Fatigue is a listed tirzepatide side effect. What the Zepbound label reports, what else causes tiredness, and when to call your provider.
It can. Tiredness is a listed side effect of tirzepatide, but it is not one of the most common ones. In the Zepbound prescribing information, fatigue was reported by 3% of people on placebo and by 5% to 7% of people on tirzepatide, depending on the dose. So if you are asking “does tirzepatide make you tired,” the honest answer is: for some people, yes, and often other things are adding to it. This guide covers what the label says, what else can cause tiredness, and when to call your provider.
This article is general information, not medical advice or a dose recommendation. Your prescribing provider sets your dose.
Does tirzepatide cause fatigue?
Yes, it can. The Zepbound label lists “fatigue” among adverse reactions reported in at least 2% of people and more often than with placebo. The label groups several words under that one heading: asthenia (weakness), fatigue, lethargy and malaise (a general unwell feeling). The numbers below come from the label’s two weight reduction and long-term maintenance trials.
| Group | People | Reported fatigue |
|---|---|---|
| Placebo | 958 | 3% |
| Zepbound 5 mg | 630 | 5% |
| Zepbound 10 mg | 948 | 6% |
| Zepbound 15 mg | 941 | 7% |
Source: Zepbound prescribing information, section 6.1, Table 1, on DailyMed (updated August 2026 when we checked). Labels change, so always read the current version.
Two things stand out. Most people did not report fatigue at all, and the share who did rose a little with the dose. Tirzepatide is also the ingredient in Mounjaro, but we quote only the Zepbound table here because that is the one we checked line by line.
Why might tirzepatide make you tired?
The label does not say why fatigue happens, so we will not guess at a mechanism. What the label and general health sources do show is a set of things that often come with starting a GLP-1 medicine and can leave you drained:
- Eating much less. The medicine lowers appetite, and a big drop in food can mean less energy. Our guide on what to eat on a GLP-1 covers eating enough protein and regular meals.
- Dehydration. The Zepbound label says kidney problems seen after the drug was on the market mostly happened in people who had nausea, vomiting or diarrhea that led to dehydration. MedlinePlus lists feeling tired and dizziness among the signs of dehydration.
- Low blood sugar. The label says Zepbound lowers blood glucose and can cause hypoglycemia. In a trial of people with type 2 diabetes, the risk was higher with a sulfonylurea: 10.3% versus 2.1% without one.
- Low blood pressure. The label reports hypotension more often with Zepbound (1.6%) than with placebo (0.1%), and says it also occurred together with stomach side effects and dehydration.
What else can cause tiredness?
MedlinePlus says fatigue is a symptom, not a disease, and lists many possible causes. Some are easy to overlook while you are focused on a new medicine:
- Not getting enough sleep, or staying up too late.
- Too much caffeine or alcohol, and too little or too much exercise.
- Medical problems such as anemia, thyroid or kidney disease, sleep apnea, depression and anxiety.
- Certain medicines, including some antidepressants, antihistamines, and medicines for nausea and pain.
This is why a provider asks about sleep, food, activity and other medicines before putting tiredness down to one cause.
When does tiredness usually show up?
The label tables above do not break fatigue down by week, so we cannot give you a timeline. We can say that the rates rose a little with the dose, which is a reason to mention tiredness to your provider if it starts or gets worse after a change. Our guide to side effects as the dose changes explains how the clinic’s published schedule works.
What can you do about it?
These are general steps, not instructions to change your treatment:
- Keep track of when the tiredness happens, and what you ate and drank that day.
- Drink fluids through the day. MedlinePlus says mild dehydration may need only more water.
- Aim for regular meals that include protein, rather than skipping food because your appetite is low.
- Protect your sleep, and go easy on caffeine and alcohol.
- Tell your provider before you skip, delay or change a dose. Never adjust it yourself.
When should you call your provider?
MedlinePlus advises contacting your provider if you have been tired for weeks. Get medical help right away if tiredness comes with confusion, fainting, a rapid heartbeat, rapid breathing, or not urinating, because MedlinePlus lists these as warning signs of serious dehydration. Also call if you have shakiness, sweating or confusion that could point to low blood sugar, or if your tiredness is severe or does not improve.
Frequently asked questions
Does tirzepatide make you tired?
It can. In the Zepbound label’s weight trials, 5% to 7% of people on tirzepatide reported fatigue, compared with 3% on placebo.
Is fatigue a common side effect of tirzepatide?
It is listed, but it is not among the most common. Most people in the trials did not report it, and the share who did rose slightly with the dose.
Why am I so tired on tirzepatide?
Several things can contribute, including eating too little, dehydration, low blood sugar, poor sleep and other medicines. Your provider can help work out which apply to you.
Does tiredness go away on tirzepatide?
The label does not give a timeline for fatigue. If you have been tired for weeks, MedlinePlus advises contacting your provider.
Can dehydration make tirzepatide fatigue worse?
It can add to it. MedlinePlus lists tiredness and dizziness as signs of dehydration, and the Zepbound label links dehydration to nausea, vomiting and diarrhea.
Should I stop tirzepatide if I feel tired?
Do not stop or change your dose on your own. Talk to your prescribing provider, who can check for other causes and decide what is right for you.
Sources
More from this guide series
Next step
To see whether a prescribed GLP-1 is right for you, start the free intake form. The clinic will contact you to schedule an appointment, and a licensed provider reviews your health before anything is prescribed. You can also see the current plans on the tirzepatide pricing and programs page.