A medication like semaglutide can often be what helps people finally reach their weight-loss goals, but that doesn’t mean it’s always a straight line without obstacles. Like most medications, it can come with side effects that take some getting used to. If you’re taking semaglutide, you might experience digestive side effects like nausea and diarrhea. You may notice increased fatigue. 

Quick Answer: Does Semaglutide Make You Tired?

Semaglutide is more likely to cause other side effects, mainly gastrointestinal (GI) or digestive ones like nausea, diarrhea, vomiting, constipation, and stomach pain. However, various side effects are possible, including fatigue.

Is fatigue a known side effect of semaglutide?

Some people do experience fatigue as a side effect of semaglutide. Still, it’s not considered the most common side effect, and the severity and frequency of occurrence can vary among individuals. Many people may experience no fatigue. 

How common is semaglutide fatigue in studies vs real life?

Based on clinical studies, semaglutide is associated with fewer side effects than other drugs. Clinical trials of patients treated with Ozempic (the approved brand-name version for type 2 diabetes) reported that fatigue occurred in more than 0.4% of patients. However, the exact percentage wasn’t given on the label. 

In clinical trials of patients receiving Wegovy (the brand-name version primarily used for weight management), approximately 11%experienced fatigue. In contrast, 5% of patients who received placebo or no treatment experienced fatigue. 

For people taking the oral version of semaglutide (Rybelsus), there were no reports of fatigue on the FDA label. 

Still, the incidence of fatigue is generally lower than that of nausea, which is experienced by 15% to 44% of patients on Ozempic or Wegovy. Even in real-world studies, nausea was the most common side effect, with 37% of patients on semaglutide experiencing nausea or vomiting. 

How Semaglutide Works in Your Body (and Why It Can Affect Energy)

Semaglutide is part of a drug class called glucagon-like peptide-1 (GLP-1) receptor agonists. It works by attaching to GLP-1 receptors in the GI tract (although they’re also found in the brain and other parts of the body). In essence, it mimics the action of GLP-1, a natural hormone that helps manage blood sugar and appetite.

GLP-1 basics: Ozempic, Wegovy, Rybelsus, compounded semaglutide

Semaglutide comes in different forms:

• Ozempic (injection) for type 2 diabetes
• Wegovy (injection) for chronic weight management
• Rybelsus (tablet) for type 2 diabetes

Compounded semaglutide is also an option. It contains the same active ingredient as brand-name versions and should be effective. Compounded versions typically differ in that they contain different inactive ingredients and are produced in compounding pharmacies.

At their core, GLP-1 agonists help increase the release of insulin from the pancreas. They also reduce glucagon secretion, a pancreatic hormone that increases blood glucose levels. As a result, these medications help control blood sugar. 

In addition to their direct effects on glucose, GLP-1 agonists slow gastric emptying and reduce appetite. After eating while taking a GLP-1 drug, many people feel fuller more quickly, which makes it easier to stay on a balanced diet. 

Appetite, calorie intake, and low energy

One of semaglutide’s main effects is reducing appetite. With a lower appetite, you might not eat as many calories as you did before.

Eating fewer calories while taking semaglutide, especially with reduced protein and total calories, may result in less fuel for the body. Therefore, you may feel weaker or more fatigued, particularly as your body adjusts to the medication. 

Blood sugar swings, dehydration, and sleep changes

Besides a reduced appetite, other effects of GLP-1 drugs can cause more tiredness than usual. These include changes in blood glucose, insufficient fluid intake, and sleep disturbances.

• Blood sugar changes: If you have diabetes, especially if you also take insulin or sulfonylureas, fatigue can be an early sign of hypoglycemia.
• Dehydration from gastrointestinal side effects: Nausea, vomiting, and diarrhea can cause fluid loss. Product labels specifically warn about dehydration and kidney problems when GI effects are severe or persistent.
• Sleep changes: Reflux, nausea, constipation, and increased bathroom trips during the night can interrupt sleep. A poor night’s sleep can lead to fatigue.

Since multiple factors can influence how fatigued a person feels while taking semaglutide, it’s best to consult a healthcare provider if this effect persists. 

How Long Does Semaglutide Fatigue Last?

The duration of fatigue depends on the individual and on when and why it occurs. For many people, fatigue is mild and resolves after becoming accustomed to the medication and following a healthy diet and exercise regimen.

Typical timeline when you start or increase your dose

Fatigue might be more noticeable in the first couple of weeks of treatment or around one to two weeks after increasing the dosage. Since many people start a new diet and exercise plan while using semaglutide, it could take time to adjust after beginning treatment or increasing doses. 

When tiredness is likely to improve (and when it might not)

The underlying cause of fatigue will determine how quickly it improves. For example, if early dietary changes are causing fatigue, it may take a week or two to adapt to a new diet alongside the new drug. As nausea and sleep changes improve, fatigue usually gets better as well.

Fatigue might take longer to improve in the following cases:

• You’re consistently under-eating (especially protein)
• Constipation is persistent
• You’re chronically dehydrated
• You’re experiencing mood changes
• Blood sugar is getting low or fluctuating

When fatigue is caused by factors like not eating enough, mood changes, or blood sugar changes, it often doesn’t go away on its own. Feeling better usually means fixing the underlying cause, not just waiting it out.

Normal Tired vs Red-Flag Fatigue: When to Call a Clinician

In most cases, fatigue doesn’t last long. It may also be managed by maintaining a balanced diet and engaging in regular exercise. However, some cases of fatigue may be more severe than others. 

Signs of semaglutide fatigue are probablya  “normal adjustment.”

• You feel mildly to moderately tired after starting semaglutide or increasing your dose
• You’re still able to get through the day, but feel a bit slower or more worn down than usual
• The tiredness improves with regular meals, good hydration, and sleep
• You’re not having severe stomach pain, vomiting, diarrhea, or signs of dehydration

These signs suggest that fatigue is unlikely to be a serious concern and should ease as the body adjusts to the drug.

Severe symptoms (pancreas, kidneys, bowel, thyroid, mental health) that need urgent care

Call your healthcare provider or seek urgent medical care if fatigue comes with red flags like:

• Severe dehydration and stress on the kidneys: Symptoms may include very low urine output, dark urine, severe dizziness, fainting, swelling, and shortness of breath
• Severe stomach or bowel problems: Symptoms may include an inability to keep fluids down, blood in the stool, vomiting, severe constipation with swelling of the abdomen
• Possible pancreatitis: Symptoms include severe upper abdominal pain that may spread to the back, pain that worsens after eating, ongoing nausea or vomiting, fever, or a rapid heartbeat
• Mental health changes: Symptoms to watch for include new or worsening depression, agitation, suicidal thoughts, or other unusual behavior changes

If fatigue continues for several weeks, gets worse, or makes it hard to function in daily life, it’s best to consult a clinician for medical advice.

Does Semaglutide Make You Depressed, Constipated, or Thirsty?

In addition to fatigue, semaglutide may have other related effects. For some, this may mean feeling depressed and experiencing constipation or increased thirst.

Does semaglutide make you depressed or anxious?

Research suggests there may be a link between semaglutide and mood changes, including depression. An extensive real-world study that followed more than 160,000 people found higher rates of depression, anxiety, and suicidal behavior among people prescribed GLP-1 medications like semaglutide. 

At the same time, other studies report the opposite. Some research indicates that GLP-1 drugs may improve mood and overall quality of life. These studies have also found benefits in people with serious mental illness, including alcohol use disorder, and those with a higher suicide risk.

Since the mental health effects of semaglutide can vary, healthcare providers recommend watching for mood changes. The risk of depression or anxiety may vary depending on whether a person has a history of mental illness.

Does semaglutide make you constipated—and can constipation worsen fatigue?

Constipation is a known side effect of semaglutide and other GLP-1 agonists. In large clinical trials, more people taking semaglutide reported constipation than those who didn’t use semaglutide. For example, in the STEP 8 trials, constipation occurred in approximately 39% of patients receiving semaglutide versus 24% of patients receiving placebo. 

There’s also evidence that constipation and fatigue often occur together. A community-based study of older adults found that constipated participants reported significantly higher fatigue than non-constipated participants. While constipation likely doesn’t cause fatigue directly, the discomfort, dehydration, and potential sleep disturbances associated with constipation may indirectly contribute to fatigue. 

Does semaglutide cause thirst or dehydration?

Semaglutide doesn’t directly cause dehydration. Instead, dehydration could be a downstream effect of other side effects of semaglutide, like vomiting and diarrhea. Because it’s easy to lose fluids from these digestive side effects, there’s an increased risk of dehydration. 

Dehydration and feeling thirsty go hand-in-hand. Diarrhea and vomiting can increase fluid needs, which could lead to increased thirst. A common sign of dehydration is feeling more tired than usual. Other symptoms might include dark-colored urine, headache, dry mouth, and dizziness. 

Practical Ways to Fight Semaglutide Fatigue

Fatigue from semaglutide can be managed in various ways. In most cases, you can try different lifestyle changes to help manage the underlying cause of the fatigue.

Hydration and gentle movement

Not drinking enough water or other fluids can contribute to fatigue, especially if you’re also experiencing nausea or diarrhea. Maintaining adequate hydration can support the kidneys and promote healthy energy levels. In addition to staying hydrated, light movement or exercise can help boost overall energy levels and manage sluggishness. 

Eating enough protein and calories on semaglutide

Many people taking semaglutide tend to undereat due to reduced appetite. Even if weight loss is the goal, insufficient protein or total calories may contribute to fatigue. That’s why it’s important to eat nutrient-dense foods to help keep energy levels steady.

Helpful strategies might include:

• Eating protein first at meals, even if portions are small
• Eating smaller meals throughout the day
• Choosing protein options that are softer or easier to digest if nausea is an issue

Sleep hygiene and pacing your day

Side effects such as nausea and constipation can cause sleep changes, which could have a cascading effect. For example, a poor night’s sleep can exacerbate fatigue the next day. Therefore, it may come down to monitoring your sleep habits to ensure you’re getting enough rest. 

Good sleep hygiene habits may include:

• Keeping a consistent sleep and wake time
• Avoiding large meals close to bedtime
• Planning heavy tasks earlier in the day and having rest breaks

Dose timing, titration, and working with your telehealth clinician

Fatigue may be more common when starting semaglutide or after a dose increase. Sometimes the solution isn’t lifestyle changes alone, but instead changes in how or when the medication is taken. A healthcare provider can provide guidance on managing side effects such as fatigue. For example, your healthcare provider might recommend maintaining a lower dose for a more extended period if side effects do not resolve. 

How OnlineSemaglutide.org Telehealth Can Help

Managing fatigue on semaglutide isn’t just about willpower or lifestyle changes. It’s also about having the proper clinical support at the right time. In many cases, healthcare providers are easily accessible online. They can find out the underlying cause of fatigue or other side effects and adjust the treatment plan as needed.

What to expect from an online fatigue + side-effect check-in

During a telehealth visit, your clinician will examine multiple patterns, not just symptoms. They might ask about when fatigue started, how it aligns with previous dose changes, and whether you have gastrointestinal side effects such as nausea or constipation. 

Based on that, they can suggest changes, such as slowing the dosing schedule or implementing specific dietary strategies. The goal is to reduce side effects while maximizing the drug’s benefit.

When switching to another medication might be discussed

If fatigue or gastrointestinal side effects persist despite lifestyle and dosage changes, a healthcare provider may recommend alternative medications. Different GLP-1 agonists or other drugs may be considered. For example, tirzepatide acts at both GLP-1 and GIP receptors, and some individuals may tolerate it differently than semaglutide.

Depending on where you are in treatment, the goal may shift toward managing side effects rather than losing as much weight as possible. If you’ve been on semaglide for a while and have experienced some weight loss, it may not be harmful to stay on the same maintenance dose to avoid long-term side effects. 

FAQs: Semaglutide Fatigue, Mood, and Energy

Why am I so tired on semaglutide all of a sudden?

Fatigue while taking semaglutide may be associated with inadequate daily caloric intake, blood glucose fluctuations, and dehydration or sleep disturbances due to GI effects such as nausea and diarrhea. Side effects from the drug typically occur at the start of treatment or during dose increases. 

Can semaglutide cause drowsiness at specific times of day?

It might feel like semaglutide is causing drowsiness at specific times of the day, especially if you’re eating smaller meals. Dehydration and changes in blood glucose levels can also cause increased fatigue. 

Can I exercise if semaglutide causes fatigue?

Even if you feel fatigued on semaglutide, light or moderate activity may be beneficial. If you experience increased drowsiness, dehydration, or severe symptoms of hypoglycemia such as shakiness and confusion, it’s best to consult a healthcare provider. 

Is fatigue more common with Wegovy than with Ozempic or oral semaglutide?

Based on clinical trial data reported in the drug labels, fatigue appears to be more common with Wegovy. Data from FDA labels show a lower rate of fatigue with Ozempic compared with Wegovy, whereas Rybelsus, the oral formulation of semaglutide, doesn’t appear to cause fatigue.