Is Weight Gain Caused by Medicine?

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Common Medications That Can Cause Weight Gain

It can be a frustrating and difficult process for women taking an essential medication that causes weight gain. Unfortunately, weight gain is a side effect of many medications, and other health risks often accompany this gain or are a direct result of medication-induced weight gain. Fortunately, even when diet and exercise don’t seem to make enough difference, there are things you can do to minimize this side effect of medications.

Common Medications That Can Cause Weight Gain

There are quite a few medications, both prescription and over the counter, that have a tendency to cause weight gain. This side effect is typically listed in the insert that comes with prescription medications, but it’s not commonly indicated on over-the-counter medication packaging. Below are the main categories of medicines that are known to cause weight gain.

Diabetes Medications

Diabetes Medications

Of course, not all diabetes medications cause weight gain, but there are a significant handful that do. Because these are medications that promote the absorption of blood sugar (glucose) into other cells in the body, when the cells absorb the extra glucose, it can be stored as fat. Therefore, most patients gain between five and ten pounds when they start taking certain diabetes medications.

These include the following prescription medications for diabetes:

  • Insulin
  • Glitazones such as pioglitazone (Actos)
  • Glinides such as repaglinide
  • Sulfonylureas such as glipizide

Antidepressants or Mood Stabilizers

Some mood stabilizers and antidepressants can cause weight gain in patients who take them. Why these medications cause weight gain is unknown, and it’s hard to say the amount of weight gain patients can expect when they start taking these medications because the span varies so significantly from patient to patient.

For example, lithium has been known to cause weight gain averaging between two and 22 pounds, and amitriptyline has been known to cause anywhere from one to 16 pounds of weight gain. The only consensus is that these medications cause significant weight gain in some patients but not in others.

Mood stabilizers known to cause weight gain include:

  • Lithium medications like Lithobid
  • Some selective serotonin reuptake inhibitors (SSRIs) like Paxil
  • Mirtazapine (Remeron)
  • Tricyclic antidepressants (TCAs) such as amitriptyline and nortriptyline (Pamelor)
Antidepressants or Mood Stabilizers


If someone is diagnosed with bipolar disorder, depression, or schizophrenia, they may be prescribed antipsychotic medication. Some of these medications are known to cause weight gain and can affect other components of metabolism, as well. In part, this weight gain can be attributed to the fact that these medications simply make patients hungrier than normal. They can also raise cholesterol and prevent the regular and efficient breakdown of glucose in the body. Consequently, certain antipsychotic medications can lead to other health risks, such as Type 2 diabetes.

Antipsychotic medications that may cause weight gain include:

  • Risperidone (Risperdal)
  • Quetiapine (Seroquel)
  • Olanzapine (Zyprexa)
  • Clozapine (Clozaril)


Anticonvulsant medications are used to treat seizures and may be used off-label to treat bipolar disorder, nerve pain, and migraines. Some anticonvulsants can cause weight gain, though it’s not clear why they do. It may be a result of an increased appetite many patients experience when taking these medications.

Not all anticonvulsants cause weight gain, however. Lamictal typically has no weight gain effect, and others, such as topiramate (Topamax), may actually contribute to weight loss.

Still, the following anticonvulsants are known to cause weight gain:

  • Valproate (Depakene, Depakote)
  • Carbamazepine (Tegretol, Equetro)
  • Pregabalin (Lyrica)
  • Gabapentin (Neurontin)



Some antihistamines used to treat allergic reactions and allergy symptoms are well-known to cause drowsiness, but many patients don’t realize they may also cause weight gain. This may be because they make some people hungrier, and the drowsiness may also contribute to lack of activity and, thus, lead to weight gain.

More research is needed to pinpoint which ones have a higher risk of causing weight gain, but some antihistamines that might cause weight gain are listed below:

  • Diphenhydramine (Benadryl)
  • Hydroxyzine (Vistaril)
  • Cyproheptadine

Beta Blockers

It’s important to note that not all beta blockers cause weight gain. However, some beta blockers that are prescribed for patients who have heart failure or abnormal heart rhythms have been known to cause weight gain. This may be because beta blockers can slow metabolism and make it harder to stay active and exercise.

Weight gain caused by beta blockers usually occurs during the first couple of months of treatment and tapers off once the body adapts to the medicine. Weight gain from beta blockers averages two to three pounds, though some could gain more than others. Patients taking metoprolol or propranolol may gain up to five pounds, while patients taking atenolol have been known to gain as much as 7.5 pounds.

Beta blockers that frequently cause weight gain include:

  • Propranolol
  • Metoprolol (Lopressor, Toprol XL)
  • Atenolol (Tenormin)


Corticosteroids like prednisone are prescribed to reduce inflammation in the body. However, one of the most significant long-term effects of many steroids is weight gain. This weight gain is a result of these medications mimicking a hormone in the body called cortisol, which is believed to stimulate appetite and change the way the body processes sugar and fat. Steroids can also build up over time in the body, also contributing to weight gain.

Corticosteroids like prednisone are prescribed to reduce inflammation in the body. However, one of the most significant long-term effects of many steroids is weight gain. This weight gain is a result of these medications mimicking a hormone in the body called cortisol, which is believed to stimulate appetite and change the way the body processes sugar and fat. Steroids can also build up over time in the body, also contributing to weight gain.

Birth Control

Birth Control

It is not likely that most hormonal birth control causes weight gain, but weight gain can occur with birth control due to water retention and bloating when women first begin a prescription. This extra water weight typically goes away as the body adjusts to the medication.

One exception to this is the birth control shot, Depo-Provera (medroxyprogesterone). This shot can cause up to 20 pounds or more of weight gain over the first 18 months after getting the shot. According to the label, 38% of clinical trials gained at least 10 pounds within the first two years.

Suggested Reading: Saliva Hormone Testing FAQs

Other Medications

Any medicine that causes you to feel tired or drowsy can make you less active when taken regularly. When a medicine depletes energy and is taken during the day, it can lead to a more sedentary lifestyle for some people. When coupled with poor eating habits, these medications can cause slight weight gain. Examples of these types of medications are melatonin, Ambien, or other sleep-inducing medications and supplements.

Weight Gain and Your Metabolism

If switching your medication to another alternative that does not induce weight gain is not an option, there are other things you can do that may help provide balance. Lifestyle changes such as regular exercise and eating a healthier diet can help you maintain a healthy weight. Here’s how.

Metabolism is the body’s process in which food and drink are converted into energy. This complex chemical reaction is how the body gets energy for everyday bodily functions such as breathing and blood circulation. A person’s metabolic rate, or metabolism, is the rate at which the body burns calories while in motion or rest, and is largely determined by genetics, sex, body composition, and age. While these are all factors that cannot be controlled or changed, there are two contributing factors to metabolism that can be controlled to optimize metabolism. These are physical activity and thermogenesis, or the digestion of food.

The number of calories you burn while exercising or during regular daily activities depends mostly on the activity itself. Even daily routines burn calories, and when you engage in intense workouts, you burn more calories. The body needs calories to digest food. The digestive process begins with eating, then absorbing, and finally storing proteins from the food that is digested. This process accounts for many of the calories that are burned on a daily basis.

Ways to Boost Metabolism

While your metabolism is mostly dictated by things you can’t control, including age and sex, there are a few things you can do to boost your metabolism. Boosting metabolism is a good way to initiate weight loss.

Interval Training

One way you can do so is through interval training. This type of workout spaces out high-intensity activity with periods of rest. Exercising in this pattern burns more calories while active, and the body continues to burn calories after exercise.

Strength Training

Strength Training

Another way to boost metabolism is to incorporate strength training into your exercise routine. This adds more muscle mass to the body and increases your metabolic rate, which allows the body to burn more calories, even when at rest.

Diet Changes

A diet heavy in metabolic-friendly foods is a diet rich in fiber and protein. These foods make the body feel fuller longer and boost metabolism. Swapping out empty calories, such as fast food or junk food for meals or snacks that include berries, legumes, or seafood will enhance one’s metabolic rate.

Getting More Sleep

Practicing healthy sleeping patterns is another way to boost metabolism. Individuals looking to boost their metabolism while sleeping should avoid large meals before bedtime, avoid using electronic devices in bed, and keep the bedroom cool to promote a good night’s sleep. A well-rested body will optimize metabolic rate, and this can reduce stress and prevent an individual from making poor dietary choices when awake.

Custom Medication for Weight Loss

When it comes to weight loss, there are different approaches to consider. One effective way to start is by making dietary changes or incorporating exercise routines that increase calorie burn and facilitate fat elimination. While many individuals have had positive outcomes with these exercise routines, it’s important to note that weight loss is not a one-size-fits-all journey.

Custom Medication for Weight Loss

Factors such as illnesses, genetic predispositions, and age may introduce complexities that challenge traditional diet and exercise approaches. However, by understanding these nuances and exploring personalized strategies, individuals can navigate the path to successful weight loss. For effective weight management, personalized care is crucial, and we are here to assist you.

Whether you are in need of a supplement or seeking a solution to integrate weight loss with treatment for a pre-existing medical condition, our team of compounding pharmacists is dedicated to formulating a distinctive prescription tailored to your individual diagnosis and requirements. You can rely on our expertise and commitment to providing comprehensive and personalized solutions for your health and well-being.

Vitamins, Supplements, and Custom Medication for Weight Loss Management

Many vitamins and supplements can help you manage your weight and support weight loss. In addition to weight loss products offered throughout our store, we offer custom medication for weight loss management. You need personalized care for effective weight management, and Compounding Pharmacy of America can help. Whether you are searching for a supplement or a way to combine weight loss and treatment for an existing medical condition, our compounding pharmacists can formulate a unique prescription for you based on your unique diagnosis and needs.

About Matt Poteet, Pharm.D.

Chief Operating Officer, The Compounding Pharmacy of America Matthew Poteet, Pharm.D. graduated with Honors from Lee University with a Bachelors of Science in Biological Science. After his undergraduate training, he completed the Doctor of Pharmacy program at Mercer University Southern School of Pharmacy, graduating in 2004. Dr. Poteet has spent much of his pharmacy career on staff at two of the most prestigious academic teaching hospitals in the Southeast; Emory University in Atlanta and Vanderbilt University Medical Center in Nashville. At these institutions he received extensive experience and training in sterile products compounding. He returned home to East Tennessee in 2010, where he has held the position of Pharmacy Director at two sterile products pharmacies in Knoxville. Matthew lives in Knoxville with his wife, Chris. Dr. Poteet is Tennessee’s first Board Certified Anti-Aging Pharmacist by the American Academy of Anti-Aging Medicine. Read More About Matthew Poteet, PharmD