Do GLP-1 Medications Cause Fatigue?

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Short answer: Does tirzepatide make you tired? Fatigue is one of the listed tirzepatide side effects. The Zepbound (tirzepatide) prescribing information lists fatigue in 5% to 7% of people in its weight-loss trials, depending on dose, compared with 3% on placebo. The Wegovy (semaglutide) prescribing information lists fatigue in 11% of people on the 2.4 mg dose, compared with 5% on placebo, while the diabetes versions, Mounjaro and Ozempic, do not include fatigue in their main side-effect tables. If tiredness is new, severe or not going away, talk to a licensed provider.

Does tirzepatide make you tired?

The Zepbound prescribing information lists fatigue as a common side effect. Its main side-effect table pools two placebo-controlled weight-loss trials in which 2,519 adults took Zepbound for up to 72 weeks. The table includes reactions reported in at least 2% of people on Zepbound and more often than on placebo (Zepbound prescribing information). One of those two trials, SURMOUNT-1, enrolled 2,539 adults with obesity or overweight who did not have diabetes (Jastreboff et al., 2022).

Group in the Zepbound trials	People	Reported fatigue
Placebo	958	3%
Zepbound 5 mg	630	5%
Zepbound 10 mg	948	6%
Zepbound 15 mg	941	7%

The prescribing information counts four terms together as “fatigue”: asthenia (weakness), fatigue, lethargy and malaise. The Zepbound Medication Guide, the patient section of the prescribing information, lists “feeling tired” among the most common side effects (Zepbound prescribing information). Our tirzepatide dosage chart shows how the dose steps work.

What does the Mounjaro prescribing information say?

Mounjaro is the same drug, tirzepatide, indicated for type 2 diabetes. Its main side-effect table covers reactions reported in at least 5% of people on Mounjaro and more often than on placebo, and it lists nausea, diarrhea, decreased appetite, vomiting, constipation, indigestion and abdominal pain. Fatigue is not in that table (Mounjaro prescribing information).

The Mounjaro prescribing information does mention fatigue from a separate heart-outcomes trial. In that trial, 6,647 adults with type 2 diabetes and heart disease took Mounjaro, and it reports fatigue in 10% of them. That trial compared Mounjaro with another diabetes drug, dulaglutide, rather than with placebo, so it has no placebo rate to compare against (Mounjaro prescribing information).

Does semaglutide make you tired?

The Wegovy prescribing information lists fatigue as a common side effect. In three placebo-controlled trials, 2,116 adults took Wegovy 2.4 mg for up to 68 weeks. It reports fatigue in 11% of them, compared with 5% of 1,261 people on placebo, and it counts fatigue and asthenia together (Wegovy prescribing information).

The current prescribing information also has a table for the higher 7.2 mg dose, from two 72-week trials with three arms (Wegovy prescribing information):

Group in the Wegovy 7.2 mg trials	People	Reported fatigue
Placebo	303	5%
Wegovy 2.4 mg	304	9%
Wegovy 7.2 mg	1,311	11%

The Wegovy Medication Guide lists “tiredness (fatigue)” among its common side effects (Wegovy prescribing information).

What does the Ozempic prescribing information say?

Ozempic is semaglutide indicated for type 2 diabetes. Its main side-effect table uses a 5% cutoff and does not include fatigue. Elsewhere in the same section, it says: “Other adverse reactions with a frequency of >0.4% were associated with OZEMPIC include fatigue, dysgeusia and dizziness.” It does not give a fatigue percentage (Ozempic prescribing information).

Fatigue rates for four GLP-1 drugs at a glance

Drug	Ingredient and use	Trials in the table	Fatigue on the drug	Comparison group
Zepbound	Tirzepatide, weight reduction	2 trials, up to 72 weeks	5% (5 mg), 6% (10 mg), 7% (15 mg)	3% placebo
Mounjaro	Tirzepatide, type 2 diabetes	Placebo pool (5% cutoff)	Not in the table; 10% in a heart-outcomes trial	Heart trial used dulaglutide, not placebo
Wegovy	Semaglutide, weight reduction	3 trials, up to 68 weeks (2.4 mg); 2 trials, 72 weeks (7.2 mg)	11% (2.4 mg); 9% (2.4 mg) and 11% (7.2 mg) in the 7.2 mg trials	5% placebo in both
Ozempic	Semaglutide, type 2 diabetes	Placebo pool (5% cutoff)	Not in the table; listed among reactions above 0.4%	No fatigue figure given

Why do the numbers differ between drugs?

The prescribing documents themselves give the main reasons. Each one notes that clinical trials are run under widely varying conditions, so side-effect rates from one drug’s trials “cannot be directly compared to rates in the clinical studies of another drug and may not reflect the rates observed in practice” (Wegovy prescribing information; Zepbound prescribing information).

The tables are also built differently. Zepbound and Wegovy list reactions seen in at least 2% of people, while Mounjaro and Ozempic use a 5% cutoff. Zepbound groups four terms under “fatigue” and Wegovy groups two. The trials also enrolled different people: weight-loss trials for Zepbound and Wegovy, and type 2 diabetes trials for Mounjaro and Ozempic (Mounjaro prescribing information; Ozempic prescribing information). For a broader comparison of the two drugs, see tirzepatide vs semaglutide.

What else does the Zepbound prescribing information describe?

The Zepbound prescribing information also describes these side effects. Drowsiness appears among its listed signs of low blood sugar:

• Low blood sugar. The Zepbound Medication Guide lists signs that may include dizziness or light-headedness, sweating, confusion or drowsiness, headache, blurred vision, slurred speech, shakiness and a fast heartbeat. It says the risk may be higher with medicines that can cause low blood sugar, such as insulin or a sulfonylurea (Zepbound prescribing information).
• Low blood pressure. In the Zepbound weight-loss trials, hypotension was reported in 1.6% of people on Zepbound vs 0.1% on placebo, and it notes this also occurred along with stomach side effects and dehydration (Zepbound prescribing information).
• Dehydration. The Zepbound Medication Guide says diarrhea, nausea and vomiting may cause a loss of fluids, which may cause kidney problems, and tells patients to tell their provider right away if these do not go away (Zepbound prescribing information).

The full side-effect tables for semaglutide are on our semaglutide side effects page.

Do compounded semaglutide and tirzepatide list fatigue?

The figures on this page come from trials of the branded drugs Zepbound, Mounjaro, Wegovy and Ozempic, as reported in their prescribing information. Those trials did not study compounded semaglutide or compounded tirzepatide.

When should you talk to a licensed provider?

Talk to a licensed provider if tiredness is new, severe or not going away while you take a GLP-1 medication. The Zepbound and Wegovy prescribing information also describes signs that need prompt attention (Zepbound prescribing information; Wegovy prescribing information):

• Severe pain in the stomach area that will not go away, with or without nausea or vomiting (the prescribing information names possible pancreatitis)
• Pain in the upper stomach, fever, yellowing of the skin or eyes, or clay-colored stools (the prescribing information names possible gallbladder problems)
• Signs of low blood sugar, especially if you also take insulin or a sulfonylurea
• Nausea, vomiting or diarrhea that does not go away

Your provider sets the dose. For questions about missed doses and restarting, see our GLP-1 missed dose and side effects guide.

GLP-1 fatigue FAQ

Is fatigue a side effect of Mounjaro?

Fatigue is not in the main side-effect table of the Mounjaro prescribing information, which lists reactions seen in at least 5% of people and more often than on placebo. It does report fatigue in 10% of 6,647 people on Mounjaro in a heart-outcomes trial that compared it with dulaglutide, not placebo. Talk to a licensed provider about tiredness on any medication.

Does Wegovy make you feel tired?

The Wegovy prescribing information reports fatigue, which it groups with asthenia, in 11% of adults on Wegovy 2.4 mg in its weight-loss trials, compared with 5% on placebo. In the trials of the higher 7.2 mg dose, it was 11% on 7.2 mg, 9% on 2.4 mg and 5% on placebo. The Medication Guide lists “tiredness (fatigue)” as a common side effect.

How do PrescribedRX GLP-1 plans work?

You complete a short online eligibility check. A licensed provider reviews every intake, typically within 48 hours, and a prescription is issued only if a licensed provider determines treatment is appropriate. Prescriptions are written by state-licensed clinicians through Telegra MD and filled by licensed partner pharmacies, with free priority shipping. Plans are self-pay, and availability varies by state. Both medications are compounded. Compounded medications are prepared by licensed pharmacies and are not FDA-approved. Prices as shown on prescribedrx.com in October 2026:

Plan	Price as shown on the site
Compounded tirzepatide	3 month plan $597 · $199/mo · Billed every 3 months. Cancel anytime.
Compounded semaglutide	3 month plan $420 · $140/mo · Billed every 3 months. Cancel anytime.

Have questions about GLP-1 treatment?

A prescription is issued only if a licensed provider determines treatment is appropriate, and your provider sets the dose. Take the eligibility quiz or explore compounded GLP-1 plans on our weight loss page.

Related reading: do GLP-1 medications cause hair loss?

Sources

1. DailyMed. Zepbound (tirzepatide) injection, prescribing information and Medication Guide. National Library of Medicine, NIH. dailymed.nlm.nih.gov. Accessed Oct 2026.
2. DailyMed. Mounjaro (tirzepatide) injection, prescribing information. National Library of Medicine, NIH. dailymed.nlm.nih.gov. Accessed Oct 2026.
3. DailyMed. Wegovy (semaglutide) injection and tablets, prescribing information and Medication Guide. National Library of Medicine, NIH. dailymed.nlm.nih.gov. Accessed Oct 2026.
4. DailyMed. Ozempic (semaglutide) injection, prescribing information. National Library of Medicine, NIH. dailymed.nlm.nih.gov. Accessed Oct 2026.
5. Jastreboff AM, Aronne LJ, Ahmad NN, et al. Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1). N Engl J Med. 2022;387(3):205-216. PubMed. Accessed Oct 2026.

This article is for general information. It is not medical advice and it is not a recommendation for any particular treatment. Whether a treatment is appropriate for you is a decision for a licensed clinician who has reviewed your health history and current medications.