Skip to Content

Can Prescription Drugs Lead to Weight Gain?

Medically reviewed on Aug 22, 2017 by L. Anderson, PharmD.

Is It A Myth That Medications Can Cause Weight Gain?

No, this is not a myth. Weight gain due to medications can be just a few pounds, or it can be a more serious weight gain.

For example, some drugs that decrease inflammation like prednisone or methylprednisolone might lead to a 50 pound weight gain or more, often in the storage of fat.

In addition, weight gain from medications can lead to - or worsen - medical conditions such as:

  • high blood pressure
  • heart failure
  • type 2 diabetes
  • high cholesterol levels
  • arthritis

How Do Medications Cause Weight Gain?

Weight gain can be a slow process, whether it be from drugs, food, or lack of exercise. Exactly what causes the weight gain due to a medication is not always known. Some medications can increase hunger or lead to fluid and water retention. Some medications may slow you down and lead to a less active lifestyle, resulting in added pounds.

Drugs that trigger an increase in appetite may work in the brain and change the satiety (feeling full) center. It is often difficult to tell the difference between weight gain from a drug and weight gain from other reasons.

What Are The Risks Associated With Medication-Related Weight Gain?

The risks can be serious. Weight gain may increase the chance for high cholesterol, hypertension (high blood pressure), and type 2 diabetes. If a rapid weight gain occurs in a short period of time, a physician should be contacted for evaluation, especially if a patient has a risk for heart disease or high blood pressure.

Some drugs will need to be stopped slowly; stopping them quickly may lead to serious side effects. Patients should not stop taking any medication without first talking to their doctor.

What Can Be Done About Weight Gain With Medications?

If a patient is concerned about weight gain due to their medications, they should contact their health care provider. It may be possible to change to a different drug. Even similar medications in the same drug class can lead to very different side effects.

Medications can affect each patient differently, too - not every patient will gain weight, even if it is listed as a side effect of the drug. However, in some cases, patients will need to increase their level of exercise and adjust their diet.

Can Antidepressant Drugs Lead To Weight Gain?

Older antidepressants known as tricyclic antidepressants (TCAs) are known for increasing appetite and causing weight gain. The selective serotonin reuptake inhibitors (SSRI) class is usually weight neutral, but some drugs in this class can cause weight gain. A physician can choose among many alternatives in the antidepressant class to minimize weight gain.

Antidepressants are not always the direct cause of weight gain - lack of exercise, older age, unhealthy food choices, and changes in eating habits with depression may result in added weight, too.

Which Antidepressants Are Known To Cause Weight Gain?

Tricyclic antidepressants have been associated with weight gain - this class includes: amitriptyline, nortriptyline, and doxepin.

The serotonin boosters:

  • paroxetine (Paxil)
  • mirtazapine (Remeron)

have also been linked to weight gain in many studies. Other serotonin drugs, such as:

  • fluoxetine (Prozac)
  • sertraline (Zoloft)
  • venlafaxine (Effexor)
  • duloxetine (Cymbalta)

are more weight neutral.

Bupropion (brand names include Forfivo XL, Wellbutrin SR, Wellbutrin XL, ) is an antidepressant that may actually be linked with weight loss as a side effect. Bupropion is also found in the smoking cessation agent Zyban.

Do Antihistamines Lead To Weight Gain?

It is well known that antihistamines can lead to weight gain. In fact, one antihistamine -- cyproheptadine -- is used specifically for this purpose. However, most people do not want added weight with use of an antihistamine.

Antihistamines, such as:

block histamine receptors. These drugs can be bought without prescriptions and have been associated with weight gain. Antihistamine activity can boost appetite, as noted with several other drugs that cause weight gain, like some antidepressants.

Studies have shown that some H1 antihistamines may increase weight, body mass index, waist circumference, and insulin levels. For many patients, the allergy benefit with antihistamines outweighs any slight weight gain risk.

Do Antipsychotics Cause Weight Gain?

Many antipsychotics are known for weight gain. Antipsychotic medications are often used for bipolar disorder and schizophrenia, and patients can gain from 7 to 10 percent of their body weight.

The atypical antipsychotics

  • olanzapine (Zyprexa)
  • risperidone (Risperdal)
  • clozapine (Clozaril)

have all been linked to significant weight gain. These drugs may block histamine activity and serotonin, as well, which may contribute to the mechanism of weight gain.

Can Antipsychotics Affect Weight-Related Risks?

Some antipsychotics may impair glucose (sugar) control and lead to insulin resistance, impaired glucose tolerance and a higher risk for type 2 diabetes.

However, these drugs are often absolutely needed for treatment of conditions like bipolar disorder or schizophrenia, and patients must speak with their physician before stopping or changing treatment.

Ziprasidone (Geodon) and aripiprazole (Abilify) are more weight neutral antipsychotics, but may still increase blood sugar.

Can Blood Pressure Medications Cause Weight Gain?

Beta-blockers are a frequently used class of drug for blood pressure, and they are cost effective, too - but many beta-blockers are linked with weight gain. Common examples of this class that may expand the waist include:

  • metoprolol
  • atenolol
  • propranolol

Many of the older beta-blocker drugs may slow down activity in general, which may be responsible for some of the weight gain. Patients may be tired, have lack of energy, and feel fatigued, which may affect their ability to stay active and exercise. This can lower the number of calories burned each day.

Can Corticosteroids Increase Appetite?

Oral corticosteroids (glucocorticoids) are drugs such as:

  • prednisone
  • methylprednisolone
  • hydrocortisone

Corticosteroids are used for severe asthma, acute allergies or inflammatory disorders such as arthritis. These drugs can boost the metabolic rate and the appetite, too. High doses and long-term use of these agents may carry a significant risk of weight gain.

Local injectable corticosteroids (for example, used for knee pain) and inhaled corticosteroids used for asthma are not associated with weight gain.

Catch 22: Certain Diabetes Drugs Result in Added Pounds

Putting on weight is the last thing someone with type 2 diabetes should do; it can worsen their condition.

However, the type 2 diabetes drugs

  • glyburide (DiaBeta)
  • glipizide (Glucotrol)

both from an older diabetes drug class, can lead to weight gain. These agents may increase insulin production, which can lower blood sugar and increase appetite. Injectable insulin can also lead to weight gain.

Other drugs used in the treatment of type 2 diabetes, such as pioglitazone (Actos) and rosiglitazone (Avandia), may lead to weight gain and fluid (water) retention.

Which Diabetes Drugs Lead to Less Weight Gain?

Metformin (Glucophage) and sitagliptin (Januvia), type 2 diabetes drugs, may either not affect weight or be associated with weight loss.

Exenatide (Byetta), liraglutide (Victoza), and dulaglutide (Trulicity) are glucagon-like peptide-1 (GLP-1) receptor agonists that slow digestion in the stomach, but can lead to nausea and vomiting. These drugs have been shown to lead to modest weight loss, even in patients without diabetes, but these brands are not approved for that use.

Saxenda is the brand name of liraglutide approved to help with weight loss, along with diet and exercise, but is not used in treating type 1 or type 2 diabetes. Be sure you do not use Saxenda and Victoza together.

Seizure Drugs and Mood Stabilizers Can Add Pounds

Valproic acid (Depakote, Depakene) is used to treat epilepsy (seizures) and bipolar disorder, and is also used for migraine prevention. Valproic acid appears to boost appetite and may result in a 10 pound or more weight gain. Lithium (Lithobid) is also used for mood disorders and is linked with weight gain.

These are important medications for serious conditions; patients should discuss weight gain with their doctor before stopping or changing any medications.

What Should I Do If I Think My Medication Is Causing Weight Gain?

If you gain weight after starting a medication, talk to your doctor about the benefits and risks of using the drug. It may be that the drug is not the cause of the weight gain, but your diet and exercise may need boosting. Your doctor can give you advice on how to control the weight, including exercise and diet tips.

If a change in your medication is needed, there may be another drug your doctor can prescribe that will work just as well, but not increase your weight.

Finished: Can Prescription Drugs Lead to Weight Gain?

FDA-Approved Weight Loss Drugs: Can They Help You?

Are the latest weight loss pills the cure-all for the obesity epidemic? Here, review what could help combat the expanding waistline of the nation.



  • Fields T. Hospital for Special Surgery. Steroid Side Effects: How to Reduce Corticosteroid Side Effects. 4/11/2017. Accessed August 22, 2017 at
  • Antihistamines and weight gain. Ask the Expert. American Academy of Allergy, Asthma & Immunology. Accessed August 22, 2017 at
  • Ratliff J, Barber J, Palmese L, et al. Association of prescription H1 antihistamine use with obesity: Results from the National Health and Nutrition Examination Survey. Obesity (Silver Spring, Md). 2010;18(12):2398-2400. doi:10.1038/oby.2010.176. Accessed August 22, 2017 at
  • Weight Control Information Network (NIDDK) - Overweight and Obesity Statistics. 11/2012. Accessed August 22, 2017 at.
  • Prescription Meds Can Put on Unwanted Pounds. Accessed August 22, 2017 at
  • Cheskin L, et al. Prescription medications: a modifiable contributor to obesity. South Med J. 1999;92:898-904. Accessed August 22, 2017 at