Tiredness on Ozempic, Wegovy, Mounjaro and Zepbound: all four labels list fatigue

Fatigue on each label

Each figure below carries the trial it came from and what the label counted as fatigue, because the four don’t count the same thing.

Zepbound’s row gathers four terms and Wegovy’s two, in different trials, so the two rates can’t be set against each other. The labels themselves say that rates from one drug’s trials “cannot be directly compared” with another’s. The stomach side effects are set out the same way, each with its own trials, on side effect rates, label by label.

Wegovy

In three trials of up to 68 weeks, 11% of adults on Wegovy 2.4 mg reported fatigue, against 5% on placebo. Only headache and five stomach-related reactions were reported more often on Wegovy in that table. The Medication Guide puts “tiredness (fatigue)” on its list of the most common side effects.

The 7.2 mg dose was tested in two 72-week trials against both placebo and 2.4 mg. Fatigue went up with the dose: 5% on placebo, 9% on 2.4 mg and 11% on 7.2 mg.

The trial in patients aged 12 and older lists reactions seen in at least 3% and more often than on placebo, and fatigue isn’t among them. The 25 mg tablet has no fatigue figure of its own; per the label, the common reactions in its trial were “similar to those listed in Table 3”.

Zepbound

Zepbound’s pooled table puts fatigue at 5% on 5 mg, 6% on 10 mg and 7% on 15 mg, against 3% on placebo, in two trials of up to 72 weeks. Each dose step adds a point.

Its row counts four terms: asthenia, fatigue, lethargy and malaise. In the Medication Guide the same entry reads “feeling tired”, one of the most common side effects it lists. Two trials in adults with obstructive sleep apnea reported adverse reactions similar to the weight trials, with no separate fatigue figure.

Ozempic and Mounjaro

Ozempic’s label lists fatigue under “Other adverse reactions with a frequency of >0.4%”, next to dysgeusia and dizziness. That’s a floor, not a rate: fatigue was reported by more than 0.4% of patients, and the label says no more than that. It isn’t on the Medication Guide’s list of the most common side effects.

Mounjaro’s placebo-controlled table lists reactions seen in at least 5% of patients and more often than on placebo, and it has no fatigue row. The one Mounjaro figure comes from SURPASS-CVOT, a heart-outcomes trial in adults with type 2 diabetes and established cardiovascular disease: among 6,647 exposed to Mounjaro, 10% reported fatigue. That trial compared Mounjaro with dulaglutide, another GLP-1 drug, rather than placebo, and the label doesn’t give dulaglutide’s fatigue rate. So 10% says how often fatigue came up, not how much of it the drug caused.

Drowsiness and weakness on the warning lists

All four Medication Guides list “confusion or drowsiness” and “weakness” among the signs of low blood sugar, alongside shakiness, sweating, hunger and a fast heartbeat. Three of them tie the higher risk to taking the drug with another medicine that lowers blood sugar. Ozempic’s reads: “Your risk for getting low blood sugar may be higher if you use OZEMPIC with another medicine that can cause low blood sugar, such as a sulfonylurea or insulin.” Wegovy’s places the risk in patients with type 2 diabetes, especially those also taking insulin or a sulfonylurea.

That’s a separate entry from fatigue, and none of the four labels links the two. Which diabetes medicines each label flags is set out in the drug interactions page. Hair loss, the other side effect people ask about that isn’t a stomach complaint, sits in the same weight-label tables.

Sources

See the providers

Fatigue is a property of the drug, not the seller. The boards list who sells each molecule and what each one publishes.

• Semaglutide providersprovider board

  Readers who have settled on semaglutide and are choosing who to buy it from.

• Tirzepatide providersprovider board

  Readers who have settled on tirzepatide and are choosing who to buy it from.

More, read from the same labels

• Semaglutide vs tirzepatidereading the label

  What the four FDA-approved labels say each molecule is, what each is approved to treat, and where the two differ.

• How they workreading the label

  The receptor each molecule switches on, what the labels say that does to appetite, blood sugar and the stomach, and why one dose lasts a week.

• Dose escalation schedulesreading the label

  The starting dose, the escalation interval and the maximum dose each label sets, and why they are not interchangeable.

• Side effect ratesreading the label

  What each label reports for nausea, vomiting, diarrhea and constipation — and the sentence every label prints above those numbers.

• Hair lossreading the label

  Which labels report hair loss, the rate against placebo where a trial measured it, and why two of them put no number on it.

• Missed dose rulesreading the label

  The window each label gives for a late dose, and the minimum gap it requires when the injection day changes.

• Drug interactionsreading the label

  Insulin and sulfonylureas, oral medications, and the oral-contraceptive precaution that appears on two of these four labels and not the other two.

• Buying one onlinereading the label

  The agency's own warning signs for a telehealth GLP-1 seller, its 28-day vial rule, and what it says about drugs that arrive warm.

• Refrigeration and storagereading the label

  How cold each pen is kept, how many days it can spend at room temperature, and what the labels say about heat and freezing.

• Who should not take onereading the label

  The boxed warning every one of these labels carries, the two contraindications, and which warnings appear on which product.