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What to Do if Ozempic Makes You Tired, According to Weight Loss Doctors

This rare side effect can get in the way of your fitness journey.
By Rebekah Harding
May 21, 2024

30-Second Takeaway

  • Tiredness and fatigue are potential side effects of Ozempic.
  • This side effect is rare, only affecting around 0.4 percent of people on the medication, and tends to resolve as your body adjusts.
  • Experts suspect that this fatigue may be due to caloric deficit or low blood sugar.
  • Changes to dosage, diet, and sleep may help reduce tiredness on Ozempic.

If you’ve struggled to lose weight, you may have turned to Ozempic (semaglutide) to supplement your workout routine and healthy diet. But some Ozempic users say that the weight-loss injection has made them excessively tired, getting in the way of their fitness progress. 

The side effect is rare, and “it’s unknown exactly why it occurs,” says lifestyle medicine physician John Sosa, M.D. 

Here’s what to do if it happens to you — and hint, you don’t have to stop taking the medication.

Does Ozempic Make You Tired?

It can, but it’s a rare side effect. Ozempic is a brand-name semaglutide injection which belongs to a class of medications called GLP-1 agonists. Ozempic is approved by the U.S. Food and Drug Administration to treat type 2 diabetes, but its ability to lessen cravings and appetite has made it popular for weight loss. (Wegovy, a higher-dose semaglutide marketed specifically for weight loss, is also popular.) 

Excessive fatigue isn’t a common side effect of semaglutide, according to Sosa. In clinical trials, only 0.4 percent of people on Ozempic reported fatigue as a side effect (1). 

Still, it’s not unheard of to be more tired than usual while your body adjusts to Ozempic. Sosa says that tiredness usually kicks in within a few days of starting the once-weekly injections, and may get worse if your doctor ups your dose. This checks out: Eleven percent of people who took Wegovy experienced bouts of fatigue after starting treatment in clinical trials (2). 

In most cases, your body will naturally adjust to the medication, per gastroenterologist Steven Batash, M.D. This side effect—like other side effects including GI issues—should go away a couple of weeks into treatment.

About the Experts

Dr. John Sosa, M.D., is a board-certified family and lifestyle medicine physician who specializes in medical weight loss.

Dr. Steven Batash, M.D., is a board-certified gastroenterologist and leading physician at the Batash Endoscopic Weight Loss Center.

Ozempic lowers blood sugar levels

Ozempic is prescribed to people with type 2 diabetes, who may take the medication with other prescriptions like insulin or sulfonylureas (hormones that lower blood sugar levels).

Drug interactions between semaglutide and other diabetes medications can cause low blood sugar, says Batash. If your blood sugar levels drop too low, you might feel “weak or drowsy.” 

You may not eat enough calories

Semaglutide curbs cravings by mimicking GLP-1, a hormone your body releases after detecting nutrients (3). GLP-1 medications trick your body into thinking you’ve eaten, which effectively curbs cravings and reduces your appetite. 

Sosa notes that any unusual tiredness after starting Ozempic is “likely from the reduced calorie intake from eating less overall.”

Considering Ozempic?

Other Ozempic Side Effects

Tiredness isn’t a common side effect of Ozempic. But you may notice other, more common reactions to starting semaglutide, including (4):

Side effects tend to pop up periodically as you increase your semaglutide dose, and then scale back once your body adjusts. 

What to Do if Ozempic Makes You Tired

Being more tired than usual after starting semaglutide injections isn’t dangerous. But fatigue can get in the way of your gym and body-composition goals. Batash and Sosa recommend these lifestyle tweaks to improve your energy levels after starting Ozempic:

Prioritize sleep

Sosa and Batash emphasize the need for plenty of rest—especially if your energy levels dive after starting Ozempic. The Centers for Disease Control recommends that all adults clock in 7 to 9 hours of sleep every night. 

Not getting enough sleep can exacerbate blood sugar fluctuations, which you may already be dealing with on Ozempic. A 2021 clinical review found that people with diabetes who have good sleep hygiene have better blood sugar control overall (5). 

To improve your sleep hygiene, the Sleep Foundation recommends:


Eat a balanced diet

Ozempic will make you want to eat less—and that’s okay. But eating a balanced diet full of fiber, protein, and healthy carbs is important for getting the most out of your treatment and avoiding fatigue.

Stay hydrated

Because Ozempic axes your appetite, you may feel less inclined to reach for your water bottle. Semaglutide can also cause mild side effects like vomiting and diarrhea, leading to dehydration. 

Even mild dehydration can decrease physical and cognitive functioning, and energy, according to a study in the journal Nutrition Reviews (6). 

Research suggests that semaglutide may be tough on your kidneys, which makes staying hydrated that much more important (7). Batash urges people on Ozempic to make sure they’re drinking plenty of water to avoid this risk and to boost their energy levels. 

Take vitamin B12

Several compounding pharmacies offer B12 with their semaglutide weight loss treatments—for good reason. Vitamin B12 has been shown across several studies to improve energy levels and blood glucose levels (8, 9). 

If you’re feeling sluggish after starting Ozempic, consider adding B12 to your supplement stack or opting for injections

Vitamin B12, now available from Hone, may boost your energy, reduce stress, and support your brain. Connect with a doctor to see if it’s right for you. 

If switching up your lifestyle doesn’t improve your energy levels, Batash suggests discussing side effects with your GP. “Their doctor may want to run tests like checking blood count, kidney function, and thyroid” to rule out any underlying medical conditions.