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Side effect · Wegovy

Fatigue on Wegovy

If you are eating hundreds of calories less than before, feeling tired is often your energy budget talking, not just the drug.

Clinician review pending Updated
On Wegovy
11%
label rate
On placebo
5%
same trials
Extra vs placebo
up to 6points
attributable to the drug, roughly

Placebo-controlled weight-management trials in the Wegovy label (2.4 mg).

Fatigue across GLP-1 medicines

Wegovyplacebo 5%
11.0%
Saxendaplacebo 5%
8.0%
Zepboundplacebo 3%
7.0%
Trulicityplacebo 3%
6.0%
Highest rate across label doses. Different trials and populations, so compare with care.

Why it happens

GLP-1 medicines can cut appetite sharply. A large, sudden calorie drop, especially with low protein and fluids, can leave you tired and weak.

Stomach side effects, poor sleep and low blood sugar in people with diabetes can add to it.

When it starts and fades

Fatigue tends to be most noticeable in the early weeks and after dose increases, when appetite drops the most.

It often improves as you find a sustainable eating pattern. Ongoing exhaustion is worth checking, since it has many possible causes.

What helps

  • Hit a daily protein floor, even on low-appetite days.
  • Eat at regular times rather than going most of the day without food.
  • Drink fluids steadily, and include some electrolytes in hot weather or after exercise.
  • Keep moving with light walks; gentle activity often boosts energy.
  • Protect 7 to 9 hours of sleep.
  • Check whether you are eating far below your calorie target with a quick food log.

Other Wegovy side effects

Nausea44%Diarrhea30%Vomiting24%Constipation24%Stomach pain20%Headache14%Heartburn and indigestion9%Dizziness8%Bloating7%Burping7%Gas6%Low blood sugar6% (people with type 2 diabetes)Hair loss3%

Common questions

How common is fatigue on Wegovy?

In the trials behind the label, 11% of people on Wegovy reported it, vs 5% on placebo.

Why am I so tired on Zepbound?

Eating much less than usual, especially less protein, is a common reason. Fatigue is also listed on the label.

Does GLP-1 fatigue go away?

For many people it improves after the first weeks or once a dose step settles. Raise it with your prescriber if it does not.

How many calories is too few on a GLP-1?

It depends on your size and activity. Sunny Weigh's TDEE on a GLP-1 tool can show where your intake sits compared with your needs.

Sources

  1. Wegovy prescribing information (FDA label on DailyMed)
  2. STEP 1 trial publication

Clinician review pending. Drafted from primary sources and waiting for sign-off by a licensed clinician (MD, DO or PharmD) before launch. Every number is checked against its source. Drug facts are re-checked quarterly, prices monthly and whenever a label changes. How we review · Report an error