Key takeaways
Fatigue isn’t a common Wegovy side effect; it impacts about 11% of patients and usually subsides over time.
The most common Wegovy side effects are nausea, constipation or diarrhea, and vomiting—gastrointestinal side effects that may contribute to Wegovy fatigue.
Balanced meals, hydration, exercise, sleep, and professional health care can combat Wegovy fatigue.
Wegovy (semaglutide) is an injectable prescription medication approved by the Food and Drug Administration (FDA) for obesity treatment and chronic weight management. Semaglutide mimics a hormone that controls hunger, so it helps reduce your appetite. Wegovy is self-administered once weekly alongside increased exercise and a reduced-calorie diet.
Fatigue is a possible Wegovy side effect, although it’s not the most common adverse reaction. We’ll explain why Wegovy might make you tired, how to improve Wegovy fatigue, and how to manage Wegovy side effects overall.
Why does Wegovy make you tired?
Fatigue isn’t a common Wegovy side effect. In clinical trials, fatigue affected 11% of Wegovy patients, making it the seventh most common side effect. Gastrointestinal side effects are more common, with nausea, diarrhea, and vomiting showing up most often in clinical trials. But remember that side effects will vary from one person to another—everyone metabolizes and tolerates drugs differently.
Wegovy dosage increases gradually over 16–20 weeks. This slow buildup helps temper gastrointestinal side effects. During this period, some people experience temporary fatigue. Possible causes of Wegovy fatigue include gastrointestinal side effects, decreased appetite and caloric intake, and hormonal changes.
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Gastrointestinal side effects may induce fatigue
Gastrointestinal issues like nausea and diarrhea are more common Wegovy side effects than fatigue. But Wegovy’s gastrointestinal side effects can sometimes cause Wegovy fatigue: “[Fatigue] may also be linked to gastrointestinal side effects like diarrhea that can cause dehydration or electrolyte disturbances,” said Eldad Einav, MD, board-certified cardiologist and obesity medicine specialist at Drugwatch.
The body needs to adjust to semaglutide
Wegovy’s active ingredient, semaglutide, belongs to a family of drugs called glucagon-like peptide-1 (GLP-1) receptor agonists). Some people feel temporarily tired while the body acclimates to GLP-1 agonists. “Fatigue associated with semaglutide often improves after several weeks of treatment and typically stabilizes once the medication dosage is no longer being increased,” Einav said.
Appetite suppression may mean fewer calories and less energy
Wegovy curbs hunger, often resulting in lower calorie consumption. “This lower energy intake can result in less fuel for the body to convert into energy, thereby potentially causing feelings of tiredness or fatigue,” said Scott Keatley, registered dietitian and co-owner of Keatley MNT.
Appetite suppressants can sometimes lead to undernourishment. You’ll need to make a point of eating enough, even if you’re not feeling hungry. “Our bodies are finely tuned and require a certain amount of energy to keep us going,” said Emily Van Eck, a registered dietitian. “If you’re taking Wegovy, Ozempic, or other weight loss drugs and, as a result, are under-nourished, it’s likely you’ll feel exhausted throughout the day.”
Hormonal changes may delay energy release
“Additionally, hormonal changes influenced by the medication can affect energy levels,” Keatley said. “Even if you are eating similar amounts [as you did before taking Wegovy], the rate of gastric emptying (the rate at which food moves from the stomach to the small intestine) is slower and will delay your body getting energy from food.”
How to improve semaglutide fatigue
Semaglutide fatigue usually diminishes after several weeks of treatment as your body acclimates. In the meantime, lifestyle changes can help compensate for tiredness. To combat Wegovy fatigue, healthcare professionals recommend exercising, sleeping well, maintaining a balanced diet, and staying hydrated.
Exercise
Increased exercise is already part of Wegovy’s treatment plan for patients, and luckily, it can also help combat tiredness. “Incorporating regular physical activity into one’s routine not only enhances energy levels but also promotes overall well-being. Exercise stimulates endorphin release, which counteracts fatigue and boosts mood,” said Brette Dille, a physician’s assistant at Restore Care, specializing in weight management and pharmacotherapy.
Sleep
Solidifying your sleep routine can also serve as a defense against Wegovy fatigue. “Establishing a regular sleep schedule, creating a conducive sleep environment, and avoiding stimulants close to bedtime are effective strategies,” Dille said.
Balanced diet
A nutrient-rich diet can help boost your energy. Dehydration can also worsen fatigue, so drinking plenty of water is crucial.
Make sure you’re eating enough while using Wegovy. “If you’re feeling tired, you want to be honest with yourself about how much you’re eating,” Van Eck said. “Slow weight loss, while it may not be as exciting, is much better for your health and will make you feel more energized. You want to eat breakfast, lunch, and dinner every day, and maybe a snack also.” Van Eck recommends seeking out eating disorder resources if Wegovy use leads to anorexia or binge eating.
Complex carbohydrates, such as whole grains, fruits, and vegetables, can help stabilize blood sugar and offer a steady energy source throughout the day, according to Trista Best, a registered dietitian at Balance One Supplements. “Additionally, including lean proteins, healthy fats, and fiber-rich foods in your meals can further support energy production and promote satiety.”
“Avoiding excessive caffeine and sugary foods can help prevent energy crashes and maintain more stable energy levels,” Best continued. She suggests seeing a dietitian or healthcare provider to create a tailored nutrition plan that meets your needs and boosts energy while on Wegovy or similar medications.
Common Wegovy side effects
Gastrointestinal issues are the most common side effects for Wegovy patients. Nausea is the most common Wegovy side effect, affecting 44% of patients in clinical trials. Diarrhea, constipation, and vomiting are the next most common. Fatigue is less common, affecting 11% of patients during trials. Less than 7% of clinical trial participants opted to discontinue Wegovy after adverse side effects.
10 most common Wegovy side effects:*
- Nausea (44%)
- Diarrhea (30%)
- Vomiting (24%)
- Constipation (24%)
- Abdominal pain (20%)
- Headache (14%)
- Fatigue (11%)
- Dyspepsia (9%)
- Dizziness (8%)
- Abdominal distension (7%)
*Percentages indicate how many clinical trial participants experienced each Wegovy side effect during three Phase 3 weight-management clinical trials.
Other serious reactions include but aren’t limited to:
- Vision changes (may worsen diabetic retinopathy in people with diabetes)
- Suicidal thoughts or behavior
- Gallbladder problems
- Pancreas problems
- Kidney problems
- Low blood sugar
Wegovy also carries a boxed warning, the FDA’s strongest warning for medications that may cause severe or life-threatening side effects. Wegovy’s boxed warning states that semaglutide has caused thyroid tumors in animals, although its effects on humans are unclear.
You should not take Wegovy if you have Multiple Endocrine Neoplasia syndrome type 2 (MEN 2) or if you have a personal or family history of medullary thyroid carcinoma (MTC). People who use Wegovy should watch for any possible symptoms of thyroid tumors, including shortness of breath, difficulty swallowing, a hoarse voice, or a lump in the neck.
Allergic reactions are rare with Wegovy. Seek emergency help if you have symptoms such as hives, swelling of the face, throat, lips, or tongue, or difficulty swallowing or breathing. The side effects outlined above aren’t comprehensive. Consult your healthcare provider to learn more about Wegovy’s side effects.
Managing Wegovy side effects
Wegovy’s manufacturer, Novo Nordisk, shares tips for managing Wegovy side effects, including nausea:
- Eat bland, low-fat foods, like crackers, toast, and rice.
- Eat foods that contain water, like soups and gelatin.
- Avoid lying down right after you eat.
- Go outdoors for fresh air.
- Eat more slowly.
Keep your healthcare provider informed if you experience any Wegovy side effects. They can adjust your treatment plan or offer solutions to mitigate unwanted effects. Dille points out that “individuals with pre-existing medical conditions such as thyroid disorders, anemia, or sleep disorders may be more susceptible to fatigue and require closer monitoring.”
Einav recommends seeing your healthcare provider about Wegovy fatigue if:
- The symptom worsens or doesn’t improve over time.
- You suspect other underlying causes, such as severe dehydration, nutritional deficiencies, or significant changes in sleep patterns.
- You experience persistent gastrointestinal issues like diarrhea, constipation, or abdominal discomfort, as these can indicate a more serious issue.
Bottom line
While fatigue isn’t the most common side effect of Wegovy, it can still happen, partially due to the medication’s impact on your appetite and gastrointestinal system. It may happen with other semaglutide medications, like Ozempic, as well. Most people find this fatigue diminishes over time as their bodies adjust to the medication.
To manage Wegovy-related fatigue, maintain a balanced diet, stay hydrated, stay active, and get adequate sleep. If Wegovy fatigue persists or worsens, or if you notice other worrisome symptoms, consult your healthcare provider. They can rule out potential causes and adjust your treatment plan if needed.
Sources
- FDA approves new drug treatment for chronic weight management, first since 2014, Food and Drug Administration (2021)
- Wegovy efficacy & safety profile, Novo Nordisk
- Semaglutide injection, National Library of Medicine MedlinePlus (2023)
- Common side effects of Wegovy®, Novo Nordisk