutic properties and efficiently manage your weight. Here are some effective strategies:

Dietary Changes

Balanced Diet: Eat various foods, including fruits, vegetables, lean proteins, and whole grains. These provide essential nutrients and help you feel full longer.

Portion Control: Pay attention to portion proportions to prevent overindulging. Smaller bowls and plates can help manage portions.

Limit Sugary and High-Fat Foods: Restrict your intake of foods high in fat and sugar, such as sugary snacks, candies, fast food, and fried foods.

Healthy Snacks: Choose healthy snacks like vegetables, fruits, nuts, and yogurt instead of processed snacks.

Hydration: Sip lots of water during the day. Sometimes, people confuse thirst with hunger, which causes them to overeat.

Mindful Eating: Pay attention to your body’s signals of hunger and fullness, eat deliberately, and relish every bite of food. These techniques help you avoid overindulging.

Regular Physical Activity

Aerobic Exercise: Take part in frequent aerobic exercises like cycling, swimming, running, or walking. 

Strength Training: Include strength training activities twice a week. Gaining muscular mass can help you burn more calories and speed up your metabolism.

Consistency: Make physical activity a regular portion of your routine. Consistency is key to managing weight effectively.

Lifestyle Modifications

Sleep Hygiene: Get enough sleep. Insufficient sleep can disrupt hunger hormones and result in weight gain. Try to get seven to nine hours each night.

Stress Management: Manage stress through deep meditation, breathing exercises, and yoga. Stress can cause weight gain and emotional eating.

Regular Monitoring: Monitor any changes in your weight regularly. This might help you spot patterns and modify your diet and exercise regimen as necessary.

Medical and Professional Guidance

Medication Review: If there has been a noticeable increase in weight, talk to your doctor about the potential of changing the gabapentin dosage or moving to an alternate drug.

Professional Support: Consider consulting a dietitian or nutritionist who can assist you in developing a customized weight-management strategy.

Appetite Suppressants: Sometimes, healthcare providers may prescribe appetite suppressants or other medications to help manage weight gain.

Behavioural Strategies

Mindful Eating: Eat mindfully to avoid overindulging by observing your body’s signals of eating mindfully, hunger and fullness, and savouring every bite.

Support Systems: Join a support group or find a weight management program that can provide encouragement and accountability.

Supplements and Alternatives

Nutritional Supplements: After consulting with your healthcare provider, consider supplements that support metabolism, such as green tea extract or fibre.

Alternative Therapies: Explore alternative therapies like acupuncture or cognitive-behavioural therapy (CBT) for pain management or anxiety, which might reduce the need for higher doses of gabapentin.

An alternate medication, might be your solution to the weight gain caused by Gabapentin.

When should I see a doctor?

Some people may gain weight while taking gabapentin; this is usually the result of increased appetite and fluid retention. You should consult a physician if you gain weight suddenly or significantly or if it’s accompanied by symptoms like breathing difficulties or edema.

FAQs about gabapentin weight gain

What can I take instead of gabapentin for nerve pain?

Alternative medications for nerve pain include pregabalin, amitriptyline, and duloxetine. It’s essential to consult with a doctor to determine the most appropriate treatment based on your specific condition and medical history.

Is there an over-the-counter equivalent to gabapentin?

There is no direct over-the-counter equivalent to gabapentin. However, some patients may find relief from mild nerve pain with OTC pain relievers like acetaminophen or ibuprofen, but these are not specifically designed for neuropathic pain.

Will I lose weight if I stop gabapentin?

Some patients may experience weight loss after discontinuing gabapentin, particularly if the medication is the cause of weight gain. However, weight changes can vary based on individual health factors and lifestyle.

Does gabapentin make you bloated?

Gabapentin can cause bloating in some individuals as a side effect. This is typically related to fluid retention and gastrointestinal changes induced by the medication.

Your Doctors Online uses high-quality and trustworthy sources to ensure content accuracy and reliability. We rely on peer-reviewed studies, academic research institutions and medical associations to provide up-to-date and evidence-based information to the users.

  • Evaluating Gabapentin Dosing, Efficacy and Safety in Infants.
  • Guttuso Jr, Thomas, et al. “Effect of gabapentin on hyperemesis gravidarum: a double-blind, randomized controlled trial.” American journal of obstetrics & gynecology MFM 3.1 (2021): 100273.
  • Ghusn, Wissam, et al. “Weight-centric treatment of depression and chronic pain.” Obesity Pillars 3 (2022): 100025.
  • Anticonvulsant Agents: Gabapentin and Pregabalin
  • McIntyre, Roger S., et al. “Psychotropic Drug–Related Weight Gain and Its Treatment.” American Journal of Psychiatry 181.1 (2024): 26-38.

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