Can medications or supplements cause weight gain?

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Lamictal and Weight Gain

Lamictal (lamotrigine) is weight-neutral and does not cause weight gain, making it a preferred antiepileptic choice when weight concerns are present. 1

Weight Profile of Lamotrigine

  • Lamotrigine is classified as a weight-neutral antiepileptic drug (AED), distinguishing it from other antiepileptics that commonly cause weight gain 1
  • This weight-neutral profile makes lamotrigine an excellent alternative when switching from weight-promoting antiepileptics 1

Antiepileptic Drugs That DO Cause Weight Gain

For context, the following antiepileptic medications are associated with significant weight gain and should be avoided or minimized when weight is a concern:

  • Valproate/valproic acid - associated with weight gain 2, 1
  • Carbamazepine - promotes weight gain 1
  • Gabapentin - causes weight gain 2, 1
  • Pregabalin - associated with weight gain 2, 3

Clinical Implications

When prescribing antiepileptic medications, consider the medication's effect on weight and minimize those associated with weight gain whenever possible. 2

  • If a patient is currently on a weight-promoting antiepileptic (such as valproate, gabapentin, or pregabalin), switching to lamotrigine can be considered as a weight-neutral alternative 1
  • This is particularly important for patients with obesity, diabetes, or metabolic syndrome where weight gain would worsen comorbid conditions 2, 4

Other Weight-Neutral or Weight-Loss Promoting Antiepileptics

  • Topiramate - may induce weight loss and can even be used to counteract weight gain from other medications 2, 1
  • Zonisamide - may induce weight loss 1

Common Pitfall

Do not confuse lamotrigine with other antiepileptics that cause weight gain. The weight profile varies dramatically across the antiepileptic class, and lamotrigine stands out as one of the few truly weight-neutral options in this medication category 1.

References

Research

Drug-induced weight gain.

Drugs of today (Barcelona, Spain : 1998), 2005

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Management of Medication-Induced Weight Gain.

Gastroenterology clinics of North America, 2023

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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