Paxil Weight Gain And Loss: Causes And Prevention

Last Updated: April 16, 2024

Roger Weiss Authored by Roger Weiss, MD
0 sources cited

Patients getting treatment for depression are often prescribed with antidepressants such as SSRIs or selective serotonin reuptake inhibitors. Paroxetine, one of the medications belonging to this drug class, has been proven effective to treat depression since 1992. However, more often than not, users are faced with another health issue caused by the active link between Paxil, one of the drug’s brand names, and weight gain. Based on the study of physicians from the United States, Paroxetine users may gain an additional mass by up to 3.6%. Nonetheless, this mass buildup is affected by many factors.

Does Paxil Cause Weight Gain?

While a lot of people find that Paroxetine works effectively against anxiety, depression, OCD, phobia, and panic disorder, like many other drugs, there are Paxil adverse effects. So, for those who might be wondering: does Paxil cause weight gain? The answer is that this potent drug is more likely to cause mass buildup as compared to other SSRIs, especially during long-term treatment, approximately six months or more. As claimed by researchers from Boston, Paroxetine has been associated with more mass buildup compared to other antidepressants and SSRIs like Sertraline or Fluoxetine. Furthermore, in the same study, it was reported that Sertraline and Fluoxetine may only provide an increased 6.8% and 4.2% of weight gain respectively while Paroxetine can add up to 7% on the initial body weight of the patient.

Why Does Paroxetine Cause Weight Gain?

There are several reasons why the Paxil side effects weight gain occurs. As reported by researchers from Australia, the main reason why patients gain some pounds on this antidepressant is because of their unhealthy lifestyles such as poor diet, inadequate physical activities, and smoking habits. In this section, information about the other causes of Paxil weight gain will be provided.

Serotonin Deficiency

The Paxil side effects weight can be attributed to the drug’s effects on hormones, including serotonin, which helps control and regulate appetite. Take note that Serotonin deficiency can cause significant mass buildup and this deficiency is caused by disturbed serotonergic signaling. Consistent with the study of medical doctors from the Netherlands, obesity or mass buildup is associated with disturbed serotonergic signaling.

Recovery From Depression

With depression, people usually have a low body mass because they’ve lost interest in food and pleasure. But, as stated by the FDA, as soon as antidepressants like Paroxetine start to kick in, their metabolism will decrease, they will feel better, and start getting a boost on appetite, which makes them eat more than usual. Moreover, from the FDA, this mass buildup may be considered frequent.

A person's legs on a scale.

Increased Fat Storage

The use of a psychotropic drug like Paroxetine may also affect the way the body processes fat. As claimed by health professionals from Washington, when taken for an extended period, physiological changes may ensue, leading to more fat storage and abnormal fat deposition. In addition to this, taking Paxil and alcohol together, aside from causing health dangers, may also promote increased fat storage.


Administration of Paroxetine can significantly modulate human taste perception. It increases both sweet and bitter sensitivity. This means that patients taking this drug are more prone to seek out unhealthy food products that contain high amounts of sugar and this may lead to more carbohydrate cravings. Though there has been a clear association between carbohydrates and the secretion of serotonin, less is known about how and which quantity of Paroxetine plays a role. As per the study of scientists from New York, low-dose Paroxetine (7.5 mg) will not alter the cravings of the patients and will not cause an increase in body weight.

Drug Combinations

Certain medications can amplify Paroxetine weight gain. Risperidone, for example, when used with Paroxetine can inhibit the CYP4502D6 enzyme. This combination has been found to increase a patient’s body mass by approximately 30 pounds within five months of treatment. Because of this, patients taking this antidepressant are highly advised to tell their medical doctor about the other medications they take to avoid interactions that can cause dangers to their health.

Side Effects

The side effects of Paroxetine are similar to other SSRIs, but it tends to be more sedating. As reported by medical researchers from the USA, this antidepressant drug is associated with apathy. It makes people feel fatigued, sleepy, and not willing to be social and active. Aside from having a decrease in motivation, a sedentary lifestyle goes with it. An inactive lifestyle can increase one’s risk of obesity. Furthermore, take note that Paroxetine half-life determines how long the side effects may last. So, as the concentration of Paroxetine decreases, the severity of side effects decreases as well.

Withdrawal Symptoms

Patients who have stopped taking Paroxetine abruptly may also experience Paroxetine withdrawal symptoms. The main signs include dizziness, vertigo, headache, nausea, flu-like symptoms, insomnia, and more. This will leave the patient feeling lazy to move as well, and there’s a big possibility of giving in to stress eating.

How Much Weight Do People Gain on Paxil?

Experts and pharmaceutical companies are advertising that medications like Paroxetine are weight neutral, but there is evidence showing otherwise. Studies have found an association between Paxil and weight gain. Paroxetine can increase body mass when used long-term. A patient can gain as much as 24 pounds within 6-12 months of treatment with Paroxetine as compared to only 10 pounds with other SSRIs.

Factors Affecting Paxil Weight Gain

From the report of researchers from Australia, being exposed to antidepressants can increase the risk of mass buildup, and when talking about Paroxetine, aside from knowing the reasons why Paxil weight gain occurs, it is also necessary to learn the factors that may add to obesifying effects of the drug.

Some of These Factors Include:

  • Other Medications– As mentioned earlier, the use of combination drugs may contribute to Paxil weight gain, especially if they are psychiatric.
  • Dosage– The dosage will also reflect on the drug’s effect. A doctor usually prescribes Paroxetine 20 mg for patients with generalized anxiety, but if it is raised, there’s a higher probability of the antidepressant drug increasing body mass. Also, imbalances in the neurotransmitter levels and the nervous system are more likely caused by higher drug doses. Homeostatic processes are affected, including metabolism, which can result in a mass buildup.
  • Duration of Treatment– Paxil weight loss or gain is possible depending on the length of treatment. The risk of growing bigger increases as treatment prolongs. As time passes, patients are more likely to need an increase in their dosage, causing further Paxil weight gain.
  • Genetics– Some gain some pounds quickly while on this drug. The risk of obesity with regards to Paxil and weight gain increases by 25% if one or both of the parents are obese.
  • Unhealthy Lifestyle– In most cases, a sudden shift to an unhealthy lifestyle along with stress, influences the occurrence of mass buildup.

Although there are many uses of Paroxetine, and Paxil side effects weight fluctuations might be frequent, it is highly advised for all patients to share the side effects they experience while using the medication.

A doctor holds an apple in her hand.

Paxil Weight Loss: Is There Any Relation

Take note that Paxil and weight gain may not be experienced by everyone. Weight loss is also an undesirable result of Paroxetine treatment, especially in the early stages. Some studies revealed a significant Paxil weight loss, an average of 1 pound, on patients in controlled trials compared to smaller weight changes in those who had a placebo.

Losing some pounds on Paroxetine can be best explained by the drug’s ability to make depressed people calmer and less anxious. They get better sleep and feel more relaxed during treatment. This improved mood usually helps bring back self-confidence and interest in doing physical activities and socializing with others. It also enhances mental health, allowing patients to make better decisions about food choices.

According to a clinical review, small weight losses can be experienced when SSRI drugs like Paroxetine are taken in short-term treatment. This means that it is only possible for patients to experience Paroxetine weight gain when they have been using Paroxetine for a long period.

How to Manage Paxil Weight Fluctuations

Even though Paroxetine is effective for depression, it can promote unwanted side effects such as Paroxetine weight gain or weight loss. For patients who do not desire this side effect, help must be given.

So, for Patients Looking for Some Tips on How To Lose Some Pounds While on This Drug, Take a Look at the Information Below:

  • Before the use of Paroxetine for anxiety, get weighed. Be sure to record it for reference during follow-up visits.
  • Be sure to know the difference between having an appetite and hunger. Paroxetine can increase one’s appetite, making a patient crave more food without feeling hungry.
  • A serotonin diet is a strategy that seems to work against the obesifying effects of Brisdelle. Serotonin is made after carb intake, except fructose. Sugary food, when digested, gives off tryptophan, which is used by the brain to produce serotonin. Patients are advised to take approximately 30 grams of sweet or starchy foods for breakfast.
  • Do not use or mix carbohydrates and protein, or no serotonin will be produced. Protein foods interfere with the ability of tryptophan to reach the brain.
  • Intervention is also the key. Patients with metabolic risks should see a doctor. A weight loss agent may be prescribed and monitored closely by a medical professional for weight gain. In some cases, a doctor may ask patients to look and use safer Paxil alternatives. It is best to make drug comparisons like at Paxil vs Xanax.

Take note that weight control is not the biggest problem with Paroxetine. This medication is habit-forming, and help may be required. A patient seeking help may consider getting treatment for substance abuse. The person in need of therapy will be enrolled in one of the numerous drug recovery centers. Keep in mind that the professionals in these institutions respect the patient’s privacy.

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Page Sources

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Published on: May 23rd, 2019

Updated on: April 16th, 2024


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