Does Wegovy make you tired?

Your weight is down, your appetite is down, and suddenly, so is your energy. If you’re wondering, “does Wegovy make you tired?” you’re not alone. Fatigue is actually one of the more commonly reported side effects of Wegovy (semaglutide)—after, of course, gastrointestinal ones, like nausea and vomiting. And while not everyone will experience tiredness while taking the injectable medicine, it’s quite possible you might feel as if your energy’s taken a dip sometime during your treatment. 

But why can Wegovy cause fatigue? And how can you bounce back? Ahead, we answer those questions and break down what you need to know about feeling tired on Wegovy. 

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Yes, Wegovy can make you tired. In fact, fatigue listed as a potential adverse side effect on the prescribing information (PI) for the drug, and research backs this up. 

• In clinical trials, 11% of participants taking 2.4 mg of Wegovy reported experiencing fatigue after 68 weeks (about a year and a half) of treatment. This was more than double the amount in the placebo group. 

• Another clinical trial looked at adults with overweight or obesity who took 2.4 mg of semaglutide for 68 weeks and found that 12.8% of participants reported fatigue at some time during their treatment. 

• A retrospective study evaluated the real-world outcomes among people with overweight or obesity who took 1.7 mg or 2.4 mg of semaglutide for up to six months. Nausea was the most commonly reported effect, affecting 36% of participants, while 8% reported diarrhea and 6% fatigue. 

While the specific percentages varied, the number of Wegovy-taking people who reported fatigue in the research was consistently less than those who reported gastrointestinal symptoms. Take, for example, the first clinical trial mentioned above. In this study, only 11% of participants experienced fatigue. Meanwhile, 44%  reported nausea, 30% diarrhea, and 24% constipation—fatigue was the seventh most common side effect. 

"Tiredness may be the kind of side effect that's less noticed compared to an effect like nausea or constipation. That's because you might attribute it to other causes like a busy schedule. However, it's helpful to know that it could be related to semaglutide," says Allison Rhodes, MD, a dual-board certified physician in internal medicine and obesity medicine at The Ohio State University Wexner Medical Center.

There are various reasons why Wegovy can cause fatigue, including reduced caloric intake, metabolic changes, sleep challenges, low blood sugar, increased physical activity, and dehydration. While each person’s experience may differ, all of the potential causes can be tied back to the way the drug works. 

Wegovy is a glucagon-like peptide-1 (GLP-1) receptor agonist, a type of medication that mimics the GLP-1 hormone naturally found in the gut. It binds to GLP-1 receptors to increase insulin production, inhibit glucagon production, and slow gastric emptying (the rate at which food moves through your stomach). In these ways, Wegovy is able to stabilize blood sugar, prolong feelings of fullness, and reduce appetite—the latter of which the drug also does by signaling to the brain that you’re full. As a result, Wegovy can cause you to eat less, take in fewer calories, and sometimes feel more tired as your body adjusts to the drop in energy intake. 

Got all that? Good! Now, let’s take a closer look at the potential reasons for Wegovy fatigue.

Calorie reduction

Like other GLP-1 receptor agonists, Wegovy can have a profound effect on appetite, Dr. Rhodes says. As mentioned above, these medications slow gastric emptying and decrease hunger cues in the brain, which can lead you to feel fuller sooner and for longer and eat less overall. This can be an effective way to slim down, largely because you end up taking in fewer calories. But for the same reason, you might feel depleted and tired—after all, calories are your body’s energy source.  

"When you eat fewer calories, it takes your body time to adjust," Dr. Rhodes says. "That's true whether you're on Wegovy, another semaglutide medication, or you're just in a calorie deficit in general."

Sleep challenges

Common side effects of Wegovy like gastrointestinal issues (e.g. nausea, stomach pain, diarrhea), headaches, and low blood sugar can sabotage sleep quality, Dr. Rhodes says. This can create a cycle in which poor sleep worsens symptoms, and those symptoms, in turn, make it harder to sleep. 

Think of it this way: If your stomach is hurting or if you’re running to the bathroom too often, your body likely isn’t going to get the rest it needs. As sleep quality is affected, the more likely you are to experience daytime sleepiness and general fatigue, Dr. Rhodes explains.  

Fortunately, as your body adjusts to the weight loss medication, these effects may be minimized or alleviated, Dr. Rhodes suggests. When that happens, your sleep may improve, which means your energy level may bounce back, too.

Low blood sugar

Semaglutide, the active ingredient in Wegovy, is known for its impressive ability to control blood glucose (sugar) levels. While Wegovy isn’t FDA-approved for this specific purpose, it can still influence how the body regulates blood sugar. In some cases, this can lead to mild hypoglycemia (low blood sugar), especially in people with type 2 diabetes or who are taking other glucose-lowering medications (e.g. insulin). Your healthcare provider may even adjust dosages of diabetes medication for people who  are on Wegovy to help avoid instances of low blood sugar. And guess what low blood sugar can cause? If you guessed fatigue, you’re correct. 

Metabolic changes

"As you experience weight loss, your body might undergo shifts in how your metabolism operates," Dr. Rhodes says. 

When you lose weight, your body might slow down your metabolism (the rate at which it burns calories for energy) to help maintain the new, lower weight. But because you’re now burning fewer calories, you might also have less energy available. This can lead you to feel more fatigued or tired—at least until your body has adjusted to the medication, Dr. Rhodes explains.  

Increased physical activity

One of the keys to successful weight loss? Regular exercise. Not only that, but Wegovy is actually indicated in combination with a reduced-calorie diet and increased physical activity. 

Point being: If you’re taking Wegovy as directed, you’re likely spending more time breaking a sweat. While moving your body can be beneficial for your overall health and weight loss goals, ramping up your workout routine can contribute to tiredness, according to Dr. Rhodes. This can be especially true if you’re new to working out. 

Such fatigue on Wegovy can feel even more intense if you’re not adequately refueling with the right foods post-workout—a task that can feel particularly challenging given the drug’s appetite-suppressing effects. If you’re burning more calories through exercise but not eating enough to fuel your workouts or support muscle recovery, your body may struggle to keep up. 

In fact, research shows that calorie deficits and low protein intake during weight loss can contribute to reduced energy and muscle weakness. Add into the mix dehydration and you’ve got yourself a recipe for exhaustion. Speaking of which…

Dehydration

The more you move your body, the more you need to hydrate. But increased physical activity isn’t the only potential cause of dehydration while taking Wegovy. Gastrointestinal side effects, such as diarrhea and vomiting, can also be to blame, as they can cause you to lose more fluids than your body needs. Plus, research on dulaglutide (another GLP-1) suggests that the GLP-1 hormone itself can suppress your ability to sense thirst and the amount of fluid you drink. 

No matter the specific cause, however, dehydration can lead to fatigue. It’s also been shown to cause other lethargy-related symptoms, such as feeling less alert and worsened concentration. 

Because every person’s experience is different, there’s no set time for how long Wegovy fatigue lasts. While the medication may make some people tired a few hours after their weekly injection, it can leave others feeling fatigued for weeks. In general, however, Wegovy side effects tend to go away over time as your body adjusts to the medication. And for some people, fatigue can be relieved with some lifestyle changes—but we’ll get to those in a minute. 

First, it’s important to note that clinical trials suggest that side effects tend to be dose-dependent. This means that they typically get worse as you increase your dose of Wegovy, and the higher the amount prescribed, the more likely you may be to feel tired. But dosage isn’t the only factor that can affect your chances of experiencing fatigue and its duration. 

"Side effects for Wegovy, similar to other GLP-1 medications, can be influenced by lifestyle habits," Dr. Rhodes says. "For instance, if you're not sleeping enough, side effects like fatigue or even nausea could happen more often."

For the same reason, however, certain lifestyle changes can actually alleviate fatigue on Wegovy. 

Although Wegovy-related fatigue might lessen over time on its own, there are simple lifestyle strategies that may help shorten that timeframe. Keep in mind, though, that it’s always a good idea to consult your healthcare provider if you’re feeling tired or dealing with any other side effects while taking Wegovy. 

"The earlier you can address issues like fatigue, the shorter the duration of those side effects,” Dr. Rhodes says. 

Move more often

When you're tired, the thought of physical activity may be daunting in and of itself. And while, yes, increased exercise may be to blame for some forms of fatigue in the first place, research suggests that in some cases (especially where chronic fatigue is concerned), moving your body can be one of the best ways to regain your energy. A systematic review and meta-analysis, for example, found that exercise and overall physical activity significantly reduced fatigue in adults with chronic conditions.

Exercising can also boost your mood and improve your shuteye—two effects that can help you feel more alert and focused during the day. Translation: Less fatigued, more energized. 

Focus on quality sleep

Sleep is a really big component for lowering fatigue when you're on Wegovy, according to Dr. Rhodes. That’s because poor sleep can mess with your energy levels, stress hormones, and how your body processes glucose—all of which can leave you feeling more drained during the day. Plus, better sleep can lead to other advantages like improved efficacy of the medication, she adds.

The general recommendation for adults is to aim for 7–9 hours of shut-eye per night. Practicing good sleep hygiene can help you score ample zzz’s (and, as a result, potentially aid in weight loss, too). This includes:

• Maintaining a consistent sleep schedule wherein you go to bed at the same time every day 

• Keeping your bedroom dark, cool, and quiet 

• Avoiding blue light—such as that emitted from digital devices (e.g. phones, TVs)—close to bedtime 

• Practicing relaxation techniques, such as mindful breathing, meditation, and certain types of stretching, to alleviate tension and help your wind do

• Regularly exercising during the day

Eat a balanced diet

Following an eating plan that focuses on nutrient-dense foods can be key to regaining your energy and fighting fatigue on Wegovy. When feeling tired, and in general for that matter, you want to make sure you’re getting enough nutrients to help your body function optimally. You can do this by prioritizing lean proteins (e.g. eggs, tofu, poultry), whole grains (e.g. quinoa, brown rice), fruits (e.g. berries, apples), vegetables (e.g. leafy greens, broccoli), and healthy fats (e.g. avocado, olive oil). 

A balanced diet composed of these foods can lead to better blood sugar management. This, in turn, can help you experience a steady release of energy during the day vs. spikes and crashes (think: those that often come with eating refined carbohydrates or sugary snacks). 

Stay hydrated

What and how much you drink can also play a part in fatigue. Research looking at progressive fluid restriction found that as participants became more dehydrated, they began to experience changes in mood, sleep quality, and energy levels. Even mild dehydration can lead to increased sleepiness and fatigue, according to the researchers. 

All that’s to say, staying hydrated can help counteract or even prevent feeling tired on Wegovy. While everyone’s hydration requirements vary, experts generally recommend drinking 9–13 cups of water daily. If you’re not a fan of plain H2O, sparkling water, coconut water, and herbal teas can all help you get your fill of fluids without too many extra unnecessary sugars or calories. Plus, some of these alternatives (see: coconut water) can also provide hydration-helping electrolytes. 

Whether or not  Wegovy makes you tired, knowing other potential side effects can be helpful. 

The most common side effects of Wegovy include:

• Nausea

• Constipation

• Diarrhea

• Vomiting

• Abdominal pain

• Headache

• Indigestion and heartburn

• Dizziness

• Bloating

• Belching

• Low blood sugar levels (hypoglycemia)

• Reactions at the injection site (such as redness, swelling, or itching)

In rare cases, Wegovy can cause allergic reactions, pancreatitis, and gallbladder disease. Some studies show an increased association of thyroid tumors or thyroid cancer with Wegovy as well, which is why those with a strong personal or family history are advised against taking the medication. 

"Many times, side effects of semaglutide tend to be more intense or noticeable when you're first taking the medication or increasing the dosage," says Paunel Vukasinov, MD, internal medicine specialist at Medical Offices of Manhattan in New York. "Also, you may notice that side effects change as you're on the medication for a longer period."  

That's why it's helpful to track side effects, he adds. When noting a challenge like Wegovy fatigue or other effects, jot down when they happen, how long they last, and how much they're affecting your everyday activities, Dr. Vukasinov suggests.

As mentioned above, Wegovy side effects tend to dissipate over time. That said, if your symptoms are persistent, interfering with your quality of life, or increasing in severity, be sure to contact your healthcare provider. They may recommend adjusting your Wegovy dosage, switching medications altogether, or exploring other potential causes of your fatigue.

Simply put, does Wegovy make you tired? The answer is: It's a possibility. But you may not experience fatigue constantly, and lifestyle changes can help. Here's a look again at why this may be happening and what you can do:

• Wegovy can help with weight loss and weight management by changing your appetite and reducing calorie consumption.

• While these effects can help you slim down, they can also be to blame for feeling tired on Wegovy. 

• In addition to reduced caloric intake, potential causes of fatigue include low blood sugar, sleep challenges, increased physical activity, metabolic changes, and dehydration.

• Wegovy-related fatigue may lessen over time as your body gets used to the medication.

• Some lifestyle changes can help you regain energy and feel less tired, such as focusing on quality sleep and getting more physical activity.