Pristiq Weight Gain or Weight Loss: Everything You Need to Know

Weight Changes While Taking Pristiq

Pristiq may cause weight-related side effects. If you have lost your appetite from depression, antidepressants in general can cause weight gain as you start to feel better and regain your appetite. However, Pristiq on average has not been found to cause significant weight gain.⁴ This is due to its action on norepinephrine. Long-term, one-third of patients have 7% or more increase in weight.

In contrast, you may lose weight as you start to feel better, and feel less of a need to emotionally eat. Also, you may have nausea for the first couple of weeks and lose weight during this process. In addition, due to its action on norepinephrine, about 5% of patients taking Pristiq will have appetite loss, which can lead to weight loss. However, loss of appetite also typically resolves after a few weeks.³

How Can Pristiq Cause Weight Gain?

Pristiq may cause weight gain in a few possible ways. The mechanism of feeling better from antidepressants in general may help your appetite, causing weight gain. In addition, sleep and energy changes may occur, which can have an impact on your weight.

Potential causes for Pristiq weight gain may include:

Appetite Increase

Taking antidepressants can help you regain your appetite as you start to feel better. Weight changes are typically small, if any. The change in weight is greater when used long-term and with larger doses. However, you can combat this with weight loss strategies. Also, taking no more than 50 mg may help, as greater doses have not been shown to add any additional benefits.

Side Effects

A common side effect is insomnia, which can impact your sleep and change your energy levels. Lack of quality sleep and lower energy levels can contribute to weight gain due to lower activity levels.

How Can Pristiq Cause Weight Loss?

For some, Pristiq may cause weight loss. Since Pristiq acts on norepinephrine levels, a stress hormone, your body is signaled to go into “fight or flight” mode instead of “rest or digest” mode. This decreases signals to the brain for hunger, lowering your appetite.

Potential causes for Pristiq weight loss are:

Digestive Side Effects

Like other antidepressants, Pristiq can have some digestive side effects that may result in weight loss, such as nausea, vomiting, and diarrhea. These can be signs of serotonin syndrome. If you are having several bouts of vomiting or diarrhea, talk to your doctor or pharmacist immediately.

Increased Energy

As you continue to take Pristiq, your mood will improve and so may your energy. The increase in energy can help you become more active, burning more calories. In addition, Pristiq acts on norepinephrine, which helps to initiate energy mobility. Norepinephrine can increase your “fight or flight” mode, lowering your body’s perceived need for digestion.

Factors That Can Influence Weight Changes While Taking Pristiq

Factors that can influence your weight while taking Pristiq include dosage, age, gender, genetics, stress levels, quality of sleep, medical conditions, and physical activity. In general, Asians typically have lower body mass indexes (BMIs), which is a measure of body fat based on height and weight. African Americans, Pacific Islanders, and Native Americans genetically have higher BMIs.

Factors that can influence weight changes are:

Dosage

One side effect of Pristiq is weight loss, and the higher the dosage you are on, the more likely you are to experience side effects. To prevent this, your prescriber may keep you within the 25-50 mg range, as higher doses have not been shown to add benefit.

Individual Factors

Age, gender, genetics, stress levels, and quality of sleep can play a role in weight changes. As we get older, it is harder for our bodies to keep up with metabolism. Also, some populations are more prone to gaining or losing weight easier. In addition, medical conditions like diabetes and obesity, can make it harder to lose weight. Your level of physical activity can also impact weight.

Do All Antidepressants Cause Weight Changes?

In general, all antidepressants can cause nausea, which may also lead to weight loss. In contrast, treating depression can cause your appetite to return and cause weight gain. Some antidepressants are more stimulating, like Prozac, and are more likely to cause weight loss. Weight-neutral antidepressants include other SSRIs and SNRIs. In contrast, Elavil and Remeron are antidepressants that are the most likely to cause weight gain.

Coping With Weight Changes From Taking Pristiq

Managing your weight with depression can be difficult, even without side effects. If you can use several strategies, you may have an easier time managing it. Some strategies include adjusting your dose, switching antidepressants, eating more mindfully, getting exercise, and working with a dietician. Weight-management strategies can also help manage depression and anxiety by helping you feel accomplished, improving your self-confidence, and enhancing your physical health.

Here are 5 ways to manage weight changes while taking Pristiq (desvenlafaxine):

• Adjusting doses: Adjusting your dose may help. For example, Pristiq is easily cut in half, so you may want try a dose that is in between a past dose and your current dose.
• Switching antidepressants: Switching antidepressants may help, since some are less likely to cause weight changes or nausea. Talk to your prescriber about your options.
• Eating healthy/eating more mindfully: If you are managing weight loss, eating smaller, more frequent meals may help keep your appetite going and your calorie intake up. If you are having weight gain issues, eating slower and while not distracted can help you take in your food’s taste more and make you feel more full.
• Getting regular exercise – Exercise is great for increasing your appetite while helping you lose weight, as are the mental health benefits of exercise. It can even be easily fit into your routine, such as a 10-minute walk on your lunch break with a coworker.
• Working with a dietician to manage caloric intake/nutrition – Dieticians can help you create a healthy meal plan that incorporates your favorite foods.

Other Side Effects of Taking Pristiq

For some people, Pristiq side effects may include nausea, dizziness, insomnia, decreased appetite, constipation, dry mouth, sweating, and sexual issues.² It can also cause fatigue, somnolence, and anxiety. Less common side effects include abnormal dreams, jitteriness, burning or prickling sensations, and tremor. Side effects that can be serious that you should seek medical attention for include abnormal vision or pupil dilation, high blood pressure, and continuous vomiting or diarrhea.

Questions to Ask Your Healthcare Provider

You may want to consider taking Pristiq if you have tried all SSRIs without success or had intolerable side effects. The next step is to try any of the SNRIs, so potentially Pristiq. If you are considering trying Pristiq, you may want to ask your doctor, psychiatrist, and therapist if it is right for you. They can help you consider its side effects and your medical history.

Questions to ask your care team when considering the side effects of Pristiq may include:

• How can I tell if it’s the medication rather than my depression causing the weight gain/weight loss?
• How long will weight gain/weight loss side effects in Pristiq last?
• Am I at risk for increased weight gain if I am already taking other anxiety /depression medications?
• Will a previous history of weight gain/weight loss make me more susceptible?
• What is the best dosage to ensure less weight gain/weight loss?
• Are there drugs I am taking that could have increased effects on weight gain/weight loss?
• When should I reach out to you if I am experiencing too much weight gain/weight loss?
• Are there other medications that will have less weight gain/loss?
• What should my goal weight and BMI be?
• What is the recommended amount of exercise per week?
• What are some easy ways I can fit exercise into my routine?
• When will the weight effects of Pristiq wear off?
• What is a healthy amount of weight to lose per week?
• When should I consider seeing a dietician or personal trainer?
• What are some ways I can have my family help support my weight gain or loss?
• What is the best time of day to exercise?